Regulation of the Structural and Catalytic Properties of NiCo₂O₄ Nanozymes Using Monodisperse Cellulose Oligomers

In this study, monodisperse cellulose oligosaccharides (MCOs) were introduced as molecular scaffolds to successfully synthesize MCOs@NiCo₂O₄ composite nanozymes. Benefiting from the excellent surface modification ability and confinement effect of MCOs, the nucleation and oriented growth of NiCo₂O₄ nanozymes were effectively guided, resulting in well-defined morphology and controllable surface chemical environments. Structural characterizations revealed that the incorporation of MCOs significantly improved the dispersion and interfacial chemistry of NiCo₂O₄ nanozymes, facilitating the exposure of active sites. Catalytic performance tests demonstrated that MCOs@NiCo₂O₄ composite nanozymes exhibited higher specific enzyme activity and reaction rate in the 3, 3’, 5, 5’-tetramethylbenzidine (TMB)/H₂O₂ system. Moreover, by enhancing the catalytic rate per enzyme unit while maintaining substrate-binding ability, the overall catalytic efficiency was effectively improved. These results indicated that MCOs modification not only optimized the structural and surface properties of NiCo₂O₄ nanozymes but also enhanced its peroxidase-like activity, providing a novel design strategy and synthesis route for constructing structurally controllable and performance-tunable high-efficiency composite nanozymes.