Graphene Oxide/Gold Nanorod Nanocomposite for Stable\nSurface-Enhanced Raman Spectroscopy

Abstract

We\nintroduce a graphene oxide/gold nanorod nanocomposite as a surface-enhanced\nRaman spectroscopy (SERS) substrate that suppresses the usual temporal\nintensity fluctuations, commonly referred to as blinking. The temporal\nstability of the SERS spectra from the nanocomposite is statistically\ndetermined using the coefficient of variation of the integrated spectra.\nWe demonstrate that, by introducing graphene oxide, the coefficient\nof variation from the nanocomposite is five times smaller when compared\nto gold nanorods without graphene oxide, which is attributed to the\nremoval of the nanorod’s surfactant from plasmonic hot spots\ndue to graphene oxide–surfactant interaction. The resulting\nnanocomposite can, then, be used as a reliable substrate for precise\nSERS chemical analysis. The nanocomposite is, therefore, analyzed\nas a SERS substrate for the detection of Rhodamine 640, providing\na 4-fold stability improvement relative to gold nanorods without graphene\noxide, while the dye’s Raman signal is enhanced both by SERS\nand by resonant excitation.