Fig. 5

Catalysis and stability of ZnS–Au SPs for photoinduced oxidative coupling of l-Tyr and d-Tyr. Fluorescence spectra of l-Tyr or d-Tyr after a l-Tyr with l-ZnS–Au SPs, b d-Tyr with l-ZnS–Au SPs being illuminated with different periods of time in the presence of ZnS–Au SPs. c Extracted ion chromatography (EIC) of l-Tyr and Tyr-related products of l-ZnS–Au SP l-Tyr samples obtained at 0, 18, and 32 h, m/z = 405.10, 383.12, and 361.14, and m/z = 242.04, 220.06, and 198.08 are attributed to DOPA-Na + Na⁺, DOPA + Na⁺, and DOPA + H⁺ and diTyr-Na + Na⁺, diTyr + Na⁺ and diTyr + H⁺, respectively. d The dependence of PL intensity at 306 nm on photocatalytic reaction time with l-ZnS–Au SPs for different Tyr enantiomers. e CD spectra of the mixtures of ZnS and Au NPs, ZnS–Au SPs, after UV illumination (115 V, 50/60 Hz, 0.16 A) for different times