Thiol-yne click reaction mediated photoelectrochemical detection of multi-sulfhydryl compounds based on diacetylene functionalized conjugated polymer

Most existing solutions for thiol detection require the addition of extra chemical agents to produce detection signals. However, the tedious operations in the sensing process are unfavorable for the real-time dynamic detection of thiol molecules. Herein, we present an all-organic graphene/poly(1,3,5-triethynylbenzene) (PTEB) composite for rapid and direct photoelectrochemical (PEC) analysis of multi-sulfhydryl compounds through specific thiol-yne click reaction. The non-covalent interfacial π-π interaction between the graphene and PTEB improves the optoelectronic properties of PTEB, which sensitizes the photocathode toward thiol detection with high sensitivity, broad linear range, and low detection limit. The theoretical calculation reveals that abundant 1,3-diyne linkages of PTEB are -SH sensitive active sites in PEC detection. Furthermore, a homemade sensing instrument has achieved real-time monitoring of thiol, suggesting its feasibility as an online sensor or a reaction monitor embedded in the industrial production line. Such progress holds promise for developing a diacetylene functionalized conjugated polymers-based -SH responsive platform for practical application in chemical production and quality control.