Chemo-Electrical Gas Sensors Based on Conducting Polymer Hybrids

Conducting polymer (CP) hybrids, which combine CPs with heterogeneous species, have shown strong potential as electrical transducers in chemosensors. The charge transport properties of CPs are based on chemical redox reactions and provide various chemo-electrical signal transduction mechanisms. Combining CPs with other functional materials has provided opportunities to tailor their major morphological and physicochemical properties, often resulting in enhanced sensing performance. The hybrids can provide an enlarged effective surface area for enhanced interaction and chemical specificity to target analytes via a new signal transduction mechanism. Here, we review a selection of important CPs, including polyaniline, polypyrrole, polythiophene and their derivatives, to fabricate versatile organic and inorganic hybrid materials and their chemo-electrical sensing performance. We focus on what benefits can be achieved through material hybridization in the sensing application. Moreover, state-of-the-art trends in technologies of CP hybrid sensors are discussed, as are limitations and challenges.