Controllable Preparation And Application Of Fluorescent Functional Gold Nanoclusters

As a new type of fluorescent nanomaterials,metal nanoclusters have a size similar to the Fermi wavelength of electrons.Their properties are between single atoms and larger nanoparticles.They exhibit a size-dependent effect like molecules,so they have unique characteristics and optical properties.Compared with metal nanoclusters,traditional phosphors have many shortcomings.For example,the synthetic precursors required for semiconductor quantum dots are basically highly toxic,and the preparation process is strict and complicated,and the cost is relatively high.Although organic dyes do not have the aforementioned shortcomings of semiconductor quantum dots,they have a short fluorescence lifetime and unstable properties.Gold nanoclusters have unique chemical and optical properties,such as strong fluorescence emission,ultraviolet-visible light absorption,and solvation effects.In summary,the gold nanoclusters can be used as fluorescent probes with good performance.In today's society,cancer has become the highest death rate of the disease,the world health organization shows that the number of people dying from cancer is increasing every year,it has seriously threatened human health.How to realize the early diagnosis and treatment of malignant tumor in clinic will become the focus of research.The early diagnosis of malignant tumor can be realized by fluorescence labeling of biological imaging.Fluorescently labeled probes should have excellent properties such as high sensitivity,low biotoxicity,good biocompatibility and fluorescence stability,which are essential factors for specific labeling of tumor cells.Using noble metal nanoclusters,fluorescent nanocomplexes and other nanomaterials as fluorescent labeled probes has become a hot topic for researchers.In this paper,folic acid was first used to interact with bovine serum albumin and then to react with chlorauric acid to form gold nanoclusters.Gold nanoclusters were incubated with cells,and fluorescence confocal imaging of ges-1 cells and Hela cells was conducted.Observation by laser confocal microscope shows that the prepared FA-BSA/Au NCs can be quickly absorbed by tumor cells in a short time and play a role in fluorescent labeling,while normal cells are difficult to observe fluorescent labeling phenomenon even after a long time.The research results show that the preparation of fluorescent gold nanoclusters protected by bovine serum albumin by a simple hydrothermal synthesis method can quickly and specifically identify tumor cells under the action of the targeting agent folic acid,and the strong fluorescence imaging effect is good.Based on the above research,it can be found that FA-BSA/Au NCs have a good bio-fluorescence specific labeling function,and great application value in clinical early diagnosis of cancer.In addition,gold nanoclusters fluorescent probes also play an important role in environmental detection and other fields.We also studied the detection of metal ions by gold nanoclusters protected by bovine serum albumin.The study found that mercury ions can quench the gold nanoclusters protected by bovine serum albumin.Based on this phenomenon,gold nanoclusters were used as fluorescent probes to detect inorganic mercury ions through sample analysis experiments,sensitivity experiments,and selectivity experiments.Based on the phenomenon that mercury ions can quench the fluorescence of BSA-Au NCs,we combined BSA-Au NCs with polyvinyl alcohol(PVA)to prepare BSA-Au NCs/PVA composite membranes for the detection of mercury ions.