(165a) Electrochemical Sensor for Toxic Chemicals Based on Nanodeposit and Enzyme

There are strong demands for sensors of toxic chemicals such as organophosphate (OP) and cyanide. One of the approaches for high-selectivity sensor is to utilize a specific chemical or biological interaction of the target molecule. Recently, we showed that the electrochemical sensor based on oxime chemistry has high selectivity, in which keto-oxime reacts with OP toxins and produces cyanide which is detected electrochemically. One of the bottlenecks in detecting an ultra-low level of toxic chemicals is the detection limit of the sensing electrode. We take two approaches to build a highly sensitive and selective sensing electrode. (1) Several silver-based materials are evaluated and optimized, such as silver nanodeposits on graphite or nanoporous silver membrane, which would show better performance than bulk electrode. (2) Enzyme-based sensing scheme is utilized, which would show inherently high chemical selectivity toward the target molecules.