DESIGN OF CHEMORESISTIVE SENSORY MATERIALS - POLYTHIOPHENE-BASED PSEUDOPOLYROTAXANES

Herein we report conducting polymer-based sensors which transduce reversible, noncovalent, and nonredox-dependent molecular recognition events into measurable changes in conductivity. These chemoresistive polymers are derived from bithiophenes containing cyclophane receptors capable of forming self-assembled pseudorotaxane complexes with paraquat. The electrostatic perturbations arising from pseudopolyrotaxane formation cause a decrease in carrier mobility and thus lower the conductivity. The chemoresistive response was found to be consistent with decreased carrier mobility and exhibited an enhanced sensitivity to analyte-promoted electrostatic perturbations relative to the voltammetric response. Polymer-based devices which demonstrate a real time chemoresistive response to paraquat are also reported.