Fig. 2
To compare pH-responsive polymer-coated PtMn-1, PtMn-2, or PtMn-3 (R-PtMn-1, R-PtMn-2, or R-PtMn-3) for best catalytic activity and MRI ability. a Schematic illustration for the synthetic process and property comparison of R-PtMn-1, R-PtMn-2, and R-PtMn-3. b The percentage of Mn content in three PtMn particles (n = 3). c The release percentage of Mn ions from uncoated PtMn-1, PtMn-2, or PtMn-3 particles (n = 3). d Enhancement ratio of oxidase catalytic activity: the absorption of TMBox at 650 nm (pH X/pH 7.4), calculated from Additional file 1: Fig. S6 (n = 3). Absorption spectra of TMBox incubated with R-PtMn-1 (e), R-PtMn-2 (f), or R-PtMn-3 (g) in HEPES buffer (pH = 6.0) at different incubation times. h 1/T1 or i 1/T2 of R-PtMn-1, R-PtMn-2, and R-PtMn-3 at the same total concentration in HEPES buffer with different pH values (n = 3). j Zeta potential for Nr-PtMn-1 or R-PtMn-1 in different pH values (n = 3). k, l Release profile of metal ions from R-PtMn-1 incubated in different pH values. k Mn or l Pt ions (n = 3). m The percentage of GSH-consumed for R-PtMn-1 in different pH conditions for different incubation times (n = 3)