Nanosensors for trace nitroaromatic explosive detection

by Melike Şeyma Kadayıfçı

Outlines

Introduction

Types of Nanosensors

Nanomaterial-based sensors for nitroaromatic explosive detection

Application:A Hybrid Nanosensor for TNT Vapor Detection

Challanges in moving toward practical applications

Conclusions

Introduction

What is a Nanobiosensors ?

A biosensor is a measurement system for the detection of an analyte that combines biological compenent with a physicochemical detector, and a nanobiosensor is a biosensor that on the nano-scale size (1).

Figure 1: Image of a biosensor

Biosensor system

Figure 2: Components of biosensor system

Types of Nanosensors

NanoSensors

Optical Nanosensors

Ambient Light

Nanosensors

Proximity Nanosensor

s

Biological Nanosensor

Antibody/Antigen

Interaction

DNA Interaction

Enzymatic Interaction

Chemical Nanosensor

s

Chemical Compositio

n

Molecular Concentrati

on

Physical Nanosensor

s

Pressure

Force

Mass

Displacement

Nanomaterial-based sensors for nitroaromatic explosive detection:

Carbon-based nanomaterials

Metal-based nanomaterials

Nanoporous materials

Quantom dot-based nanomaterials

Hybrid nanomaterials : Pt nanoparticles ensembled on graphene hybrid nanosheet (2)

Application: A Hybrid Nanosensor for TNT Vapor Detection

A hybrid nanosensor based on the electrochemical reduction of TNT and the interactionof the reduction products with conducting polymer nanojunctions in an ionic liquid.The sensor simultaneously measures the electrochemical current from the reduction of TNT and the conductance change of the polymer nanojunction caused from the reduction product.(3)

Figure 4

A Hybrid Nanosensor for TNT Vapor Detection

Researchers have also compared the effects of the same interferents on the electrochemical detection (Figure 3b). They found that the electrochemical detection alone is more prone to interferents, which underscores the importance of the integrated nanojunction and electrochemical sensor on the same chip (4).

Figure 5

Challanges in moving toward practical applications

Creating a sensor that is both sensitive and selective is only the first part of the challenge.

The second part involves bringing explosives from the environment to the sensor element.(5)

Discrimate the analytes from various interferents in variable enviroments.

Sample collection; because nitroaromatics have extremly low vapor pressures(e. g TNT)

Since explosive molecules stick to surfaces, delivery lines and other components need to be maintained at a higher temperature. Operating at higher temperatures decreases sensitivity.

Conclusion

Nano scale materials often possess unique optical and electricalcharacteristics, which could enhance the sensitivity and selectivity with incorporation of some existing techniques.

As new nanomaterials with specific characteristics are developing, analytical chemists try to apply them for analytical purposes. Efforts in developing new sensors derive from one goal and that is producing fast, sensitive, selective, and low cast sensors.

In the application part, Researchers have demonstrated an integrated electrochemical and electrical nanosensor for sensitive and selective detection of nitroaromatic explosives vapors. The sensor utilizes both the electrochemical signatures of the reduction of the analytes and specific interactions of the reduction products with the polymer nanojunction to achieve excellent selectivity.

References

1) http://www.deu.edu.tr/ders-katalog/2014-2015/eng/en_132_9665_4800.html2) Farhad Akhgari, Hassan Fattahi, Yones Mosaei Oskoei, Recent advances in

nanomaterial-based sensors for detection of trace nitroaromatic explosives, Sensors and Actuators B 221 (2015) 867–878

3-4) Alvaro Dı´az Aguilar,Erica S. Forzani,Mathew Leright,Francis Tsow,Avi Cagan,Rodrigo A. Iglesias,Larry A. Nagahara,Islamshah Amlani,Raymond Tsui,And N. J.

Tao, A Hybrid Nanosensor for TNT Vapor Detection, DOI: 10.1021/nl902382s |Nano Lett.2010,10, 380-384

5) Larry Senesac and Thomas G. Thundat, Nanosensors for trace explosive detection, march 2008 |volume11 | number 3