Regioregular polythiophene field-effect transistors employed as chemical sensors

Soluble alkyl- and alkoxyl-substituted regiochemically defined polyterthiophenes are used as active layers in sensing organic thin films transistors (OTFTs). Such active layers have a polycrystalline morphology and the substituent chains bear different associated dipole moments. Volatile organic compounds carrying moieties that are chemically homologous to the selected polymers’ side chains are used as analytes. Both electrical and quartz crystal microbalance sensor responses are evaluated and a rationale for the sensing mechanisms involving weak polar/polar-type interactions is proposed.