Enrichment-catalytic synergistically enhanced electrochemiluminescence sensors based on IRMOF-3/CdTe for ultrasensitive detection of organophosphorus pesticides.

To prevent organophosphorus pesticide (OPs) residues from threatening ecological environment safety and human health, the development of rapid and accurate monitoring methods is crucial. Herein, a newly quantum dot-functionalized metal-organic framework composite (IRMOF-3/CdTe) was synthesized, which achieved super strong cathodic electrochemiluminescence (ECL) emission in aqueous media. Among them, as a co-reaction accelerator, IRMOF-3 could efficiently enrich K2S2O8 and catalyze its generation of sulfate radical (SO4•-), while protecting metastable intermediates from environmental quenching, synergistically improving the ECL signal intensity. Moreover, by optimizing the synthesis ratio of IRMOF-3/CdTe and combining ECL intensity and electrochemical impedance spectroscopy (EIS) analysis, it was revealed for the first time that IRMOF-3 exerts a dual-edged effect on the ECL performance of CdTe. Based on the efficient ECL performance of IRMOF-3/CdTe and the inhibitory effect of OPs on acetylcholinesterase (AChE) activity, a highly sensitive ECL enzyme biosensor was constructed to detect profenofos (Pff). The fabricated biosensor exhibited a wide detection range (134 fM-1.34 mM) and a low detection limit (44.7 fM), and was successfully applied to the detection of Pff residues in actual samples (vegetables, milk and Yangtze River water). This study provided a new idea for the design of efficient ECL enzyme biosensors, which was of great significance for ensuring ecological and food safety.