Fig. 3

Fluorescence spectra of CAT (a, b) or SOD (d, e) in the presence of AgNPs (a, d) or Ag⁺ (b, e) at different concentrations; F/F₀ (Spectral peak) of CAT (c) or SOD (f) in the presence of AgNPs or Ag⁺ at different concentrations. (Where F₀ is the fluorescence intensity of CAT/SOD without quencher, F is the fluorescence intensity of CAT/SOD quenched by AgNPs/Ag⁺, the same as below). Condition: T = 298 K; pH 7.4; a–c \(\lambda_{ex}\) = 278 nm; C(CAT) = 5×10⁻⁷ mol/L; C(AgNPs/Ag⁺, × 10⁻⁷ g/mL), a–f 0, 4, 8, 12, 16, 20; AgNPs or Ag⁺ only: C(CAT) = 0, C(AgNPs or Ag⁺) = 20 × 10⁻⁷ g/mL; d–f \(\lambda_{ex}\) = 280 nm; C(SOD) = 6×10⁻⁶ mol/L; C(AgNPs/Ag⁺, × 10⁻⁶ g/mL), a–f 0, 4, 8, 12, 16, 20; AgNPs or Ag⁺ only: C(SOD) = 0, C(AgNPs or Ag⁺) = 20 × 10⁻⁶ g/mL