Dual enzyme electrochemiluminescence sensor based on in situ synthesis of ZIF-67@AgNPs for the detection of IMP in fresh meat

Abstract

Inosine 5′-monophosphate as an umami substance contributes to the palatability of meat, and it is considered to be an essential indicator for the freshness and quality of meat. Herein, we reported a dual enzyme electrochemiluminescent biosensor based on ZIF-67@AgNPs-Luminol nanocomposites for the detection of inosine 5′-monophosphate in fresh meat. Silver nanoparticles (AgNPs) are regarded as excellent catalysts for biosensing, however, the tendency to aggregate limits their wide applications. In this paper, AgNPs were formed on the dodecahedral surface of ZIF-67 by reduction of luminol, which effectively prevented the aggregation of AgNPs. At the same time, the double H2O2 generated by inosine 5′-monophosphate that was catalyzed by 5′-nucleotidase and xanthine oxidase respectively greatly improved the signal of the electrochemiluminescent reaction. The results showed that the prepared ZIF-67@AgNPs-Luminol biosensor had a linear range of 0.003–25 g/L with a satisfactory detection limit of 0.0017 g/L. Furthermore, the developed electrochemiluminescent sensor was successfully applied to detect actual meat samples with outstanding performance.