In Situ Analysis Of Gold Nanoparticles In Living Cells By Fluorescent Correlation Spectroscopy

Based on the fluorescent properties of gold nanoparticles,we used them as fluorescent probes to develop methods for the concentration determination of gold nanoparticles in solution and in situ analysis of gold nanoparticles in living cells by using fluorescent correlation spectroscopy.We Mainly focused on the following two aspects of work.(1)A new method for the determination of gold nanoparticle concentration in solution was established based on fluorescent correlation spectroscopy.GNPs with different particle sizes were used as model samples.By optimizing the detection time and the laser intensity,we found that the fluorescence intensity emitted by GNPs was sufficient to be detected by the fluorescent detector.So the concentration of GNPs could be measured by its weak fluorescence.At the same time,the relationship between the number of particles in the detection region and the concentration of GNPs was studied,and a good linearity was found between them.Compared with UV-vis,the results of the two methods are almost the same,which shows that the FCS method is accurate and reliable to determine the concentration of gold nanoparticles in solution with sizes between 30 nm and 50 nm.FCS method can be used for the direct determination of GNPs in solution,and the required sample volume is small,which makes it possible to determine the concentration of gold nanoparticles in living cells.(2)A new method for the in-situ determination of intracellular concentration of gold nanoparticles was established by combining fluorescent correlation spectroscopy with confocal laser scanning microscopy.After optimization of the particle size and modification scheme of fluorescent gold nanoparticle probes,we used fluorescent probe GNPs for imaging analysis of living cells based on the anti-bleaching of gold nanoparticles and auto-bleaching of cells.On the basis of imaging analysis,we used the FCS method to analyze the parameters of G(0),?_D and other parameters to obtain the concentration and diffusion time of GNPs in living cells and compare them with the results of transmission electron microscopy.This method can help people to better understand the state of the gold nanoparticles in the cell,and can be extended to other nanomaterials that can emit fluorescence,which can help people to design reasonable nanoparticles so as to promote the progress of life science.