Chemicapacitive microsensors for chemical warfare agent and toxic industrial chemical detection

Chemical Sensors for Environmental Monitoring and Homeland Security

“…In this approach, the enzyme hydrolyzes organophosphate to an electroactive species, which was then determined amperometrically. 30 has reported another type of transduction mechanism, a chemicapacitive microsensor consisting of 10 parallel plate (Fig. 3) 30 ) to mimic the canine system (which is known to be the most reliable and mobile method of detection).…”

“…30 has reported another type of transduction mechanism, a chemicapacitive microsensor consisting of 10 parallel plate (Fig. 3) 30 ) to mimic the canine system (which is known to be the most reliable and mobile method of detection). In many chemical sensor systems, a receptor layer is used to bind the target explosives of interest and trigger a change in physical or chemical parameter.…”

An assessment of sensing technologies for the detection of clandestine methamphetamine drug laboratories

“…In such devices, the change in capacitance results from either the relative displacement of the two electrodes [17], or a change in the dielectric properties of a chemically selective and absorbent dielectric material [18], commonly a polymer. The transduction mechanism is intrinsically non-specific and the sensors require appropriate chemically selective material.…”

“…However, a significant disadvantage of surface stress chemicapacitors is their response time (about 35 min) [17]. Parallel-plate chemicapacitors respond significantly faster (<1 s) [18]. Recently, there has been a focus on the application of nanomaterials for improved sensitivity [21].…”

“…Although chemicapacitive sensors are beginning to be commercialized, published results report on sensors that are less sensitive than some of the more mature technologies. The limited available examples for chemicapacitors in the literature demonstrate sensing only for ammonia [18] and toluene [20], although there is no intrinsic reason why such sensors could not detect a majority if not all of the target analytes. If coupled to a preconcentration stage, current parallel-plate chemicapacitors could be applied to the stationary detection of target analytes, due to their moderately low detection limits and quick response times.…”