Proceedings Article | 1 November 2021
KEYWORDS: Raman spectroscopy, Surface enhanced Raman spectroscopy, Nanoparticles, Silver, Molecules, Imaging spectroscopy, Nanomaterials, Nanoprobes, Signal detection, Absorption
Anisotropic plasmonic gold nanorods (AuNRs) not only have excellent electrical conductivity and electrocatalytic activity, due to localized surface plasmon resonance, they also have good optical properties, such as tunable UV-vis-NIR absorption and so on. Therefore, AuNRs have very high potential in sensing, catalysis, and theranostics. In this contribution, we synthesized AuNR@Ag core-shell metallic nanostructures, with 1,4-benzenedithiol (1,4-BDT) sandwiched between the Au-Ag gaps. To the outside of the covering silver layer, 4-Mercaptopyridine (4-MPY) is attached to give a second Raman signal and a layer of BSA coating is applied for further stability. The nanocomposite is used for cell imaging, whereas the Raman signal from the 4-MPY is used to monitor the effects of the subcellular organelles on the engulfed nanomaterials. Our results show that as the thickness of the silver shell layer increases, the BDT Raman signal intensity gradually increases. When the silver layer thickness exceeds a certain value, the increase in the silver layer thickness will cause the surface enhanced Raman scattering (SERS) signal intensity to drop. And as 4-MPY is embedded on the outside of the silver layer, the Raman spectrum of the entire material adds three new Raman peaks at 428 cm-1 , 707 cm-1 , and 1000 cm-1 , respectively. The changes in these peaks can be used to probe the interactions between cells and the nanomaterials. In addition, the combination of dark-field imaging and Raman spectroscopy for the analysis of the nanomaterial-cell interaction indicates that the SERS nanoprobe can indeed explore the interactions between the cells and nanomaterials. Therefore, these results indicate that the nanoprobe is a cell trace analysis tool with important application prospects.
