Catalytic properties of a nanozyme based on silver nanoparticles immobilized in a polymethacrylate matrix

This article presents studies on the catalytic, peroxidase-like properties of silver nanoparticles (Ag NPs) immobilized in polymethacrylate matrix (PMM). Ag NPs were prepared by thermal reduction of silver cations pre-immobilized in PMM. The morphology of the nanocomposite was studied using scanning electron microscopy, and the average size of the synthesized individual spherical nanoparticles was 18 ± 5 nm. It was demonstrated that silver nanoparticles immobilized in a polymethacrylate matrix (PMM-Ag⁰) exhibit pronounced peroxidase-like activity in the oxidation reaction of the chromogenic substrate – indigocarmine in the presence of H₂O₂. The Michaelis–Menten model was used to assess the kinetic parameters of the reaction. The values of Michaelis constant (Km) observed for indigocarmine and H₂O₂ (0.1 mM and 1.0 mM, respectively) show strong affinity of the substrates to silver nanoparticles in PMM.