The study of cysteine molecule coated magnetic Fe3O4 nanoparticles via sonochemical method for bio-applications

Kevin J. Schilling, Joo Seob Lee, and Patrick A. Johnson

Biointerfacial Engineering Laboratory

Department of Chemical & Petroleum Engineering

Introduction Methods

ACKNOWLEDGMENTS

Advisor : Dr. Patrick A. JohnsonMentor: Joo Seob LeeWe acknowledge the financial support from the McNair Scholars Program at the University of Wyoming

Problem

Data Analysis

Hypothesis

Bio-Application

(1) Magnetic nanoparticles, functionalized with cysteine improve the solubility and performance characteristics for biomaterials in aqueous & non-aqueous conditions.

(2) Different conditions such as sonication time, temperature, and the concentration of DL-Cysteine will affect the magnetic Cys-Fe3O4 colloidal suspensions due to the surface structure of Cys-Fe3O4.

Transmission Electron Microscopy (TEM)

Scanning Electron Microscopy (SEM)

• Determine structure• Magnetic core with shell

• View individual particle and clusters

Enzyme Immobilization

DNA Binding Ability

Biosensors

• Two primary binding groups• Carboxyl (-COOH)• Amine (-NH2)

• Covalent binding

This study will examine cysteine coated magnetic nanoparticles (Cys-Fe3O4) fabricated with sonochemical approaches, using (1) metal salt mixtures (e.g., Fe3+, Fe2+) and (2) iron pentacarbonyl (Fe(CO)5) in conjunction with a small molecule surfactant. A comparison of the two methods in order to create more uniform dispersion will be performed in order to prevent cysteine-cysteine interactions on the surface of Cys-Fe3O4.

+

) ) )Time, t

• Sonicate iron pentacarbonyl for 3 hours• Wash with solvent (e.g. double-distilled water,

acetone, or methanol)

DL-Cysteine Iron Magnetic Nanoparticle

• Double helix structure in DNA

• Phosphate groups on 3’ and 5’ ends of sugar backbone

• Amine binding• Nitrogen attack

phosphate• Carboxyl binding

• Carboxyl group (C=O) attack phosphate

• Possible addition of acid

• Chemically bind Cys-Fe3O4 to glass substrate

• Immobilize the enzyme on the Cys-Fe3O4 coated surface

• Get diagnostic reading from enzyme reaction

TEM

Fourier-Transform Infrared Spectroscopy (FT-IR) & Raman Spectroscopy

• Characterization of coated/uncoated particles

• Tilted image of dried particles (3D)• Determine size (nm) and morphology

Fe3O4

Cys-Fe3O4

• Add iron pentacarbonyl Fe(CO)5

• Inject DL-Cysteine into solution• Sonicate for 3 hours• Wash with solvent• Let (magnetically) precipitate

Fe3O4

) ) )Time, t

Iron PentacarbonylIron Magnetic Nanoparticle

Dynamic Light Scattering & Zeta Potential (+/-, mV)

• Determination of size and colloid stability• Measure surface charges and the particle

mobility

SEM

FT-IR

In past years, magnetic Fe3O4 nanoparticles have been a tremendous asset to the biomaterial field and as such there has been a high desire to synthesize and optimize these nanoparticles. These magnetic Fe3O4 particles are very diverse. They can be used as catalysts, be used in drug delivery, or aid in magnetic hyperthermia treatment. These nanostructured particles being created have super paramagnetic behaviors; these magnets can flip their magnetic direction due to either temperature or the presence of a magnetic field. In contrast, magnetic Fe3O4 particles can switch their magnetic field to attract the other particles and aggregate and precipitate out of solution.

Structure of DNA

DI-Water

DI-Water

Cys-Fe3O4 Complex