“…In our previous studies, we observed that active sites in a single particle induce the generation of hydroperoxide intermediates, which behave as coreactants to remarkably enhance ECL emission from luminol. 27,28 As a result, the ECL intensity of the particles is visualized, which has been proven to be correlated with their catalytic activity. Nevertheless, time resolution must be sacrificed to obtain sufficient ECL emission from single particles due to the relatively weak ECL emission.…”