Single Molecule SERS with Directionally Arrayed Gold Nanoparticle Dimers on Substrate

摘要

This study achieved single molecule detection, for the first time, on the prefabricated substrate for SERS (surface-enhanced Raman spectroscopy) with non-resonant molecules. Single-molecule SERS has never been achieved using the prefabricated SERS substrate. It has been achieved only using molecule bridged particle dimer by in-liquid formation with polarization matching of incident light. In this study the substrate with directionally arrayed gold nanoparticle dimers was proposed for single molecule detection and identification of a wide range of bio/chemical molecules. Around 50 Raman measurements and statistical analysis were performed for demonstrating single-molecule SERS. At 10~(-5) M, the distribution of Raman intensities were fitted by one Gaussian curve. At 10~(-11) M, the distribution was fitted by three Gaussian curves. That is consistent with a Poisson distribution. This indicates the probability of detecting 0, 1, and 2 molecule(s). From these results, we confirmed that the developed substrates achieved single molecule SERS detection and identification.