Toward Membrane-Free Amperometric Gas Sensors: A Microelectrode Array Approach

Room temperature ionic liquids (RTILs) have been applied to a microelectrode array and been demonstrated to form effective, membrane-free amperometric gas sensors. Determining the RTIL [P6,6,6,14][FAP] as the most appropriate choice for extended use, the amperometric quantification of oxygen has been demonstrated. The response of the sensor was quantified by both cyclic voltammetry and chronoamperometry. A range of O2 contents (2−13% v/v) and RTIL layer thicknesses (from ca. 6 to 125 μm) have been investigated. The combination of microelectrode array and RTIL, as well as the absence of membrane and volatile solvent, results in an elegant, easy to calibrate gas sensor with potential utility in standard and nonstandard conditions.