Au Nanoparticle/Graphene Oxide Composites Deposited on Au Nanorod Arrays as Substrates for Surface-Enhanced Raman Scattering Sensing
Tianran Wang, Weiye Gao, Chushu Zhu, Pengxing Sha, Yulie Wu, Xuezhong Wu, Peitao Dong
Abstract
In this study, the objective was to develop Au nanorod arrays (AuNRAs) using two-dimensional (2D) graphene oxide (GO)-supported Au nanoparticles (AuNPs). Graphene oxide (GO) and AuNPs in different ratios were prepared, and the coupling performances for AuNRAs-GO/AuNPs were studied to optimize the AuNRAs-GO/AuNP substrate using 1,2-bis(4-pyridyl)ethylene (BPE). To further prove the Raman performance of AuNRAs-GO/AuNPs, Raman molecular BPE was used to assess the uniformity of Raman signaling across the substrate. The addition of GO/AuNPs endows AuNRAs with universally high adsorption of analytes and the electromagnetic mechanism from the multidimensional couplings of AuNRAs-GO/AuNPs enhances Raman performance; therefore, the AuNRAs-GO/AuNP preparation achieves sensitivity and repeatability. The optimized substrate was then used to detect melamine. Ultrasensitive detection of melamine reached a limit of detection of 10–9 M. To demonstrate the application potential of AuNPs/GO/AuNRAs, melamine was detected in liquid milk and its limit of detection was determined to be 1 ppm, which meets the maximum limit for the melamine content in infant milk as proposed by the World Health Organization, thus revealing the application potential of our method.