Advances in Modifying Carbon-Supported Single-Atom Nanozymes for Boosting Biosensing

Carbon-based single-atom nanozymes (CB-SANzymes) have garnered significant attention in recent years due to their unique ability to mimic the active sites of natural enzymes. They exhibit not only maximized atom utilization efficiency but also strong metal-substrate interactions that effectively modulate the electronic structure of metal centers. Furthermore, carbon substrates facilitate rapid electron transfer during biosensing processes and enhance the stability of single-atom sites. These advantages make CB-SANzymes highly promising for biosensing applications. This review examines the fundamental properties of CB-SANzymes and discusses strategies for their modifications. Key strategies include increasing single-atom density, tuning the coordination environment, leveraging multimetal synergy, and engineering carbon substrates via heteroatom doping and defect construction. We also summarize the recent advances of CB-SANzymes in diverse biosensing platforms, such as colorimetric, fluorescent, and electrochemical systems. Their contribution to enhancing the sensitivity, selectivity, and accuracy of these systems is emphasized. Finally, current challenges and future prospects in the development and application of CB-SANzymes are discussed, with the aim of providing insightful guidance for further advancements in this rapidly evolving field.