Gold Nanoaggregates For Probing Single Living Cell Based On Surface-enhanced Raman Spectroscopy

In this study, we propose to incorporate gold nanoparticles into hepatoma carcinoma cell line through transient electroporation method and analyze intracellular fingerprint information based on their surface-enhanced Raman spectroscopy (SERS). The main research results as follows:1. The cells being treated with silver nanoparticles through electroporation (less than1min) and "passive uptake" experiment (24h incubation) have significant differences in SERS spectral shapes. These spectral changes may be related to the cellular toxicity caused by incubating with silver nanoparticles for a very long time (24h).2. Gold nanoparticles are delivered into living cell by electroporation method and we obtain the mean whole-cell SERS spectra of the HepG2cells (n=15). The subcellular localization of gold nanoaggregates is essentially in the cytoplasm and they form overlapping nanoaggregates in sizes between300nm and a few micrometers. High-resolution TEM photographs and the SERS spectra from the whole-cell demonstrate that the aggregation of gold nanoparticles obtained by electroporation method contributes equal or even better SERS enhancement than that developed by "passive uptake"(24h incubation).3. The cells being treated with gold nanoparticles through electroporation (less than1min) and "passive uptake" experiment (24h incubation) have similar SERS spectral profiles. Interestingly, the cell is still in the growth and division after a long time incubation (24h) of gold nanoparticles and the cell. In this paper, we have used electroporation method for rapid delivery of gold nanoparticles into living HepG2cells to achieve intracellular SERS spectra. This new method is much faster and more efficient than "passive uptake" in delivering gold nanoparticles into cells, providing potential opportunities for the diagnosis of diseases at early stage.