Facile synthesis of an indacenodithiophene-based conjugated polymer for acid vapor sensing

The use of organic conjugated polymers in sensors has attracted greater attention due to their application in materials technology. In the present communication, we utilized Schiff's condensation polymerization reaction for the synthesis of a novel conjugated polymer poly(tetrahexadecyl-dihydroindacenodithiophene)-alt-(p-phenylenediimine) (PIDTPD) consisting of indacenodithiophene (IDT) and p-phenylene diamine (PDA) units for use in acid vapor sensing. Conventionally, the characteristics and applications of conjugated polymers are affected by their constituents. The imine bond between the components of organic materials has received little attention compared to their active counterparts. In order to explore the practical application of conjugated polymers in sensors, we employed PIDTPD in a paper sensor and illustrated the impact of mono- and bis-protonation on the pristine material in driving a noteworthy protonation-induced color shift toward the longer wavelength region via acidochromism.