ZnIn2S4/g-C3N4 heterojunction enabled PEC-ECL sensing interface for quenching assay of fipronil

Abstract

A ZnIn2S4/g-C3N4 heterojunction enabled dual-mode photoelectrochemical-electrochemiluminescent (PEC-ECL) biosensor was constructed for quenching detection of fipronil, in which the inputs of target fipronil triggered the double-step catalytic hairpin assembly (CHA) circuits, leading to the introduction of quencher MnO2 nanoflowers (NFs). Leveraging the excellent changes of signals, this biosensor exhibited a wide linear range with a detection limit of 6.8 fM in PEC mode and 6.2 fM in ECL mode. Furthermore, it allowed for fipronil analysis in lettuce and egg samples, possessing excellent consistency with those of standard method, which confirmed its potential for food safety monitoring.