A quantitative study of the intracellular dynamics of fluorescently labelled glyco-gold nanoparticles via fluorescence correlation spectroscopy

The dynamic behaviour of gold nanoparticles functionalised with glucose (Glc-Au NPs) has been studied here by means of fluorescence correlation spectroscopy (FCS). Meaningful data on the state of aggregation and dynamics of Glc-Au NPs fluorescently-labelled with HiLyte Fluor647 (Glc-Au-Hi NPs) in the intracellular environment were obtained. Moreover, the work presented here shows that FCS can be used to visualise the presence of single NPs or NP aggregates following uptake and to estimate, locally, NP concentrations within the cell. FCS measurements become possible after applying a "prebleaching" methodology, when the immobile NP fraction has been effectively removed and thus significant FCS data has been recorded. In this study, Glc-Au-Hi NPs have been incubated with HepG2 cells and their diffusion time in the intracellular environment has been measured and compared with their diffusion value in water and cell media. The dynamic behavior of gold nanoparticles functionalized with glucose is studied by means of fluorescence correlation spectroscopy (FCS). Meaningful data on the state of aggregation and dynamics of these nanoparticles in the intracellular environment are obtained. FCS measurements become possible after applying a "prebleaching" methodology when an immobile fraction of NPs is effectively removed and thus allowing significant FCS data to be recorded.