Fig. 3
Catalytic efficiency and self-propulsion of Au-Pt@ur NPs. (a) Comparative analysis of the catalytic activity of free urease and urease immobilized on Au-Pt@ur NPs. (b) Comparative analysis of the catalase-like activity of different NPs, indicated by the residual H2O2 after 20-min catalyzation. (c) Representative 20-second tracking trajectories of Au-Pt@ur NPs under different stimulations. (d) Average MSD versus time interval (Δt) analyzed from tracking trajectories, showing MSD curves of individual Au-Pt@ur NPs at varying urea concentrations and with or without 3.2 mM H2O2. (e) Diffusion coefficient values extracted from the linear regression of average MSD plots (for panels c-d, 30 nanoparticles were analyzed, and the error bars in panel e represent the standard error of mean, N = 30). (f) MSD curves of Au-Pt@ur NP at different urea concentrations. (g) Diffusion coefficient values extracted from the linear regression of average MSD plots (for panels f, 30 nanoparticles were analyzed, and the error bars in panel g represent the standard error of mean, N = 30)