Single-molecule surface-enhanced Raman spectroscopy of 4,4 '-bipyridine on a prefabricated substrate with directionally arrayed gold nanoparticle dimers

摘要

In this study, single-molecule detection on a prefabricated substrate through surface-enhanced Raman spectroscopy (SERS) with 4,4'-bipyridine molecules was achieved. The use of a substrate with directionally arrayed gold nanoparticle dimers was proposed for the single-molecule detection and identification of a wide range of bio/chemical molecules. Around 50 Raman measurements and statistical analyses were performed to demonstrate a single-molecule SERS. At 10%(-11) M, the distribution was fitted by three Gaussian curves, whereas the distribution of Raman intensities was fitted by one Gaussian curve at 10%(-5) M. The probability of molecule detection is consistent with the Poisson distribution. This result indicates the possibility of detecting 0, 1, and 2 molecules. Thus, we confirmed that the developed substrates achieved single-molecule SERS detection and identification. (C) 2017 The Japan Society of Applied Physics.