Abstract
Currently available TNT sensors are characterized by high sensitivity, but low specificity, which limits the detection of TNT in dirty environments. We report here a TNT sensor designed to measure the displacement of a TNT-specific antibody by quartz crystal microbalance (QCM). This sensor combines high sensitivity of detection (0.1 ng/mL) with the ability to distinguish TNT from molecules with similar chemical properties. Particularly, the reliability of this method for the detection of TNT in dirty environments was investigated by using fertilizer solution and artificial seawater. Instead of measuring actual binding of TNT, the method described is based on the displacement of an anti-TNT antibody, which allows quantifying the concentration of TNT in solution with higher sensitivity. In addition, by utilizing the rate of antibody displacement, the detection time is significantly decreased from hours, which would be necessary to measure the frequency change at equilibrium, to minutes. A Langmuir kinetic model was used to describe the molecular interactions on the surface of the sensor and to establish a standard curve to estimate on-site TNT detection. In summary, QCM detection of anti-TNT antibody displacement provides a method for rapid detection of TNT with high sensitivity and specificity.
Highlights
The rapid and reliable detection of explosives has gained increasing attention, due to health and public safety reasons [1]
We have developed a rapid and accurate quartz crystal microbalance (QCM) based displacement assay for the detection of TNT in liquid phase, by exploiting the cross reactivity of an anti-TNT antibody (A1.1.1) for TNT analogs
The robustness of this QCM based TNT sensor was confirmed by evaluating TNT detection in dirty environments, such as fertilizer and seawater, and the limit of detection achieved was comparable to that measured in pure TNT solution
Summary
The rapid and reliable detection of explosives has gained increasing attention, due to health and public safety reasons [1]. A variety of technologies have been developed for the detection of TNT They can be broadly classified as physical, chemical and biological methods, based on the detection mechanism and output signal. The limit of detection for TNT was reduced to ~0.023ng/mL using a hybrid material composed of gold nanorod and quantum dots This method, exhibits relatively low specificity, which prevents distinguishing TNT from other nitroaromatic compounds with similar chemical properties [17]. Biological methods typically present enhanced specificity due to the use of TNT specific molecules, such as antibodies [18,19], and molecularly imprinted polymers (MIPs) [20,21] Most of these reported sensors lack data comparing their performance in a dirty environment. The purpose of this study is to develop a rapid and accurate sensor that combines the high sensitivity of chemical methods with the high specificity of biological methods for the detection of TNT in aqueous solutions containing similar molecules
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
