Analysis of Intracellular State Based on Controlled 3D Nanostructures Mediated Surface Enhanced Raman Scattering

Abstract

Near-infrared surface-enhanced Raman spectroscopy (SERS) is a powerful technique for analyzing the chemical composition within a single living cell at unprecedented resolution. However, current SERS methods employing uncontrollable colloidal metal particles or non-uniformly distributed metal particles on a substrate as SERS-active sites show relatively low reliability and reproducibility. Here, we report a highly-ordered SERS-active surface that is provided by a gold nano-dots array based on thermal evaporation of gold onto an ITO surface through a nanoporous alumina mask. This new combined technique showed a broader distribution of hot spots and a higher signal-to-noise ratio than current SERS techniques due to the highly reproducible and uniform geometrical structures over a large area. This SERS-active surface was applied as cell culture system to study living cells in situ within their culture environment without any external preparation processes. We applied this newly developed method to cell-based research to differentiate cell lines, cells at different cell cycle stages, and live/dead cells. The enhanced Raman signals achieved from each cell, which represent the changes in biochemical compositions, enabled differentiation of each state and the conditions of the cells. This SERS technique employing a tightly controlled nanostructure array can potentially be applied to single cell analysis, early cancer diagnosis and cell physiology research.

Thin nanoporous alumina-based SERS platform for single cell sensing

“…For example, successful applications of SERS as a tool for in vitro studies have been obtained in targeting tumor cells with metal nanoparticles (mNPs) [21][22][23][24]. However, the requirement of antibody-conjugated mNPs implies several technological difficulties, such as non-specific bonding, interferences from the antibody and toxic effects on the cells [25,26]. In this perspective, we believe that the approach involving cells seeded on plasmonic substrates represents a valid alternative option [18,24,26].…”

“…However, the requirement of antibody-conjugated mNPs implies several technological difficulties, such as non-specific bonding, interferences from the antibody and toxic effects on the cells [25,26]. In this perspective, we believe that the approach involving cells seeded on plasmonic substrates represents a valid alternative option [18,24,26]. In nanostructured metal surfaces the analyte interacts with the metallic nanostructure or nanoparticles clusters at the surface, where SERS ‗hot spots' are formed.…”

A simple and rapid detection of tissue adhesive-induced biochemical changes in cells and DNA using Raman spectroscopy

“…Raman spectroscopy has attracted great interest as a powerful analytical tool that can be used to detect changes in the structure and composition of analytes at the molecular level [6][7][8][9][10]. It also provides quantitative information, together with high sensitivity and selectivity.…”

Investigation of biochemical property changes in activation-induced CD 8 + T cell apoptosis using Raman spectroscopy

“…Raman spectroscopy has attracted great interest as a powerful analytical tool for detecting changes in the chemical structure and composition of a substance at the molecular level [10][11][12] together with high sensitivity and selectivity. This technology has several additional advantages in that it is noninvasive, allows for rapid detection and does not require the use of labels to study biologically relevant molecules.…”