Synthesis Of Gold Nanocluster-loaded Phospholipid Micelles And Its Application In Detection Of Hypochlorous Acid

Gold nanoclusters(Au NCs)are composed of a few to hundreds of gold atoms that aggregated under the protection of ligand molecules.Typically,the metal core size of Au NCs is less than 3 nm.The ultrasmall size of gold nanoclusters is close to the Fermi wavelength of electrons,which makes the movement of electrons extremely restricted,leading to the splitting of the continuous energy level of gold nanomaterials into discrete energy levels.Therefore,Au NCs exhibit many molecules-like properties,among which the luminescent properties are of particular interest.Because of the advantages such as good photostability,large Stokes shift,and long luminescence lifetime,Au NCs have shown promising applications in bioanalysis and bioimaging.They have been successfully applied in the analysis and imaging of multiple biomolecules.However,there are still some deficiencies in their application,mainly in their poor stability in biological systems.Au NCs are prone to be interfered and etched by other substances in the environment,such as biological sulfhydryl molecules.Based on these,we synthesized micelles encapsulated with Au NCs using amphiphilic polymers,which have good optical properties and stability for bioanalysis.The main research contents include the following:(1)We first synthesized luminescent gold nanoclusters(PET-Au NCs)by using phenylethanethiol(PET)as ligands and sodium borohydride as reducing agent.Then amphiphilic polymer(DSPE-PEG)was utilized to form stable micelles in the aqueous phase for the encapsulation of luminescent Au NCs.The resulting micelles encapsulated with PETAu NCs exhibited good stability and exhibited anti-biological etching of thiol molecules.(2)To further improve the luminescent properties of Au NCs and enhance the sensitivity for their analytical applications,based on the phenylethanethiol stabilized gold nanoclusters(PET-Au NCs),We further synthesized benzyl mercaptan(BM)stabilized luminescent gold nanoclusters(BM-Au NCs)with obvious aggregation-induced luminescent properties.After encapsulation of BM-Au NCs using DSPE-PEG forming micelles,DSPE-PEG-BM-Au NCs were not only able to effectively resist the etching of biological sulfhydryl molecules but also exhibited obviously improved luminescence performance based on the aggregation-induced luminescence effect.(3)The DSPE-PEG encapsulated BM-Au NCs can be used as a nanoprobe for the detection of HCl O with good performance.The luminescence of Au NCs was effectively and selectively quenched by HCl O.A good linear relationship with the concentration of HCl O in the range of 5?35 ?M and a limit of detection(LOD)of 1.4 ?M were obtained.Additionally,this nanoprobe was successfully used for bioimaging and monitoring of HCl O changes in live cells,suggesting the as-prepared micelles encapsulating gold nanoclusters had certain practical values in biosensing and bioimaging.