Revolutionary Explosive Sensor Under Development
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The development of sensors for explosives such as TNT is of huge interest. TNT is an explosive material widely used for military, industrial, and mining applications. Its reduction products are known to be toxic and carcinogenic to humans and may contaminate and accumulate in soils and drinking water. The procurement of TNT by terrorists to build improvised explosive devices (IEDs) poses a real and ongoing threat.
Electrochemistry is emerging as a viable technique for explosives detection “in the field” due to its many advantages, including low-cost instrumentation, portability, durability, sensitivity, selectivity, and fast response times. One common electrochemical technique employed in chemical sensors is amperometry, according to sciencetrends.com. It is based upon applying a voltage on the sensor electrode and measuring the current generated – this current is directly related to the concentration of the target analyte.
A research team led by Dr. Debbie Silvester from Curtin University in Perth, Western Australia, have devised a new electrochemical technique to detect and quantify trace amounts of the harmful TNT contaminant in water samples. They have mixed RTILs with common and commercially available methacrylate polymers to produce highly viscous “gel polymer electrolytes” (GPEs) which do not readily flow. The GPE can be easily casted as a film on top of the miniaturized planar electrode device.
The sensor device was able to quickly and easily quantify TNT concentrations at typical groundwater contamination levels of TNT, with a low limit of detection of 0.37 µg/mL. The low-cost and portability of the sensor device, along with the minimal amounts of GPE materials required, make this a very promising technology for the onsite monitoring of explosives. Furthermore, this hydrophobic polymer/RTIL based sensors can be potentially be extended to enable the detection and sensing of other analyte species including gases and other explosive compounds.
