Carbon-based atomically dispersed catalysts for enzyme catalysis applications

Natural enzymes display exceptional catalytic efficiency and substrate specificity, yet their broad implementation is often hindered by insufficient operational stability, high production costs, and poor recyclability. Carbon-based nanozymes provide enhanced robustness and favorable biocompatibility; however, conventional designs frequently suffer from a low density of genuinely active sites and ill-defined structure–activity relationships. Atomically dispersed catalysts—including single-atom sites, dual-atom ensembles, and sub-nanometric clusters—offer precisely identifiable active centers and near-complete metal-atom utilization, thereby enabling both performance optimization and mechanistic interrogation. In this review, we comprehensively summarize recent progress in carbon-supported atomically dispersed nanozymes, with a particular focus on controllable synthesis and atomic-level regulation strategies, such as defect engineering, heteroatom doping, confinement effects, coordination-environment tailoring, axial modulation, and inter-site cooperativity. We further discuss how this design principles govern reactive oxygen species generation/scavenging and cascade enzyme-mimicking pathways, and highlight representative applications in biomedicine (e.g., tumor therapy and antibacterial interventions), biosensing, and environmental remediation. Finally, we outline key remaining challenges—including scalable and reproducible manufacturing, long-term stability of atomic sites in complex media, and systematic in vivo biosafety assessment—and provide an outlook toward multifunctional integration and stimuli-responsive nanozyme platforms for practical translation.