Trace level detection of nerve agent simulant by using cantilever-based aptasensor

This paper reports a piezoresistive (PZR) cantilever aptasensor for a sensitive and specific detection of dimethyl methylphosphonate (DMMP), a representative simulant of sarin and organophosphorus pesticides (OPPs), in neutral solution for the first time. By improving the design and fabrication processes, the output fluctuation of the PZR cantilever has been decreased to 1 μV at a 3 V bias voltage. Aptasensor functionalized by a 78-mer 5´-biotinylated aptamer not only realized the trace detection of DMMP with a limit of detection (LOD) of ppb level, but also showed excellent specific response. Finally, a kinetic model based on pseudo-first-order kinetics was developed to analyze the aptamer/DMMP interactions of the PZR cantilever sensors.