Zn/Co bimetallic zeolite imidazole framework electrocatalysts and its application in constructing cathodic luminol electrochemiluminescence system

Herein, ZnCo bimetallic zeolite imidazole framework (ZnCo-ZIF) nanocubes were synthesized and used as 2e − oxygen reduction reaction (2e-ORR) electrocatalysts. ZnCo-ZIFs showed excellent ORR catalytic activity, which was benefit for producing reactive oxygen species (ROS) efficiently and enhancing the electrochemiluminescence (ECL) emission from luminol/H 2 O 2 system. The reaction mechanism investigation implied that ORR reaction could produce ROS, and the ECL response exhibited a positive correlation with the catalytic activity of ZnCo-ZIFs promoter. In addition, the electrocatalytic activity of different Zn/Co molar ratio (1/ 9, 1/5, 1 /1, 5/1 and 9/1) were investigated, the results showed that ZnCo-ZIF-IV with Zn/Co molar ratio of 5/1 displayed the highest ORR electrocatalytic performance, and the onset potential, H 2 O 2 production rate, the faraday efficiency were 0.67 V (vs. RHE), 67.17 % and 50.74 %, respectively. Finally, an ECL immunosensor based on the promoting effect of ZnCo-ZIF-IV nanocubes on the luminol/H 2 O 2 ECL system was proposed for the sensitive zearalenone assay. This strategy offers a new way to study the luminol-cathodic ECL system.