Preparation of Different Lights Irradiated ZnSe/ GSH QDs and Their Interaction with BSA

Using L-glutathione (GSH) as a capping agent, ZnSe/GSH quantum dots (QDs) were prepared under microwave irradiation and irradiated under dark, ultraviolet light and incandescent light, respectively. The properties and interaction of different lights irradiated ZnSe/GSH QDs and bovine serum albumin (BSA) were studied systematically. The fluorescence (FL) spectra results reveal that the quenching mechanism are all the static quenching in nature. The quenching constant (Ksv) and binding constant (K) value of different irradiated ZnSe/GSH QDs and BSA all increased with the change of light types from dark to incandescent light and UV light. The number of binding site (n) is close to 1 at different temperatures. The lighting types influence the enthalpy and entropy changes. The Fourier transform infrared (FTIR) spectra indicate that the light induced GSH ligand will facilitate photocatalytic oxidation on the surface of ZnSe/GSH QDs. The circular dichroism (CD) results show that the α-helicity content of BSA decreases from 60.34%, 59.31%, to 58.79% under UV lighting, incandescent lighting and dark conditions. The interaction results of different lights illuminated ZnSe/GSH QDs with BSA by CD spectra method matches well with that by FL and FTIR spectra. That is, the interaction of ZnSe/ GSH QDs and BSA from strong to weak is UV light, incandescent light and dark in sequence.