Facile synthesis of Ag/GO SERS composite with highly sensitive and stable performance

The composite structure composed of GO and Ag has better sensing ability and is widely used as SERS substrates. However, there are few studies on the influence of external environment such as light on the stability of GO and Ag composite structure. In fact, GO can effectively prevent Ag from oxidation, so it is necessary to deeply study the mechanism of GO protection. In view of this, we prepare Ag microspheres on glass slides by one-step reduction method, and spin-coated with GO as surface enhanced Raman scattering (SERS) strips for the detection of organic molecules R6G. The detection limit is as low as 10-12 M. The linearity of the detection results is significantly corrected by using the GO characteristic peak as the internal standard (IS). The effects of xenon lamp simulate sunlight irradiation on the SERS performance of Ag substrate and Ag/GO Raman strips are investigated comparatively. We find that the Ag/GO composite structure can maintain good stability without the influence of light compared to the Ag substrate. We discuss the dynamic variation of Ag and Ag/GO substrates during the light exposure. Bacterial inhibition experiments further demonstrate the protective effect of GO on Ag. The conclusions of this paper have potential applications for improving the stability of SERS substrates.

Automated summary

The composite structure of GO and Ag is widely used as SERS substrates due to its superior sensing ability. However, the influence of external environment, such as light, on the stability of this composite structure is not well-studied. In this study, we prepared Ag microspheres on glass slides and spin-coated them with GO as SERS strips for the detection of organic molecules R6G. The Ag/GO composite structure showed better stability under light irradiation compared to Ag substrate, and GO was found to effectively protect Ag from oxidation.