Nanosensors for trace explosive detection
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Transcript of Nanosensors for trace explosive detection
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