LAUSR

A chemical sensor for cysteine (Cys) was fabricated based on a fluorescent oligo(p-phenylene ethynylene)s (OPEs) and OPE-graphene oxide (GO) composite. OPE with cyanoacrylate terminal groups were synthesized by a Pd-catalyzed Sonogashira coupling reaction and Knoevenagel condensation for use as a chemical sensor for Cys. The optical properties and Cys sensing capability of the cyanoacrylate modified OPE and OPE–GO composite were investigated. In addition of Cys, the fluorescence of OPE was blue-shifted and decreased (fluorescence turn-off), while the fluorescence of the OPE–GO composite was enhanced (fluorescence turn-on). Thus, OPE with cyanoacrylate terminal groups and OPE–GO composite acts a highly sensitive fluorescent chemical sensor for Cys.