Fig. 4

Synchronous fluorescence spectra of CAT in the presence of AgNPs (a, d) or Ag⁺ (b, e) at different concentrations. F/F₀ (Synchronous fluorescence spectral peak) of CAT in the presence of AgNPs or Ag⁺ at different concentrations. Condition: T = 298 K; pH 7.4; C(CAT) = 5×10⁻⁷ mol/L; AgNPs (a)/Ag⁺ (b) only: C(CAT) = 0, C(AgNPs/Ag⁺) = 20 × 10⁻⁷ g/mL; a, b, d C(AgNPs/Ag⁺, × 10⁻⁷ g/mL), a–f 0, 4, 8, 12, 16, 20; e C(Ag⁺, × 10⁻⁷ g/mL), a–f 20, 16, 12, 8, 0, 4