Sulfur doped hollow cobalt–nitrogen–carbon oxidase-mimicking nanozyme enable sensitive chemiluminescence sensing serum total antioxidant capacity

Heteroatom doping is one of most important methodology for heightening catalytic activity of a nanozyme through modulating electronic configuration and coordinated environment of metal atoms. Here, a nitrogen/sulfur co-doped cobalt-decorated hollow carbon structure (Co S/N C) was fabricated through a simple and manageable template-assisted synthetic strategy, following high-temperature carbonization treatment. Remarkably, the Co S/N C has superior oxidase-mimicking activity than its counterparts and displays excellent catalytic action on the chemiluminescence (CL) reaction between luminol and dissolved oxygen (O 2 ). The Co S/N C nanozyme-based CL system is highly sensitive to physiologically relevant antioxidants of both species including single electron transfer and hydrogen atom transfer. The detection limits can be reached as low as 3 nmol·L −1 ascorbic acid, 30 nmol·L −1 uric acid, 16 nmol·L −1 glutathione, and 28 nmol·L −1 cysteine. The total antioxidant capacity (TAC) of human serums has been determined in order to assess the feasibility of the CL system. The results of serum TAC, with ascorbic acid as an equivalent model, show a good consistency with those obtained by the standard CUPRAC method. This work not only benefits the rational design of a high catalytic functionality nanozyme, but also constructs a robust TAC detection platform for monitoring oxidative stress-related diseases.