Dual WO3 based sensors to selectively detect DMMP in the presence of alcohols

A size selective approach to improving selectivity in semiconducting metal oxides (SMO) sensors was obtained by tailoring the architecture of WO3 powders. The key for achieving high selectivity is based on using a dual sensor configuration where the response on a porous WO3 powder sensor was compared to the response on a nonporous WO3 powder sensor. Detection selectivity between methanol and dimethyl methylphosphonate (DMMP) is obtained because the access of a gas molecule in the interior pore structure of WO3 is size dependent leading to a size dependant magnitude change in the conductivity of SMO sensor.