Achieving humidity-insensitive ammonia sensor based on Poly(3,4-ethylene dioxythiophene): Poly(styrenesulfonate)

Abstract Sensor devices using different poly(3,4-ethylene dioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) based active layers were fabricated with all solution processes. It was found the devices of pristine PEDOT:PSS presented high response to humidity change, but little response to ammonia (NH 3 ). In contrast, the DMSO doped PEDOT:PSS devices were nearly insensitive to humidity change, and exhibited significantly improved responsivity to NH 3 . Incorporation of AgNWs into the DMSO doped PEDOT:PSS film further enhanced the responsivity to NH 3 , while maintaining insensitivity to humidity changes. The mechanisms for such different sensing properties were revealed. Finally, the fabricated NH 3 and humidity sensors using different PEDOT:PSS based films were integrated with a near field communication (NFC) chip to realize a flexible system, which was able to be attached on the packaging film for monitoring the meat freshness, with the sensing data being read out wirelessly by a smart phone.