Fig. 8

Steady state kinetic measurement and catalytic mechanism of GO/PtNPs (a–d). a Relationship diagram between initial velocity and TMB concentration; c Relationship diagram between initial velocity and H₂O₂ concentration; b, d Catalytic kinetic fitting diagram of GO/PtNPs activity when one substrate (H₂O₂ or TMB) concentration is fixed and the other substrate concentration changes. Reaction condition: a, b GO/PtNPs 0.047 μg/mL, H₂O₂ 0.02 M, TMB 0.001, 0.005, 0.01, 0.02, 0.1, 0.3, 0.5, 1.0, 1.5 mM, pH = 5, t = 5 min, λ = 652 nm (c,d) GO/PtNPs 0.047 μg/mL, H₂O₂ 0.005, 0.01, 0.015, 0.02, 0.025, 0.03, 0.035, 0.04 M, TMB 0.02 mM, pH = 5, t = 5 min, λ = 652 nm