Investigation of biochemical processes in single cell using surface-enhanced Raman scattering

Single cell analysis is rapidly emerging approach to gain molecular information at the individual cell level. Investigation of specific molecular mechanisms and pathways providing in single cell level is crucial. In this study, we investigated Surface-enhanced Raman scattering (SERS) to study single-cells. Gold nanoparticles (AuNPs) were used as routinely employed SERS substrate. SERS activity of AuNPs depends on size, shape and aggregation status in living cell depending on their uptake profile. We are interested in understanding the biochemical changes on AuNPs or in their aggregates to understand the possibility of monitoring cellular biochemical process in a living cell. Thus, two different sizes of AuNPs with two different surface chemistry were used in the study. The order and combination of AuNPs with different sizes and surface chemistry helped to understand the spectra obtained from a single cell and thus the nature of the biochemical processes taking place on the AuNPs surfaces. This study showed that SERS can be used for single cell analysis and its possible use in molecular biology. In this study, the spectral changes espicially correspond to protein and lipids were observed depending on size, surface chemistry, and aggregation status in time dependent manner.