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AN INTERNATIONAL WORKSHOP, JUNE 13TH TO 14TH 2016CEST/WIENER NEUSTADT
BIOELECTROCHEMISTRY AND MORE
The AIT Austrian Institute of Technology and CESTinvite you to the lecture series:
Monday, 13th June 2016 – Tuesday, 14th June 2016
Lecture Hall TFZ, 1st floor, Unit A
CEST Centre of Electrochemical Surface Technology
Viktor-Kaplan-Straße 2, 2700 Wiener Neustadt
phone: +43-2622-222266-0 I fax: +43-2622-22266-50
mail: [email protected] I www.cest.at
Date
Location
08:3009:0011:3012:30
12:40
13:20
14:00
14:4015:30
16:10
16:50
17:30
18:10
Monday, June 13th
All Morning: arrival of workshop speakers
Mounting of Posters PhD Student Seminar with Poster SessionLunchWelcomeChristoph Kleber (CEST)Wolfgang Knoll (AIT Austrian Institute of Technology GmbH)Organic Bio-Electronic Sensors for Ultra-Sensitive DetectionLuisa TorsiDielectric and Semiconductor Surface Interfacial Interactions for Biomimetic Integrated Nanosystems Based on Solid-State Nanopores: Nanofluidic-Enabled "Iontronic” Transduction of Biological, Chemical and Physical StimuliOmar AzzaroniInterfacing with the Brain Using Organic ElectronicsGeorges MalliarasCoffee and PostersAnalysis of Molecules and Macromolecules at Electrolyte/Solid Inter-faces – Interface Chemistry, Self-Organization and Interfacial ForcesGuido GrundmeierDetection of Unlabeled Biomolecules Using Simplified Reflective Inter-ferometryLewis RothbergElectrochemical Biosensor Systems for POC DiagnosticsMartin WeberA Decaheme Cytochrome as a Molecular Electron Conduit in Dye-Sensitized PhotoanodesLars J. C. Jeuken End of Lecture Day 1
BIOELECTROCHEMISTRY AND MORE
09:00
09:40
10:20
11:0011:30
12:10
12:5013:30
14:10
14:50
15:3016:10
Tuesday, June 14th
Lecture Hall TFZ, 1st floor, Unit A
Biosensing for Molecular Diagnostics: Current Trends and Perspectives Maria MinnuniCoupling and monitoring chemical fluxes of microstructured enzyme layersGunther WittstockUltra-Sensitive System to Detect Minute Ionic Gradients within Glioma CellsPaulo RochaCoffeeSemiartificial Photosynthesis. How to Wire Photosystem 1 and 2 to ElectrodesWolfgang SchuhmannSelective and Reversible Ion-Detecting Sensor Elements in Aque-ous Environment Based on Organic Electronic DevicesEmil J.W. List-KratochvilLunch and PostersMechanical and optical sensing of biological systems using thin film electronicsIoannis KymissisBioelectronic Nose and Tongue: Integration of Human Receptors and Nano DevicesTai Hyun Park Electronic PlantsMagnus BerggrenClosing RemarksEnd (Lab Tour optional)
For automotive and building industry, storage and material handling techniques, steel with various metallic coatings is profiled. Additionally profiles are used as posts in soils, e.g. to carry photovoltaic modules or in viticulture, more general in fruit growing, to support plants under heavy fruit loads as well as against wind. Posts made of hot-dip galvanised steel are increasingly replacing wood based models.
Former investigations [1] on the influences of soil components and substances used in viticulture on the corrosion performance of hot-dip galvanised steel showed that corrosion in soils does not occur uniform-ly. It seemed to be higher at the lower end of the specimens.
To investigate this assumption, the thickness of the zinc layer was determined by XRF. Therefore the specimens were exposed to moist sand as well as to moist sand mixed with agriculturally used substan-ces, such as CuSO4 and NH4NO3. It was shown a lower thickness on the lower end of the specimens which may result from higher local corrosion rates or from additional oxidation due to macro-cell formati-on.
To clarify the existence of macro-cells and how they are located, a model post was developed which is able to carry self-made metal and reference electrodes. It can be driven into soils and electrodes can be located in different depths up to 1 meter which corresponds to real usage of posts. The potentials of each electrode (as a function of depth) and galvanic currents through the electrodes were determined using a multiplexer and an I/U - converter. With this setup, we were able to verify the existence of macro-cells.
[1] S. Ziebermayr, M. Fleischanderl, K.-H. Stellnberger, P. Linhardt, G. Mori, Corrosion resistance of hot-dip galvanised steel in soils, International Workshop “Biochemistry and more”, Wiener Neustadt, 2015.
CORROSION OF HOT-DIP GALVANISED STEEL IN SOILS – MACRO CELL FORMATION ON POSTS
S. Ziebermayr, Center of Electro-chemical Surface
Technology, Wiener Neustadt/
Austria
M. Fleischanderl, K.-H. Stellnberger,
voestalpine Stahl GmbH, Linz/Austria
P. Linhardt, Vienna University of
Technology, Vienna/Austria
G. Mori, Montanuniversitaet
Leoben, Leoben/Austria
For the understanding of corrosion mechanisms it is necessary to identify the resulting corrosion products. For this, reference data are required to allow a comparison with the data of the corroded sheets. The synthesis of these reference substances for corrosion products of zinc based coatings and the characterization by X-ray diffraction, infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy are the main part of this work. In order to ensure the equality of the synthetic products and the corrosion products on the corroded sheets the results of the measurements are compared with each other.
The names of these products are based on naturally occurring mine-rals. Therefore these minerals are characterized and their data are included in the comparison. The aim of this work is the synthesis of selected corrosion products of zinc based coatings and their analysis. The data obtained are checked whether they actually match the resulting compounds on corroded surfaces. Additionally, the naming of the products according to the naturally occurring minerals is proofed to be legitimated.
In this work zincite, smithsonite, hydrozincite, simonkolleite and layered double hydroxides (LDH) of zinc/aluminum and magnesium/aluminum as corrosions products were synthesized. The synthetic products’ identity could be confirmed by all characterization methods. Zincite, smithsonite, hydrozincite and Mg/Al LDH were synthesized as reference substances. The synthesis of simonkolleite and layered double hydroxides of zinc/aluminum has to be improved due to the contamination with zincite.
SYNTHESIS AND CHARACTERIZATION OF CORROSION PRODUCTS ON ZINC-BASED METALLIC COATINGS
B. Stallinger 1,
R. Steinberger 2,
G. Luckeneder 3,
K.-H. Stellnberger 3
and A. W. Hassel 1,4
1) Institute for Che-mical Technology of Inorganic Materials,
Linz/Austria
2) CDL-MS-MACH, Center for Surface
and Nanoanalytics, Linz/Austria
3) voestalpine Stahl GmbH, Linz/Austria
4) CEST Competence Centre for Electro-
chemical Surface Technology, Wiener
Neustadt/Austria
Background of the project is the clinical interest in research and surface modification of metallic biomaterials aiming prevention of biomaterial associated infections.
“Implant-related infections remain among the leading reasons for failure with, beside ethic aspects, causes high economic and social associated costs. According to the current knowledge, probably the most critical pathogenic event in the development of implant-related infection is biofilm formation, which starts immediately after bacterial adhesion on an implant and effectively protects the microorganisms from the immune system and systemic antibiotics. A rationale, modern prevention of biomaterial-associated infections should then specifi-cally focus on inhibition of both bacterial adhesion and biofilm formation [3].”
To exploit titanium materials with anticancer and antibacterial properties, TiO2 nanotubes arrays as nano-reservoirs for deposition of selenium were generated onto titanium substrates and then covered with chitosan layer. The deposition of selenium in TiO2 nanotubes was performed with electrodeposition [1]. The selenium deposited and chitosan-coated TiO2 nanotubes substrates (TiO2 nanotubes-Se-Chi) demonstrated great potential for promoting the proliferation of healthy osteoblasts and inhibiting the growth of cancerous osteoblasts. Meanwhile, the TiO2 nanotubes-Se-Chi substrates displayed a sustained release of selenium for 21 days.
Biomaterial-associated infection is a disastrous complication of modern orthopedic surgery that often leads to prolonged patient pain and functional losses.
To exploit titanium implants with long-term antibacterial property, TiO2 nanotubes were firstly generated onto titanium substrates via an anodization method, silver nanoparticles were then formed in situ within the TiO2 nanotubes and a quaternary ammonium salt (QAS,
ANTIBACTERIAL SURFACE MODIFICATION OF IMPLANT MATERIALS
J. Sun
CEST Competence Centre for Electro-
chemical Surface Technology, Wiener
Neustadt/Austria
3-trimethoxysily-propyldimethyloctadecyl-ammonium chloride) was immobilized onto TiO2 nanotubes [3]. The study presented a promising approach to fabricate antibacterial titanium-based implants for orthopedic application.
Bacteria have a highly successful and diversified strategy to adhere and survive on virtually all natural and synthetic surfaces. Surface charac-teristics of a biomaterial such as roughness, hydrophobicity, and electrostatic charge play only conditional roles, while a number of potential receptors for bacterial adhesive ligands are offered by the protein film that covers an implant immediately after its placement into the host body. Complement, albumin, and several other host proteins and lipids are the main components of this conditional protein film. The process of bacterial adhesion can be divided into a reversible phase, based on nonspecific interactions between implant surface and bacterial adhesions, and an irreversible phase, mediated by molecular and cellular interactions and closely associated with expression of biofilm-specific gene clusters in reversibly attached bacteria. All the process from bacterial adhesion to the production of a mature biofilm is extremely efficient and is normally completed within 12 to 18 h [4]. Evaluating the antibacterial activity of iodine-supported titanium (Ti–I2) and its impact on post-implant infection, as well as determining the potential suitability of Ti–I2 as a biomaterial. Ti–I2 clearly inhibited bacterial colonization more than the control metals [6]. Antibacterial coatings on titanium [7]: Formation of biofilms on titanium implants is a complex issue because of the diversity of bacterial ecosystems and so antibacterial coatings should be tailored to tackle different bacterial species in different environments. Antibacterial coatings have been traditionally designed to prevent initial adhesion of bacteria onto the implant surface without much attention to the mini-environment encountered after implantation. Many surface coatings such as adhesion-resistant coatings and coatings containing
or releasing antimicrobial agents shown in [7] are used to inhibit initial attachment of bacteria to titanium. One essential requirement is that it should not hamper tissue-integration and in fact, it will be better if the coating can benefit tissue integration.
[1] Fabrication of selenium-deposited and chitosan-coated titania nanotubes with anticancer and antibacterial properties, Xiuyong Chen, Kaiyong Cai∗, Jiajia Fang, Min Lai, Yanhua Hou, Jinghua Li, Zhong Luo, Yan Hu, Liling Tang, Colloids and Surfaces B: Biointerfaces 103 (2013) 149– 157[2] Antimicrobial peptides on calcium phosphate-coated titanium for the prevention of implant-associated infections, Xiuyong Chen, Kaiyong Cai∗, Jiajia Fang, Min Lai, Yanhua Hou, Jinghua Li, Zhong Luo, Yan Hu, Liling Tang, Colloids and Surfaces B: Biointerfaces 103 (2013) 149– 157[3] Dual action antibacterial TiO2 nanotubes incorporated with silver nanoparticles and coated with a quaternary ammonium salt (QAS), Xiuyong Chen, Kaiyong Cai ∗, Jiajia Fang, Min Lai, Jinghua Li, Yanhua Hou, Zhong Luo, Yan Hu, Liling Tang, Surface & Coatings Technology 216 (2013) 158–165[4] Antibacterial coating of implants in orthopaedics and trauma: a classification proposal in an evolving panorama, Carlo Luca Romanò1*, Sara Scarponi1, Enrico Gallazzi1, Delia Romanò1 and Lorenzo Drago2, Romanò et al. Journal of Orthopaedic Surgery and Research (2015) 10:157 DOI 10.1186/s13018-015-0294-5[5] Antibacterial Surface Treatment for Orthopaedic Implants, Jiri Gallo 1,*, Martin Holinka 1 and Calin S. Moucha 2, Int. J. Mol. Sci. 2014, 15, 13849-13880; doi: 10.3390/ijms150813849[6] Antibacterial iodine-supported titanium implants, T. Shirai a, T. Shimizu b, K. Ohta-ni b, Y. Zen c, M. Takaya d, H. Tsuchiya a,∗, Acta Biomaterialia 7 (2011) 1928–1933[7] Antibacterial Coatings on Titanium Implants, Lingzhou Zhao,1 Paul K. Chu,2 Yumei Zhang,1 Zhifen Wu1, Published online 27 July 2009 in Wiley InterScience (www.interscience.wiley.com). DOI: 10.1002/jbm.b.31463[8] Surface Coating and Modification of Metallic Biomaterials; Cuie Wen, e-book, 2015
Gabriela Schimo a,c
Wolfgang
Burgstaller b,c
and
Achim Walter
Hassel a,b,c
a CEST Competence Center for Electro-
chemical Surface Technology, Wiener
Neustadt, Austria
b Christian Doppler Laboratory for
Combinatorial Oxide Chemistry at the
Institute for Chemical Technology of Inor-
ganic Materials, Linz, Austria
c Institute for Che-mical Technology of Inorganic Materials,
Johannes Kepler Uni-versity Linz, Austria
Knowledge of the mobility of hydrogen within a metal is an essential aspect for determination of the hydrogen embrittlement susceptibility of the material. Generally, the hydrogen diffusion coefficient is a common measure to evaluate the hydrogen mobility within a material and is strongly influenced by the material’s microstructure: Metal lattice defects like grain boundaries, phase boundaries, inclusions etc. can act as traps for hydrogen causing a decrease of the apparent diffusion coefficient. Kelvin probe microscopy represents a novel technique allowing visualization of hydrogen within a metal by monito-ring its contact potential difference (CPD), which is lowered in the presence of hydrogen [1]. Different methods to determine the hydrogen diffusion coefficient based on the Kelvin probe technique are presented. As deformation drastically affects the microstructure, the influence of cold-rolling on the hydrogen mobility within a ferritic steel sheet was evaluated by performing a 2D analysis of hydrogen diffusion within a deformed sample [2]. Moreover, approaches to study hydrogen trapping and distinguish the apparent diffusion coefficient from the real, only diffusion related coefficient, are presented [3-5].
[1] Evers, S; Senöz, C; Rohwerder, M. Sci. Technol. Adv. Mater. 2013, 14, 014201.[2] Schimo, G.; Burgstaller, W.; Hassel, A.W., ISIJ Int. 2016, 56, 487.[3] Schimo, G.; Burgstaller, W.; Hassel, A.W., Electrochem. Commun. 2015, 60, 208.[4] Burgstaller, W.; Schimo, G.;Hassel, A.W., Int. J. Hydrogen Energy, revised version submitted.[5] Schimo, G.; Burgstaller, W.; Hassel, A.W., Int. J. Hydrogen Energy, revised version submitted.
SCANNING KELVIN PROBE BASED MEASUREMENT OF HYDROGEN MOBILITY WITHIN METALS
Christina Bliem,
Anca-Iulia Stoica
and
Christoph Kleber
CEST Centre of Elec-trochemical Surface
TechnologyViktor Kaplanstraße 22700 Wiener Neustadt
AustriaE-mail: christina.
Potentiometric methods have found many applications in clinical, industrial and environmental fields. Due to their low cost, ease of operation and short time of analysis, especially Ion-Selective Electro-des (ISE) have become widely used in practice [1]. Our studies are focused on the development of novel potentiometric sensors for the selective quantification of serotonin in complex media like urine. Therefore, Ion-Selective Electrodes based on plasticized PVC membra-nes are applied. The electroactive part of the membrane consists of an ion pair complex formed between the protonated analyte and a carborane anion [Co(1,2-C2B9H11)2]− [2]. The structure of the complex was analysed by NMR, FT-IR and MALDI-TOF. The Ion-Selective Electrodes were optimized with respect to the type of plasticizer, as well as the membrane thickness and its composition. The perfor-mance of the developed sensors was studied regarding response time, lifetime, slope value, concentration range, limit of detection and selectivity. The results obtained clearly demonstrate the potential of the novel electrodes for a further development of efficient and simple miniaturized sensors to be applied in pharmaceutical and clinical daily routine for the determination of neurotransmitters.
[1] Mikhelson, K.N., Ion-Selective Electrodes. Vol. 81. 2013, Berlin: Springer.[2] Bliem, C., et al., Development of selective membrane sensors for the determinati-on of serotonin in clinical samples. Paper presented at Eurocorr. 2015. Graz.
DEVELOPMENT OF SELECTIVE MEMBRANE SENSORS FOR THE DETERMINATION OF SEROTONIN IN CLINICAL SAMPLES
G. Hölzl
CEST Centre of Electrochemical
Surface Technology
Plenty of researchers have investigated the corrosion of zinc in the past century. A lot of the important parameters influencing this process have already been revealed. It has become common knowledge that atmos-pheric pollution, road/marine salts, temperature as well as relative humidity are crucial parameters affecting the corrosion behavior of metals. Analytical methods are steadily improved and new ones are developed. By the right choice of instruments it is possible to get even deeper insights in already known corrosion processes.
In the present studies we investigated the NaCl particle induced corrosion on electrolytically zinc coated steel samples in its early stages. We used a combination of light microscopy and Raman spectro-scopy. Studies were conducted in a simple
3D-printed weathering cell. It was shown that these two measurement methods synergize very well. Light microscopy is useful for getting a rough overview about the different corrosion stages and areas. Raman spectroscopy was applied for the in situ characterization of the corrosion products thereby avoiding product conversions. The big advantages of Raman spectroscopy are its high lateral resolution below 2 µm and its insensitivity to water layers or droplets which are espe-cially useful for salt particle induced corrosion studies.
It was demonstrated that Raman spectroscopy and light microscopy are indeed a perfect combination for in situ early stage corrosion studies. We were able to get mechanistic insights in the process of NaCl particle induced corrosion. Interesting product conversions were observed upon drying of the sample surface.
RAMAN SPECTROSCOPY AND LIGHT MICROSCOPY – A COMBINATORIAL APPROACH FOR EARLY STAGE CORROSION STUDIES
A. Sikora
CEST Centre of Electrochemical
Surface Technology
High-temperature cyclic voltammetry (HT-CV) has commonly been used as a method for determining thermodynamic data such as Gibb’s energy of oxide formation or equilibrium potentials of electrode reactions and kinetic data. While thermodynamic information is derived from particular potentials, kinetic information is extracted from current densities.
Gaining some of these data however is beneficial for cataloguing various alloys according to formation of adherent oxide scales for effective protection of the bulk material under specific atmospheric conditions above 500°C. But it is more than difficult to apply the appropriate conditions around the sample to be investigated. While temperature setting is more or less an easy undertake, partial pressure of O2, contamination in the atmosphere like SO2 and corrosion-promoting substances such as KCl or NaCl are not quantifi-able and further not adjustable. The existing cell setup does not meet these requirements at all so that a new cell setup has been developed. The conventional cell setup is depicted in Figure 1, whereas the new cell setup is shown in Figure 2 below.
Figure 1: Schematic cross-sectional
view of conventional cell setup
Figure 2: Schematic cross-sectional
view of new cell setup
‘BIOELECTROCHEMISTRY AND MORE’DEVELOPMENT OF A NEW CELL SETUP FOR HT-CV MEASUREMENTS
One of the major assets of the new cell setup in comparison to the conventional one is the sealing of the sample. The oxygen partial pressure in the confined space at working electrode (WE), where the sample is being situated, can be adjusted by polarisation, while the platinum-plate at the reference electrode (RE) is still in normal atmosphere. Hence, calibration measurements for RE with Cu or any other suitable material become no longer necessary. Further asset is the adjustment of other atmospheric composition through additives, if required.
While the current-voltage curves of the conventional cell setup show primarily thermodynamics of different oxidation states of the material to be investigated , the curves of the new cell setup reveals more about kinetics of a specific redox reaction. In case of the redox reaction Cu+ ∗ Cu2+ + e-, the linear part around the redox potential has been used to determine polarisation resistance at certain temperatures and further the activation energy by means of an Arrhenius plot. This information is valuable to describe the behaviour of a specific material in forming protective oxide layers more precisely.
1 J.Oeijerholm, G.Fafilek, J.Pan, Electrochemical and Solid-State Letters, 10 (6) C47-C50 (2007).1 G.Fafilek, S.Harasek, Solid State Ionics 119 (1999) 91-96.
The prehistoric beginnings of adhesive bonding last back over 200 000 years. Birch tar was a common adhesive for tools, weapons and ships. Until the age of industrialisation, only adhesives available from nature were used. Then, a variety of synthetic adhesives were developed which found manifold applications. In modern body manufacturing epoxy resins, polyu-rethane- and rubber-based adhesives are used for joining the chassis parts. Excellent adhesion and corrosions resistance properties are sought after.
To ensure the corrosion resistance of steel hot-dip galvanizing is commonly employed, whereby different zinc alloys are used. Next to use pure zinc coatings, with small amounts of aluminium, a trend emerged in the 2000s to use alloys with 1-3% Aluminium and 1-3% Mag-nesium. These Zn-Mg-Al coatings benefit from superior corrosi-on resistance and improved formability with lower coating thicknesses. However, some commercial adhesives have difficulties to bond on these Zn-Mg-Al surfaces. Thus, it is crucial to understand the interactions between the adhesive and the oxide surfaces for further designing and optimizing adhesive bonding on Zn-Mg-Al.
Figure 1. Schematic of the different layers in an adhesive bond between Zn-Mg-Al hot-dip galvanized steel. The surface consists of manifold oxides, hydroxides and carbonates which form different types of interaction with the adhesive. The impact of corrosion on the adhesive and formed interface to the oxide layer are investigated.This work reviews the relevant adhesion mechanisms and properties of Zn-Mg-Al surfaces. The adhesion and delamination properties of epoxy adhesives are investigated as a function of the surface chemistry. Therefore, surface modification and different analytical techniques like IRRAS, EIS, SEM, XRD, XPS, AFM, and AES in combination with different corrosion tests are employed. These investigations will help to further form mechanistic models for the interactions during curing and corrosion in the interface between adhesive and Zn-Mg-Al sur-face as well as oxide surfaces in general.
SURFACE CHEMISTRY, ADHESION- AND DELAMINATION OF ADHESIVES ON ZN-AL-MG HOT-DIP GALVANISED STEEL
M. Nadlinger
CEST Centre of Electrochemical
Surface Technology
DEVELOPMENT OF AN IMMUNOSENSOR PLATFORM FOR THE DETECTION OF WATER CONTAMINANTS
Mayerhuber Lisa,
Fruhmann Philipp,
Bliem Christina,
and
Kleber Christoph
CEST Competence Center for Electro-
chemical Surface Technology, Wiener
Neustadt, Austria
European maritime regions account for over 40% of the EU gross national product (GNP) and Europe’s coastal zone is estimated to have an equivalent value of €18 billion/annum [1]. Considering this, the chemical contamination of estuarine and coastal areas is a highly complex issue with negative implications for the environment, human health (through the food chain) and related coastal industries such as fisheries. In order to provide a tool for the monitoring and protection of this sensitive system we and our partners [1] are aiming for the develop-ment of a miniaturized, remote and autonomous immunosensor platform based on an array of electrodes and a microfluidic system in a lab-on-a-chip configuration with electrochemical detection. For this reason optimized antibodies [2] were produced for a series of analytes and used for the development of a measurement protocol. The detec-tion is based on a competitive immunoassay [3] using HRP labelled secondary antibodies and 3.3∗,5.5∗-Tetramethylbenzidine as substrate for the signal generation. Measurement results for our antibodies showed a good limit of detection (depending on the analyte) ranging down to the pico-molar range. Beside the presentation of our protocol and measurement results, the design of the whole sensor platform will be presented.
Figure 1: Calibration of Irgarol
[1] http://sea-on-a-chip.eu[2] Ballesteros, et al., Anal. Chem., 1998, 70, 4004-4014[3] Sample Handling and Trace Analysis of Pollutants, Techniques and Quality Assurance, Editor: Damia Barcelo, ISBN: 9780444828316
Self-assembled colloidal nanoparticles is of paramount relevance for opening new research frontiers in nanoscience and nanotechnology for a wide range of biological and chemical systems.1
Recent progress has been made in developing nature-inspired strategies for the synthesis of self-associated hybrid particles combining organic, bio and inorganic components.2
The synthetic efforts have been focused on the creation of functional structures that combine not only properties of the individual compo-nents but also exploit the interactions between constituting particles in a synergetic manner.3
Progress in this field aims to systems with increased complexity where specific functionalities can be introduced and displayed in a simple but efficient fashion. To perform specific functions, use of proteins, or more precisely: enzymes, as building blocks is an attractive approach owing to their inherent structural and chemical properties.4
Yet, it is still a challenging task to create protein-based programmable suprastructures with controlled size uniformity and composition by simple harnessing these interactions. In this work, we demonstrate that under specific conditions, the assembly between a ligand-binding protein (Concanavalin A, Con A) and a ligand-presenting enzyme (Glucose oxidase, GOx) proceeds through a self-limited growth process.5
The balance between attractive and repulsive interactions leads to bionanoparticles (BNPs) with defined size and composition. The as-synthesized BNPs retain the enzymatic activity and exhibited enhanced ligand-binding affinity. Moreover, the supraparticles were successfully assembled on gold surfaces functionalized with mannose residues. Then, multilayer interfacial architectures were constructed by sequential assembly of biosupraparticles and concanavalin A on
E. Piccinini a,
D. Pallarola a,
F. Battaglini b
and
O. Azzaroni a
a Instituto de Inves-tigaciones Fisico-
químicas Teóricas y Aplicadas (INIFTA),
Universidad Nacional de La Plata, CONICET,
La Plata, Argentina.
b Instituto de Química Física de los Materi-
ales, Medio Ambiente y Energía (INQUI-
MAE), Buenos Aires, Argentina.
E-mail: [email protected]
RECOGNITION-DRIVEN ASSEMBLY OF SELF-LIMITING PROTEIN SUPRAPARTICLES DISPLAYING ENZYMATIC ACTIVITY
electrode surfaces. These results suggest that the biocolloids act as ambivalent recognition particles, which bind both to mannose and concanavalin A with high affinity.
[1] B. Pelaz, S. Jaber, D. J. De Aberasturi, V. Wulf, T. Aida, J. M. De La Fuente, J. Feldmann, H. E. Gaub, L. Josephson, C. R. Kagan, N. Kotov, L. M. Liz-Marzán, H. Mattoussi, P. Mulvaney, C. B. Murray, A. L. Rogach, P. S. Weiss, I. Willner and W. J. Parak, ACS Nano, 2012, 6, 8468–8483.[2] E. Piccinini, D. Pallarola, F. Battaglini, O. Azzaroni, Mol. Syst. Des. Eng., 2016.[3] J. Il Park, T. D. Nguyen, G. de Queirós Silveira, J. H. Bahng, S. Srivastava, G. Zhao, K. Sun, P. Zhang, S. C. Glotzer and N. Kotov, Nat. Commun., 2014, 5, 3593.[4] K. Ariga, Q. Ji, T. Mori, M. Naito, Y. Yamauchi, H. Abe and J. P. Hill, Chem. Soc. Rev., 2013, 42, 6322–6345.[5] E. Piccinini, D. Pallarola, F. Battaglini and O. Azzaroni, Chem. Commun., 2015, 51, 14754–14757.
One of the greatest potentials of organic electronics is the realization of miniaturized, or even implanted, biosensors as low-cost point-of-care devices, capable of label-free, selective detection of analytes (e.g. biomarkers, pathogens) while creating an electronic read out for user friendly interaction.
The basic working principle of these sensors is based on a standard OFET configuration. An OFET-biosensor is an analytical device consisting of an OFET endowed with covalently attached biological recognition units to the OSC, whose specific interactions with analytes changes the electrical current flowing between source and drain.
Since the sensitivity of such a sensor is dependent on the thickness of the semiconductor, or more precisely the distance between the analytes’ electrostatic interactions and the charge carrying layer, the maximum sensitivity would be achieved in a device consisting of only one monolayer of the active material, because charges in OFETs are confined only to one monolayer. Such devices called self-assembled monolayer field-effect transistors (SAMFETs) are the topic of this work. We developed a novel building block like approach towards SAMFETs using click chemistry.
The resulting devices, named CLICK-FETs, were extensively characte-rized and benchmarked against conventional SAMFET devices. The key advantage of the presented concept is its facile modular approach and the possibility of post-modification of OSC, thus allowing the endow-ment of bio recognitions units, which are perquisites for enabling label-free selective and specific detection of biomarkers and patho-gens.
Johannes
Bintinger [a*],
Nathan Cernetic [b],
Roland Bittner [a],
Markus Sauer [c],
Annette
Folske-Schmitz [c],
Markus Holzweber
[d],
Theanne Schiros
[e,f],
Dennis Nordlund [g],
Dennis Svatunek [a],
Hong Ma [b],
Helmuth Hoffmann
[a],
Johannes Fröhlich
[a],
Alex Jen [b],
Hannes Mikula [a]
[a] Institute of Applied Synthetic Chemistry, Vienna University of Technology, Getrei-
demarkt 9/163, 1060 Vienna, Austria
[b] Department of Materials Science
and Engineering, Box 352120, University of Washington, Seattle,
WA 98195-2120, Seattle, USA
[c] Analytical Inst-rumentation Center, Vienna University of
Technology, Getreide-markt 9, 1060 Vienna,
Austria
USING CLICK CHEMISTRY FOR A FACILE APPROACH TOWARDS SELF-ASSEMBLED MONOLAYER FIELD-EFFECT TRANSISTORS (SAMFETS): A NEW VERSATILE APPROACH FOR SENSING APPLICATIONS
[d] Institute of Chemical Technologies and Analytics, Vienna University of Technology, Getreidemarkt 9, 1060
Vienna, Austria
[e] Fashion Institute of Technology, State University of New York, 227 W
27th St, NY 10001, USA
[f] Center for Precision Assembly of Superstratic and Superatomic Solids,
MRSEC, 530 W. 120th St., Columbia University, NY, USA
[g] Stanford Synchrotron Radiation Lightsource, SLAC National Acce-lerator Laboratory, 2575 Sand Hill
Road, Menlo Park, CA, USA
Hybrid mesoporous architectures merging the properties of inorganic materials and macromolecular building blocks have found an incredi-ble resonance and attracted widespread interest as a fundamental and technological challenge to chemists, physicists and engineers during the past decade. Part of the appeal of hybrid mesoporous materials is the unique and thorough molecular control of their intrinsic topologi-cal and chemical characteristics that self-assembly techniques and nanochemistry are able to provide. With the correct choice of building blocks and self-assembly conditions, it is possible to produce nanos-tructured materials via sol–gel processes with precisely defined and tunable chemical functions incorporated into well-defined ordered mesostructured frameworks; this translates into a corresponding fine control in the way such building blocks define chemistry and topology across different length scales. This approach leads to the construction of hierarchical nanosystems with unprecedented control over functio-nal positioning using soft chemistry methods – in a similar way to what nature does. Within this framework we have described the creation of hybrid polymer-inorganic assemblies in which the polyme-ric and inorganic domains work synergistically to control the ionic transport properties of the hybrid platform.
Sebastián Alberti 1*,
Galo Soler-Illia 2
and
Omar Azzaroni 1
1 Instituto de Inves-tigaciones Fisico-
químicas Teóricas y Aplicadas (INIFTA),
Universidad Nacional de La Plata, CONICET,
Argentina
2 Universidad Nacional de Gral.
San Martín (UNSAM), Argentina
*email: [email protected]
MANIPULATION OF MOLECULAR TRANSPORT INTO MESOPOROUS THIN FILMS THROUGH THE INTEGRATION OF POLYELECTROLYTE BRUSHES
Jan Hrbac,
Libuse Trnkova
Department of Chemistry, Faculty
of Science, Masaryk University, Kamenice 5, CZ – 625 00 Brno,
Czech Republic; E-mails:
[email protected]; [email protected]
The deposition of nanostructured layers onto conductive and/or semiconductive substrates is a current research topic within the fabrication of modified surfaces on solid electrodes for specific applications. Electrodes modified by nanomaterials constitute a platform to improve the sensing and acquisition of structure-functional information on not only a wide range of low molecular weight biomole-cules but also substances such as nucleic acids, proteins, and polysac-charides related to diseases and health problems. The presented research focuses on the development of metallic and metal oxide nanostructured surfaces, allowing the construction of highly sensitive electrochemical and also surface enhanced Raman scattering (SERS) sensors. Our contribution to this field comprises nontraditional electrode modification methods. The first technique, electrochemical/electrophoretic deposition, relies on in situ formation of metal oxides/hydroxides via the anodization of metal in an unsupported medium, e.g., ultrapure water [1].
The formed oxide/hydroxide dispersions are in equilibrium with free metal cations, which can be reduced on a suitable conductive or semiconductive substrate in the form of nanostructured deposits. The second approach, suitable for the modification of single use substrates such as screen printed electrodes and carbon fiber microelectrodes, is based on applying DC electrical discharges between a source metal electrode and a target substrate electrode [2].
The third technique then exploits metal plating in the presence of porous membrane templates (e.g., an aluminium oxide structure). The nanostructure types (nanorods, nanofibres, and nanowires) depend on both the pore dimensions and the conditions during the spreading and electrodeposition of the nanomaterial onto the electrode surface [3].
Porous silicon is a semiconductive porous electrode; the electrochemi-cal deposition of metals occurs at the bottom, on the walls, and in the openings of the pores. The size and distribution of the nanostructures are given by the material (pores’) properties and the quantity and
NONTRADITIONAL APPROACHES TO ELECTRODE MODIFICATION BY NANOMATERIALS FOR BIOSENSING
quality of the metal used for plating. Electrochemical deposition on porous silicon is influenced by illumination conditions. The results achieved via the aforementioned methods indicate that new, extremely simple and ultra-low-cost procedures were developed to prepare nanomaterial-modified electrodes sensitive to diverse bioanalytes.
[1] V. Halouzka, P. Jakubec, L. Kvitek, V. Likodimos, A. Kontos, K. Papadopoulos, P. Falaras, J. Hrbac, J. Electrochem.Soc., 160 (2013) E54-E59.[2] D. Riman, A. Avgeropoulos, J. Hrbac, M. Prodromidis, Electrochim. Acta 165 (2015) 410-415.[3]K. Klosova, N. Serrano, O. Salyk, L. Trnkova, Current Nanoscience , 7 (2011) 1573-4137.
Recent studies of molybdenum oxides and molybdate compounds showed that this class of materials has great potential for being used as antibacterial agents [1,2]. In the same time, Ag and Cu compounds are known as bactericidal [3], whereas CaOH is traditionally used in endodontic treatment against infections [4]. Based on these premises, different molybdate powders (Ag2MoO4, CuMoO4, Cu3Mo2O9 and CaMoO4) were produced via chemical synthesis using non-harsh conditions and in the range of temperatures from room temperature up to 100 °C, and for selected samples post-synthesis heat treatments were performed. Their crystallographic characterization revealed the presence of fully crystalline phases with no spurious compounds. Morphological investigations showed grain sizes ranging from nanome-ter (Cu3Mo2O9) to micrometer (Ag2MoO4, CaMoO4 and CuMoO4). The suspensions of synthesized powders with different concentrations (1, 5 and 10 mM) were tested for antibacterial activity against transformed E. coli BL21DE3 (kanamycin resistant) by mixing them with the bacterial culture and spreading them onto agar plates with nutrient medium. Optical density measurements of the suspensions, as well the observation of colonies grown on the agar plates after defined times showed extremely high antibacterial activity in the presence of some of the tested molybdates (Ag2MoO4, Cu3Mo2O9 and CuMoO4), whereas CaMoO4 did not inhibit the growth of E. coli.
Acknowledgements The financial support by the Austrian Federal Ministry of Economy, Family and Youth and the National Foundation for Research, Technology and Development for the Christian Doppler Laboratory for Combinatori-al Oxide Chemistry (COMBOX) is gratefully acknowledged.
[1] C. C. Mardare, A. W. Hassel, ACS Comb. Sci. 2014, 6, 631[2] C. C. Mardare, D. Tanasic, A. Rathner, N. Müller, A. W. Hassel, Phys. Status Solidi A 2016, DOI 10.1002/pssa.201532786[3] S. M. Dizaj, F. Lotfipour, M. Barzegar-Jalali, et al., Mater. Sci. Eng. C 2014, 44, 278[4] J. F. Siqueira, H. P. Lopes, Int. Endod. J. 1999, 32, 361
SYNTHESIS, CHARACTERIZATION AND ANTIBACTERIAL PROPERTIES OF DIFFERENT MOLYBDATE POWDERS
C. C. Mardare a,
D. Tanasic b,
J. P. Kollender b,
A. Rathner c,
P. Rathner c,
N. Müller c,
A. W. Hassel a,b,d
a Christian Doppler Laboratory for
Combinatorial Oxide Chemistry at Institute
for Chemical Tech-nology of Inorganic
Materials, JKU Linz, Austria
b Institute for Che-mical Technology of Inorganic Materials,
JKU Linz, Austria
c Institute of Organic Chemistry, JKU Linz,
Austria
d CEST Competence Center for Electro-
chemical Surface Technology, Viktor Kaplan Str. 2, 2700
Wiener Neustadt, Austria
We demonstrate the measurements of hormones and endocrine disrupting compounds (EDC) with immobilized ssDNA aptamers on a graphene surface. The use of graphene yields a high sensitive and selective sensor platform. The aptamers, purified with a SELEX process, are immobilized on a graphene surface for electrically and optically determination of target ligand's concentrations. A Graphene Field-effect transistor varies its current IDS according to the ligand's concentration in solution. The refractive index of the gold/graphene surface changes due to the aptamers binding events, measured simultaneously with SPR and is used to verify the electrical measure-ment.
Patrik Aspermair (a,b)
Supervisor:
Wolfgang Knoll (a),
Sabine Szunerits (b)
(a): Austrian Institute of Technology, Biosensors
department - AIT
(b): L'Institut d'électronique, de
microélectronique et de nanotechnologie - IEMN
APTAMER SENSOR FOR SMALL ANALYTES BASED ON GRAPHENE FETS AND PLASMON OPTICS
A. Geiss
AIT Austrian Institute of Technology GmbH
Membrane proteins are a common target in disease treatment as well as they are subject of controversial discussions in basic research. The necessity of an intact membrane is mostly fulfilled by liposomes, whole cells or compartments thereof. To overcome consequential problems – like the random protein orientation in liposomes or the influence of non-target proteins in case of entire cell or organelle membranes – we have developed proteo-lipobeads, acting as a low-cost and easy-to-use kind of artificial membrane system.
PROTEO-LIPOBEADS: A NEW PLATFORM FOR THE INVESTIGATION OF MEMBRANE PROTEINS
Coil coated steel can be used for a multitude of a various field of applications such as corrosion protection. That led to and the usage of oil coatings becoming an important technique in industry. As organic coating are typically cross-linked polymers such as polyester polyure-thane, are used because the providing of their good barrier properties. These polymers should provide protecting of the steel from corrosion due to their ability to resist the permeation of water. Thus, characteri-ze diffusion and effusion of water in and out of the coating is an important task to evaluate the quality of the coating with respect to its thermomechanical properties.
Raman spectroscopy in combination with Electrical Impedance Spectroscopy (EIS) has been used to monitor water diffusion into the coating in dependence on the temperature and the storage time in an aqueous system. Cyclic experiments are performed to test if the development of water channels within the coating can be observed. The results of these experiments will be correlated to cantilever beam tests performed in a climatic chamber which allows the determination of the glass transition state (Tg) by fixing the humidity at e.g. 50 % and changing the temperature in a range from 70 to 0 °C. Additionally, by fixing the temperature and performing a “humidity jump” one can estimate the humidity dependence of the glass transition range. Urspr. Text paper
Coil coating is an important technique in construction industry. The polymeric binder determines the coating`s properties which can be used for a multitude of a various field of applications. A very parame-ter concerning the quality of a coating is is its barrier properties, which means its resistance to water permeation. To analyze the coating`s ability to protect the substrate from corrosion, Raman spectroscopy as well as Impedance spectroscopy (EIS) has been used. Additionally the visualization of the developing water channels has been tested as well as its dependency on the temperature and the storage time in an aqueous system
Franziska
Rosensteiner
CEST Competence Cen-ter for Electrochemical
Surface Technology, Wiener Neustadt
ANALYZING THE BARRIER PROPERTIES OF ORGANIC COATINGS ON STEEL USING RAMAN SPECTROSCOPY, ELECTRICAL IMPEDANCE SPECTROSCOPY AND A CLIMATIC CHAMBER
Luisa Torsi
Dipartimento di Chimica
Università degli Studi di Bari “Aldo Moro”,
Via Orabona 4I – 70126 Bari, Italy
E-mail: [email protected]
Printable and organic bioelectronic is a highly interdisciplinary re-search field that aims at the development of key-technologies to investigate biointerfaces as well as to face novel challenges in life-science and medicine. It currently encompasses, besides biosensors, many other different applications, including neural interfaces, tissue engineering and drug delivery. It is a powerful tool that exploits the direct interfacing of a field-effect transistor (FET) with functioning or even living bio-systems. These systems can be used to investigate fundamental aspects of bio-chemical interactions and exploit this knowledge to realize ultra-sensitive biological and chemical sensor.
ORGANIC BIO-ELECTRONIC SENSORS FOR ULTRA-SENSITIVE DETECTION
In all living systems biological channels work as nanodevices in charge of regulating key functions as electric potential, ionic flow, and molecular transport across the boundaries of the cells. Along these lines, the virtues of working with nanofluidic elements are being increasingly recognized by the biomimetics research community. This has led to the emergence of a research area that is currently at the forefront ofmaterials science and engineering. The advent of track-etching techniques has resulted in an increasing mastery in construction of nanoscale fluidic structures and has given a decisive impetus not only to the development of this exciting area of nanotechnology but also opened up new possibilities to reproducibly engineer nanopore and nanochannel architectures with various shapes and diameters down to a few nanometers. One major attraction of these nanofluidic elements is their outstanding ability to control and manipulate the transport of chemical and biochemical species flowing through them, thus enabling the construction of ionic circuits capable of sensing, swit-ching, or separating diverse species in aqueous solutions. Furthermo-re, these nanofluidic devices have also been shown to display trans-port properties that resemble biological protein ion channels, such as ion selectivity, current rectification, flux inhibition by protons and divalent cations, transport of ions against concentration gradients, and even ion current fluctuations. In the particular case of asymmetric nanochannels/nanopores, appealing rectification effects arise when the channel surface is charged and the dimensions are comparable to the Debye length. These fascinating physicochemical properties displayed by charged nanochannels or nanopores provided the scenario to create new functional and addressable nanofluidic architectures and also led to the birth of a whole new area of research concerning the design of nanochannel-based devices resting on surface charge governed ionic transport.
In this presentation we will show that the incorporation of adaptive and responsive soft materials into robust nanofluidic channels provides new opportunities to transduce biological, chemical and physical stimuli into easily measurable and processable ionic signals.Interfacing with the Brain Using Organic Electronics
BIOMIMETIC INTEGRATED NANOSYSTEMS BASED ON SOLID-STATE NANOPORES: NANOFLUIDIC-ENABLED “IONTRONIC” TRANSDUCTION OF BIOLOGICAL, CHEMICAL AND PHYSICAL STIMULI
Omar Azzaroni
Instituto de Investiga-ciones Fisicoquímicas
Teóricas y Aplicadas (INIFTA)
Universidad Nacional de La Plata – CONICET –
ArgentinaE-mail: azzaroni@inifta.
unlp.edu.ar
INTERFACING WITH THE BRAIN USING ORGANIC ELECTRONICS
George Malliaras
Department of Bioelectronics
Ecole des Mines de St. Etienne, FranceE-mail: malliaras@
emse.fr
One of the most important scientific and technological frontiers of our time lies in the interface between electronics and the human brain. Interfacing the most advanced human engineering endeavor with nature’s most refined creation promises to help elucidate aspects of the brain’s working mechanism and deliver new tools for diagnosis and treatment of a host of pathologies including epilepsy and Parkinson’s disease. It also represents a unique opportunity for industry: Medical electronics is the fastest-growing segment of the semiconductor industry. Current solutions, however, are limited by the materials that are brought in contact with the tissue and transduce signals across the biotic/abiotic interface. The field of organic electronics has made available materials with a unique combination of attractive properties, including mechanical flexibility, mixed ionic/electronic conduction, enhanced biocompatibility, and capability for drug delivery. I will present examples of organic-based devices for recording and stimulati-on of brain activity, highlighting the connection between materials properties and device performance. I will show that organic electronic materials provide unparalleled opportunities to design devices that improve our understanding of brain physiology and pathology, and can be used to deliver new therapies. I will focus on the mechanism of operation of these devices, trying to draw parallels between the languages of solid state physics and of electrochemistry.
The interaction of biological systems with artificial and natural materials plays an important role in many disciplines, ranging from medical implants to biomolecular nanotechnology. Understanding and ultimately controlling the processes and reactions at these biointer-faces requires a complementary interface science approach that takes into account the complexity of the interfaces resulting from the adsorption of organic molecules and macromolecules. Combined studies by means of Atomic Force Microscopy, quartz crystal microba-lance and optical spectroscopy allow for an advanced understanding of structures and processes at electrolyte/solid interfaces and of the molecular organization of biological nanomaterials. The presentation provides an overview on the basics of the analytical approach and their application to different systems, such as bioresorbable materials or surface catalyzed assembly of amyloid polypeptides.
Guido Grundmeier,
Adrian Keller
Technical and Macro-molecular Chemistry,
University of PaderbornPaderborn, Germany
E-mail: [email protected]
ANALYSIS OF MOLECULES AND MACROMOLECULES AT ELECTROLYTE/SOLID INTERFACES – INTERFACE CHEMISTRY, SELF-ORGANIZATION AND INTERFACIAL FORCES
Lewis Rothberg
Department of Chemistry
University of Ro-chester
E-mail: [email protected]
We have developed a very simple and sensitive method to detect adsorption of unlabeled target molecules surfaces at levels much less than a single monolayer (attomoles of typical materials) by measuring surface reflectivity from silicon wafers that have been functionalized with molecular probes capable of target selective binding. [1]. Because the technique takes advantage of interference caused by opposite phase shifts for reflections above and below the Brewster angles for two interfaces, we have called the method Brewster Angle Straddle Interferometry (BASI). Detailed theoretical comparison with surface plasmon resonance (SPR) shows that BASI is relatively insensitive to probe wavelength, temperature and angle of incidence. These provide practical advantages for implementing very simple point of care diagnostic assays. In addition, BASI should be especially advantaged relative to SPR imaging for reading of microarrays to implement massively parallel binding kinetics assays. We will compare the observed sensitivity with theoretical predictions and argue that continued improvement of RI should make it superior to SPR, especially for imaging applications. Examples of DNA and protein detection will be presented along with a discussion of some of the chemical challenges needed to make BASI practical for commercial applications.
DETECTION OF UNLABELED BIOMOLECULES USING SIMPLIFIED REFLECTIVE INTERFEROMETRY
The rising health awareness among the population on the one hand and the cost pressure on health systems in particular as a result of demographic changes in the coming years, on the other hand, require appropriate methods that enable a change of the health system away from pure disease management and repair medicine toward health maintenance and prevention. In this context, new biosensing technolo-gies for highly sensitive and quantitative rapid near-patient molecular testing will play a pivotal role.
Among the different transduction principles in biosensing, electroche-mical detection appears to be one of the most promising candidates to fulfill the demanding requirements given in point-of-care (POC) diagnostics. Since user friendliness is of paramount importance we have a particular focus on saliva, which presents the ideal sample fluid for non-invasive point-of-care testing. Concentration levels of target biomarker molecules in saliva can be up to three orders of magnitude lower than in serum. Therefore, highly sensitive detection methods are required.
With respect to nucleic acid detection, we are pursuing detection methods that make use of isothermal amplification techniques. One approach relates to real-time monitoring of the electrical conductivity in the amplification-mix via impedance spectroscopy. Another ap-proach targets end point detection employing methylene blue as intercalating redox reporter.
With respect to immunosensors we are working on electrochemical detection schemes using enzymatic amplification and redox-cycling mechanisms that are suited for integration in lateral flow platforms.Regarding the technological implementation of the different biosensor systems, we are striving for environmentally friendly, resource-saving, and cost-effective concepts. To this end we are investigating paper based sensor platforms and ink jet printing as a means for realizing miniaturized sensing elements requiring only minute amounts of material.
Martin Weber
Molecular Diagnostics, Health & Environment
DepartmentAIT Austrian Institute of
Technology GmbHDonau-City-Straße 11220 Vienna, Austria
E-mail: [email protected]
ELECTROCHEMICAL BIOSENSOR SYSTEMS FOR POC DIAGNOSTICS
In nature, charge recombination in light-harvesting reaction centers is minimized by efficient charge separation. In this presentation we show a first attempt to biomimic this by coupling dye-sensitized TiO2 nanocrystals to a decaheme proteins, MtrC and OmcA from Shewanel-la oneidensis MR-1, where the ten hemes of MtrC or OmcA form a ~7 nm long molecular wire between the TiO2 and the underlying electro-de. The system is assembled by forming a densely-packed protein film on an ultra-flat gold electrode, followed by the adsorption of ~7 nm sized TiO2 nanocrystals that are modified with a phosphonated bipyridine Ru(II) dye (RuP). The step-by-step construction of the decaheme/TiO2 systems are monitored with (photo)electrochemistry, quartz-crystal microbalance with dissipation (QCM-D) and atomic force microscopy (AFM). Photocurrents are dependent on the redox state of the MtrC or OmcA, confirming that electrons are transferred from the TiO2 nanocrystals to the surface via the MtrC conduit. In other words, the TiO2 and decaheme molecular wires function as hybrid photodiodes in which MtrC or OmcA traps the conduction-band electrons from TiO2 before transferring them to the electrode. To the best of our knowledge, this report is the first demonstration of a photobioelectrochemical system that uses a redox protein to mimic efficient charge separation found in biological photosystems.
Lars J. C. Jeuken,
Ee Taek Hwang,
Khizar Sheikh,
Katherine L. Orchard,
Daisuke Hojo,
Valentin Radu,
Chong-Yong Lee,
Emma Ainsworth,
Colin Lockwood,
Manuela A. Gross,
Tadafumi Adschiri,
Erwin Reisner,
Julea N. Butt
School of Biomedical Sciences and the Astbury
Centre
University of Leeds, Leeds LS2 9JT, United Kingdom
Department of Chemistry University of Cambridge
Lensfield Road, Cambridge CB2 1EW, United Kingdom
Advanced Institute for Materials Research
Tohoku University, 2-1-1 Katahira Aoba-ku
Sendai, Miyagi, 980-8577, Japan
Centre for Molecular and Structural Biochemistry
School of Chemistry, and School of Biological
Sciences
University of East Anglia, Norwich Research Park
Norwich NR4 7TJ, United Kingdom
E-mail: [email protected]
A DECAHEME CYTOCHROME AS A MOLECULAR ELECTRON CONDUIT IN DYE-SENSITIZED PHOTOANODES
Molecular diagnostics is defined as the use of biological markers, to test for specific states of health or diseases, possibly their progressi-on, as well as the assessing of the risk of their development by a prognostic molecular profiling. Molecular diagnostics may eventually aid to finalize the best therapy for a given individual patient, that is, the ability to provide tailored therapies through the analysis of the patient’s molecular specificity related to its disease.
Biosensing represents at present an interesting tool for applications to molecular diagnostics. In particular, in the past years, many attempts have been devoted to apply different label-free transduction principles such as conventional surface plasmon resonance (SPR) and SPR imaging (SPRi) for the analysis of biomarkers in real matrices.This talk will deal with recent developments in ultrasensitive and label-free molecular diagnostics from the point of view of analytical chemists.
Strategies for designing innovative ultrasensitive point of care diagnostics will be discussesd. Attention will be directed to the identification/selection of the suitable bioreceptors, to the molecular architecture building by coupling nanotecology to conventional assay design. In particular, the use of suitable nanostructures for improved system analytical performances willl be discussed.Finally, new emerging open fields of molecular diagnosis will be discussed.
Maria Minunni
and
Simona Scarano
Dipartimento di Chimica “Ugo Schiff”, Università
degli Studi di Firenze,Via della Lastruccia 350019 Sesto F.no (FI),
ItalyE-mail: maria.minunni@
unifi.it
BIOSENSING FOR MOLECULAR DIAGNOSTICS: CURRENT TRENDS AND PERSPECTIVES
Gunther Wittstock
Carl von Ossietzky
University of Oldenburg
Faculty of Mathe-matics and Natural
SciencesCenter of Interface
Science (CIS)Institute of Chemistry
D-26111 Oldenburg, Germany
E-mail: gunther.wittstock@
uni-oldenburg.de
The talk will explain how different scanning probe techniques can be used to elucidate structural and functional details of multi-enzyme microstructures.[1, 2] The structures are formed based on surface functionalized magnetic beads[3] or by layer-by-layer (lbl) deposition inside microfluidic networks.[4] This allowed to adjust precisely the activities of the immobilized enzymes such as glucose oxidase (GOx) and horseradish peroxidase (HRP), alkaline phosphatase, galactosidase or gluzcose dehydrogenase. The obtained lbl microstructures were characterized by scanning force microscopy for the topography of the deposited layers. The local enzyme activity was characterized by the substrate-generation/tip-collection mode[5] and the enzyme-mediated feedback[6] mode of the scanning electrochemical microscope (SECM).[7] These measurements provided quantitative information about the immobilized enzyme activity as a basis for adjusting enzyme loading for multi-enzyme structures that realize logical operations based on enzymatic conversions. The information on local HRP activity can also be obtained by optical readout using a fluorgenic substrate Amplex Ultra Red(TM) and reading with a confocal laser scanning microscope with a much higher repetition rate for image acquisition. Using those principles, a layout with HRP and GOx microstructures was realised that showed the functionality of an OR Boolean logic switch.[8]
[1] T. Wilhelm, G. Wittstock, Angew. Chem. Int. Ed. 2003, 42, 2247.[2] C. Zhao, G. Wittstock, Angew. Chem. Int. Ed. 2004, 43, 4170.[3] C. A. Wijayawardhana, G. Wittstock, H. B. Halsall, W. R. Heineman, Anal. Chem. 2000, 72, 333.[4] M. Burchardt, G. Wittstock, Bioelectrochemistry 2008, 72, 66.[5] C. Nunes Kirchner, M. Träuble, G. Wittstock, Anal. Chem. 2010, 82, 2626.[6] M. Burchardt, M. Träuble, G. Wittstock, Anal. Chem. 2009, 81, 4857.[7] G. Wittstock, M. Burchardt, S. E. Pust, Y. Shen, C. Zhao, Angew. Chem. Int. Ed. 2007, 46, 1584.[8] M. Burchardt, G. Wittstock, Langmuir 2013, 29, 15090.
COUPLING AND MONITORING CHEMICAL FLUXES OF MICROSTRUCTURED ENZYME LAYERS
Extracellular activity of electrogenic cells is commonly recorded using microelectrode arrays (MEAs) that consist of planar electrodes on a substrate in close contact with cells in culture. The main application of MEAs is the detection of action potentials in neurons. The neuronal response is typically recorded in the KHz regime. As a consequence, low frequency events are filtered out, as their detection is impaired oreven inhibited. Glia cells, as well as their transformed counterparts, glioma cells, do not exhibit action potentials. Instead, they exhibit distinctive, albeit ultra-weak, low frequency single-cell oscillations of the membrane potential. To measure this ultra-weak extracellular bio-electronic activity, we devised a sensitive detection method based on low impedance electrodes. The resulting transducer was located inside an incubator and all the instrumentation was shielded by a Faraday’s cage. The background noise level decreased from typically 40 μV in MEA recordings to less than 1 μV.
For the first time we could detect the minute, yet constantly occurring, low frequency membrane capacitive current oscillations across large populations of C6 glioma cells. By using specific pharmacological inhibitors, we could show that the glioma cell activity is primarily caused by the opening of voltage-gated Na+ and K+ ion channels.Malfunctioning glioma cells can develop to brain tumors. Glioma patients often suffer from epileptic seizures due to the tumors impact on brain electrophysiology. Here we show that seizure-like events in glioma cells spontaneously appear and correlate with extracellular pH reduction. We demonstrate that the transducer developed offers a unique approach for studying electrophysiological properties of large cell populations, as an in vitro reference for tumour bulks in vivo.
Paulo R.F. Rocha
Max Planck Institute for Polymer Research,
Ackermannweg 10, D-55128 Mainz, Ger-
manyE-mail: rocha@mpip-
mainz.mpg.de
ULTRA-SENSITIVE SYSTEM TO DETECT MINUTE IONIC GRADIENTS WITHIN GLIOMA CELLS
Wolfgang
Schuhmann a,
Felipe Conzuelo a,
Fangyuan Zhao a,
Adrian Ruff a,
Huaiguang Li b,
Volker Hartmann c,
Marc M. Nowaczyk c,
M. Rögner c,
N. Plumeré b
a Analytical Chemistry - Center for Electro-
chemical Sciences (CES),
b Center for Electro-chemical Sciences (CES) - Molecular
Nanostructures,
c Chair of Plant Biochemistry; Ruhr-Universität Bochum,
Universitätstr. 150, D-44780 Bochum,
Germany.E-mail: wolfgang.
Coupling of photosynthetic protein complexes to electrodes aiming on semiartificial photosynthetic solar energy conversion devices has gained considerable interest [1]. Upon illumination electrons are transferred between charge carriers and the PS1 protein complex, both at its reducing (FB) and oxidizing (P700) terminal sites [2]. Similarly, PS2 which is able to oxidize water at an integrated Mn-Ca-complex under formation of molecular oxygen has found increasing interest for photoelectrochemical applications despite its low stability [3].We have demonstrated that both PS1 and PS2 can be successfully wired to electrode surfaces using specifically designed redox polymers [4] and semiartificial photosynthetic devices can be conceived producing simultaneously electrical and chemical energy [5].In this contribution the following aspects to successfully wire PS1 and PS2 to electrode surfaces are discussed:1) Design of suitable redox polymers for wiring of PS1 and PS22) Optimizing photobioelectrochemical half cells for improving power output of PS1/PS2 related photobiofuel cells3) Modification of PS1 with Pt nanoparticles to achieve direct photon to hydrogen conversion4) The development of a scanning photoelectrochemical microscopy (SPECM) for the visua¬lization of local PS1 and PS2 activity by simulta-neous detection of the local photocurrent and locally generated O2 and H2.
[1] a) A. Badura, T. Kothe, W. Schuhmann, M. Rögner, Energy Environ. Sci. 4 (2011) 3263-3274. b) T. Kothe, S. Pöller, P. Fortgang, M. Rögner, W. Schuhmann, N. Plumeré, Chem. Eur. J., 20 (2014) 11029-11034. c) [2] A. Badura, D. Guschin, T. Kothe, M. J. Kopczak, W. Schuhmann, M. Rögner, Energy Environ. Sci. 4 (2011) 2435-2440.[3] A. Badura, D. Guschin, B. Esper, T. Kothe, S. Neugebauer, W. Schuhmann, M. Rögner, Electroanalysis 20 (2008) 1043-1047.[4] a) F. Zhao, K. Sliozberg, M. Rögner, N. Plumeré, W. Schuhmann, J. Electrochem. Soc. 161 (2014) H3035-H3041. b) F. Zhao, F. Conzuelo, V. Hartmann, H. Li, M. M. Nowaczyk, N. Plumeré, M. Rögner, W. Schuhmann, J. Phys. Chem. B 119 (2015) 13726-13731.[5] a) T. Kothe, N. Plumeré, A. Badura, M. M. Nowaczyck, D. A. Guschin, M. Rögner, W. Schuhmann, Angew. Chem. Int. Ed. 52 (2013) 14233-14236. b) V. Hartmann, T. Kothe, S. Pöller, E. El-Mohsnawy, M. M. Nowaczyk, N. Plumeré, W. Schuhmann, M. Rögner, PhysChemChemPhys 16 (2014) 11936-11941
SEMIARTIFICIAL PHOTOSYNTHESIS.HOW TO WIRE PHOTOSYSTEM 1 AND 2 TO ELECTRODES
For the emerging fields of biomedical diagnostics and environmental monitoring, where sensor platforms for in-situ sensing of ions and biological substances in appropriate aqueous media are required, electrolyte-gated organic field-effect transistors (EGOFETs) seem to be the transducers of choice. Due to the formation of an electric double layer at the electrolyte/organic semiconductor interface, they exhibit a very high capacitance allowing for low-voltage and water-stable operation. In combination with the outstanding properties of organic devices like biocompatibility, low-temperature processability on flexible substrates, as well as the possibility to tune the physical and chemical properties enhancing the selectivity and sensitivity, EGOFET-based sensors are a highly promising novel sensor technology. Here the realization of the ion-selective EGOFETs is discussed for reversible and selective ion detection. Moreover besides presenting the general selective sensing mechanism of ISMs, the optimization as well as the fabrication of a new pH sensitive ISM will be presented.
As a second approach a reference electrode free all organic K+ sensitive ion sensing platform on a simple paper sheet is presented. This sensing platform is based on two identical solid state ion selective electrodes (ISEs) solely consisting of a polymeric ion selective membrane (ISM) which is glued onto a PEDOT:PSS paper electrode. The ISEs are operated in series, taking full advantage of the so called “pulsetrode” concept. A 20-fold sensitivity enhancement compared to a classical potentiometric measurements was achieved without the need of a reference electrode. The high and stable response within a narrow concentration range is ideally suited for threshold sensors. These are, for example, of high relevance in food quality control and environmental monitoring.
This work was supported by the projects “BioOFET 2” and „MIEC-DEVs“ funded by the Amt der Steiermärkischen Landesregierung.
Emil J. W.
List-Kratochvil
Institut für Physik & Institut für Chemie
Humboldt-Universität zu Berlin
Brook-Taylor-Straße 612489 Berlin, Germany
E-mail: [email protected]
SELECTIVE AND REVERSIBLE ION-DETECTING SENSOR ELEMENTS IN AQUEOUS ENVIRONMENT BASED ON ORGANIC ELECTRONIC DEVICES
Ioannis Kymissis,
Chris Choi,
Youngwan Kim,
Steve Park,
Shyuan Yang,
Yu-Jen Hsu,
Elizabeth Olsen
Columbia University, New York, NY
E-mail: [email protected]
Biological systems can be examined using a range of properties including chemical signaling, electrical potential, ionic changes, mechanical movement, and changes in optical absorption. Organic semiconductors and the flexible systems that thin film devices enable have properties that are well positioned to interface with soft material and to detect and manipulate a number of these signals.
In this presentation, we will discuss the use of organic semiconductors as active switch and amplification elements allowing for array detection together with organic piezoelectric, optoelectronic, and chemically sensitive materials. We will present, in particular integrated systems for the measurement of medically relevant signals in hearing and brain function in humans. These systems are also functional in a number of secondary applications (such as robotic grip analysis and low power communication); these will be presented together with possible paths for near-term and long-term co-integration of these materials into electronic systems that provide actionable information using the measured quantities.
MECHANICAL AND OPTICAL SENSING OF BIOLOGICAL SYSTEMS USING THIN FILM ELECTRONICS
Although extensive studies to develop electronic devices that mimic the function of human nose and tongue have been conducted, most artificial sensors could not mimic the natural features of a human system and have limitations in terms of sensitivity and selectivity. Hence, a novel concept for sensor devices functionalized with odor and tastant-recognizing biomolecules was suggested. They are the bioelectronic nose and tongue. A bioelectronic nose generally consists of primary and secondary transducers. The primary transducer is a biological recognition element such as olfactory receptors. The secondary transducer is a highly sensitive nanodevices that convert biological events into measurable signals. In this presentation, the basic concept and principles of bioelectronic nose and tongue will be presented. In addition, specific characteristics of bioelectronic nose and tongue and the current issues will be discussed.
Tai Hyun Park
Advanced Institutes of Convergence
TechnologySchool of Chemical and
Biological Enginee-ring, Seoul National
UniversitySeoul, Korea
E-mail: [email protected]
BIOELECTRONIC NOSE AND TONGUE:INTEGRATION OF HUMAN RECEPTORS AND NANO DEVICES
Magnus Berggren a,
Eleni Stavrinidou a,
Roger
Gabrielsson a,
Eliot Gomez a,
Xavier Crispin a,
Ove Nilsson b,
Daniel T. Simon a
a Laboratory of Organic Electronics, Department of Sci-
ence and Technology, Linköping University,
SE-601 74 Norr-köping, Sweden
b Department of Forest Genetics and
Plant Physiology, Swedish University of
Agricultural Sciences, SE-901 87 Umeå,
SwedenE-mail: [email protected]
The roots, stems, leaves, and vascular circuitry of higher plants are responsible for conveying the chemical signals that regulate growth and functions. From a certain perspective, these features are analo-gous to the contacts, interconnections, devices, and wires of discrete and integrated electronic circuits. Although many attempts have been made to augment plant function with electroactive materials, plants’ “circuitry” has never been directly merged with electronics. Here, we report analog and digital organic electronic circuits and devices manufactured in living plants. The four key components of a circuit have been achieved using the xylem, leaves, veins, and signals of the plant as the template and integral part of the circuit elements and functions.
First, in the work here reported we have primarily used Rosa floribunda as the plant model system. Formulations and derivatives of PEDOT were used to define the four key-components of circuits inside Rosa floribunda cuttings. In one approach PEDOT:PSS was composited with nano-fibrillated cellulose to enable the formation of free-standing electrode systems from water emulsions. Such electrode systems were vacuum infiltrated into the spongy parenchyma to define areal, ana-
ELECTRONIC PLANTS
logue display electrode systems along the bottom part of the leaves. In a second approach, a polyelectrolyte PEDOT derivative was used to enable self-organization of long-ranged electronic wire and device systems along the xylem vascular system inside the stem. These wire systems were then used to define transistors and simple logic circuits for signal amplification and processing.
Secondly, the organic electronic ion pump is a device that can translate an electronic addressing signal into the delivery of a biochemical signal, such as a neurotransmitter and plant hormones. This device was then applied to the roots and root hairs of Arabidopsis thaliana. By delivering the plant hormone auxin, we successfully managed to control the growth pattern of root protrusions.
With integrated and distributed electronics in plants, one can envisage a range of applications including precision recording and regulation of physiology, energy harvesting from photosynthesis, and alternatives to genetic modification for plant optimization.
1. E. Stavrinidou, R. Gabrielsson1, E. Gomez1, X Crispin, O. Nilsson, D. T. Simon and M. Berggren, Science Advances 20 Nov 2015, vol. 1, no. 10, e1501136, DOI: 10.1126/sciadv.1501136
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