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

We introduce a graphene oxide/gold nanorod nanocomposite as a surface-enhanced Raman spectroscopy (SERS) substrate that suppresses the usual temporal intensity fluctuations, commonly referred to as blinking. The temporal stability of the SERS spectra from the nanocomposite is statistically determined using the coefficient of variation of the integrated spectra. We demonstrate that, by introducing graphene oxide, the coefficient of variation from the nanocomposite is five times smaller when compared to gold nanorods without graphene oxide, which is attributed to the removal of the nanorod's surfactant from plasmonic hot spots due to graphene oxide–surfactant interaction. The resulting nanocomposite can, then, be used as a reliable substrate for precise SERS chemical analysis. The nanocomposite is, therefore, analyzed as a SERS substrate for the detection of Rhodamine 640, providing a 4-fold stability improvement relative to gold nanorods without graphene oxide, while the dye's Raman signal is enhanced both by SERS and by resonant excitation.