According to an embodiment, a microelectromechanical systems (MEMS) transducer includes a substrate with a first cavity that passes through the substrate from a backside of the substrate. The MEMS transducer also includes a perforated first electrode plate overlying the first cavity on a topside of the substrate, a second electrode plate overlying the first cavity on the topside of the substrate and spaced apart from the perforated first electrode plate by a spacing region, and a gas sensitive material in the spacing region between the perforated first electrode plate and the second electrode plate. The gas sensitive material has an electrical property that is dependent on a concentration of a target gas.