▎ 摘　　要

Surface-enhanced Raman scattering (SERS) as a sensitive detection method had attracted tremendous attention. Graphene quantum dots (GQDs) were synthesized by a top-down approach, and the W18O49 samples were prepared by a solvothermal method with WCl6 as the tungsten source. The size of prepared GQDs presented a size of 10 nm and a topographic height of 1.5 nm, corresponding to 1-3 layers of graphene sheets. There were two different lattice fringes of 0.34 nm and 0.378 nm matched with the (002) and (010) lattice planes of GQDs and W18O49, respectively. After the modification of GQDs, the band gap energy of W18O49 was narrowed, and the separation and electron transport capability of W18O49 were improved due to the existence of GQDs. In this work, the detection sensitivity of SERS was effectively improved by chemical and electromagnetic field enhancement when W18O49/GQDs composites were used as SERS substrates. Therefore, it will be an effective way to improve the SERS performance of W18O49 by modifying GQDs.