Fig. 2: H₂O₂, and ‧OH generation from Au/CuO nanocubes.

a UV–Vis profile derived from the colorimetric analysis showing the change of absorbance with Cu, Au, and different Au/Cu⁰ nanocubes (the inset showing the response of H₂O₂ given the change of colloidal color). (One representative data was shown from three independently repeated experiments). b The quantitative analysis by the response of H₂O₂ for Cu, Au, and Au/Cu⁰ nanocubes determined the absorbance intensity at 525 nm. c The quantitative analysis by the response of H₂O₂ in KMnO₄ only (blank) or KMnO₄ with Au_0.02Cu_0.98 at 525 nm absorbance under N₂ as a function of time (inset showing colloidal color after 7-day incubation). d Quantitative detection of H₂O₂ production yield from hydrogen peroxide assay kit showing fluorescence emission (λ_em = 510 nm) after reaction with Cu, Au, and Au/Cu⁰ nanocubes. e The quantitative analysis by the response of H₂O₂ in Au_0.02Cu_0.98 as a function of time and concentration. f The •OH generation detected by the fluorescence emission (λ_em = 425 nm) using terephthalic acid (TPA) probe under different pH values. g The quantitative analysis of •OH generation in Au_0.02Cu_0.98 by the fluorescence intensity at 425 nm under different concentrations at pH 5.5. h The 1:2:2:1 amplitude with quartet ESR signals of DMPO–OH associated with •OH from Cu, Au, and different Au/Cu⁰ nanocubes. All data were obtained in triplicate (n = 3, the error bars represented mean ± SD, p-values were calculated by one-way ANOVA. Source data are provided as a Source Data file).