Fig. 2.

Characterization of MPG NPs. A Synthesis of MPG NPs. B TEM of Mn₃O₄ NPs. C TEM of Mn₃O₄@PDA NPs. D XRD spectrum of Mn₃O₄ NPs. E UV absorption spectra of Mn₃O₄@PDA NPs, T, Mn₃O₄@PDA-T NPs, T-GMBP1, and MPG NPs. F Fluorescence spectrum of T-GMBP1 and MPG NPs. G The size of Mn₃O₄@PDA NPs, Mn₃O₄@PDA-T NPs and MPG NPs. H The zeta potential of Mn₃O₄@PDA NPs, Mn₃O₄@PDA-T NPs and MPG NPs. I The size change of MPG NPs in different solvents at different temperatures