Carbon-Based Nanozymes: Catalytic Mechanisms, Performance Tuning, and Environmental-Biomedical Applications

Abstract

Carbon-based nanozymes, a significant subclass of nanomaterials mimicking natural enzyme catalytic functions, offer superior thermal and chemical stability and enhanced biocompatibility compared to natural enzymes and other nanozyme types due to their carbon matrix. This review comprehensively examines the research progress of carbon-based nanozymes. It details their classification into carbon nanozymes (e.g., fullerenes, graphene, carbon dots, nanotubes), heteroatom-doped carbon-based nanozymes (N, P, S, Se), and metal/metal oxide-supported carbon-based nanozymes (including single-atom nanozymes with M-Nx-C sites). The primary catalytic mechanisms, focusing on peroxidase (POD)-like and superoxide dismutase (SOD)-like activities, alongside oxidase (OXD)-like and catalase (CAT)-like mechanisms, are discussed. Strategies for regulating nanozyme performance, such as size/morphology control, composition/structure tuning (doping, defect engineering), surface modification, biomolecular interactions, and external environment manipulation (pH, temperature), are highlighted. The review emphasizes the broad applications of carbon-based nanozymes in environmental engineering (pollutant detection/degradation), biosensing (H2O2, biomolecules, antioxidants, tumor markers), and biomedicine (antioxidant/anti-inflammatory therapy, tumor treatment, antibacterial/antiviral applications, bioimaging). Finally, it addresses existing challenges, including relatively lower activity/specificity compared to natural enzymes, limited enzyme-mimicking types, unclear atomic-scale mechanisms, synthesis control difficulties, biocompatibility/safety concerns, and the need for standardized research frameworks. This overview underscores the immense potential and future research directions for carbon-based nanozymes.