| At present,many people are interested in the preparation and application of fluorescent and chiral silver nano-clusters(AgNCs),and have done a lot of research.However,many synthetic methods of AgNCs need to be further improved,and the mechanism of fluorescence enhancement of AgNCs is not sufficiently studied.There are few reports on using AgNCs fluorescence characteristics for chiral analysis,and the related research needs further exploration.Therefore,the preparation,characterization and chiral recognition of fluorescent chiral AgNCs have been studied in this paper.1.In this paper,we have successfully prepared AgNCs with both chiral and fluorescence by the method of solid phase synthesis with the use of glutathione((±)GSH)as a ligand.Silver nitrate(AgNO3)and GSH solid were thoroughly mixed and reduced by sodium borohydride(NaBH4),and the solid mixture was purified to give AgNCs with chirality.AgNCs were further incubated with water for 24 h to obtain AgNCs with both fluorescence and chirality.The conditions of AgNCs preparation temperature,ligand ratio,oxygen,solvent polarity and solvent pH were optimized.2.The experiment was further studied by fluorescence(FL),high resolution transmission electron microscopy(HR-TEM),Fourier transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),circular dichroism(CD)spectroscopy and electrospray ionization mass spectrometry(ESI-MS)were used to characterize the synthesized AgNCs.The results showed that the fluorescent chiral AgNCs were successfully synthesized by the solid-phase method and Ag(I)was not present.The particle size of the AgNCs is 1.68 nm,which is mainly composed of Ag4(SG)4.More interestingly,it was found that the fluorescence of AgNCs was significantly enhanced and the CD signal changed significantly during the incubation.3.In order to study the AgNCs aggregation induced fluorescence enhancement(AIEE)characteristics and chiral change,a series of experiments including matrix assisted laser desorption / ionization time of flight mass spectrometry(MALDI-TOF-MS),fluorescence(FL)and CD spectra were used in the study.It was found that the formation of hydrogen bond between GSH caused the cross-linking polymerization of AgNCs,which led to the appearance of AIEE and chiral changes.4.The prepared AgNCs can be applied to the detection of D/L-penicillamine(D/L-LPA),D/L-glucose(D/L-Glu)and D/L-histidine(D/L-His).In this study,the prepared AgNCs are expected to be used as chiral fluorescent probes for the chiral recognition of biomolecules and drug molecules.The preparation of the chiral fluorescent AgNCs and its mechanism are studied in detail in the study of metal nanoclusters(MNCs)has special guiding significance. |
