nanozyme

A nanozyme is a nanomaterial that exhibits enzyme-like catalytic activity. The term covers a wide range of materials that mimic natural enzymes, including peroxidases, oxidases, catalases, superoxide dismutases, and even glucose oxidase. Nanozymes are typically inorganic or carbon-based and can operate under harsher conditions and with greater stability and lower cost than many natural enzymes.

Common nanozymes include iron oxide nanoparticles with peroxidase-like activity; metal oxides such as ceria (CeO2), manganese oxides (MnO2), and vanadium oxides; noble metals like platinum and gold; carbon-based materials such as graphene oxide and carbon dots; and metal–organic frameworks. Surface engineering and compositional tuning are used to adjust activity, selectivity, and biocompatibility.

Mechanistically, nanozymes act as catalytic surfaces that mediate redox reactions. Many demonstrate peroxidase-like activity, using hydrogen peroxide to oxidize substrates; others show catalase-like, oxidase-like, or superoxide dismutase-like activities. Kinetic behavior can resemble Michaelis–Menten in some cases, though exact kinetics vary with material and substrate. Common assay platforms include colorimetric readouts (for example, TMB in the presence of H2O2).

Applications span sensing, therapy, and environmental remediation. In biosensing, nanozymes enable colorimetric, electrochemical, and chemiluminescent detection of analytes. In biomedicine, they are explored for antibacterial therapy, cancer treatment, and antioxidant or pro-oxidant approaches. Environmental uses include degradation of pollutants and catalytic treatment of wastewater.

Limitations include lower substrate specificity and catalytic efficiency compared with natural enzymes, potential toxicity and biocompatibility concerns, and reproducibility challenges. Ongoing research seeks higher selectivity, safer implementations, and integration into devices and multi-enzyme systems.