Promoting effect of ReS2 microsphere on iridium complex nanosheets ECL and its sensing application for bisphenol A

The inherent water insolubility of iridium complexes seriously restricts their application in aqueous electrochemiluminescence (ECL) sensing systems. In order to solve this problem, this study innovatively used water-soluble polymer polyvinyl alcohol to encapsulate the iridium complex ([Ir(dFppy) 2 (d(t-Bu)bpy)](PF 6 )) in a hydrogel, and successfully obtained nanosheets of iridium complex (IrNS) with good dispersion. Systematic studies on the behavior of IrNS ECL in aqueous media showed strong and stable cathodic ECL when persulfate (S 2 O 8 2− ) was used as a co-reactant. Notably, the introduction of rhenium disulfide microspheres (ReS 2 MS) can produce significant cathodic ECL enhancement effects by efficiently catalyzing the conversion of S 2 O 8 2− to generate more SO 4 − . Bisphenol A (BPA) can react with S 2 O 8 2− to reduce the ECL intensity, based on which an ECL sensor was constructed for its detection. Under optimal conditions, ECL intensity varied linearly with BPA concentration, ranging from 1.0 × 10 −10 to 1.0 × 10 −5 mol L −1 with a detection limit of 5.5 × 10 −12 mol L −1 . The fabricated sensors with high sensitivity and selectivity provide a new avenue for the application of water-insoluble iridium complexes in ECL sensing.