Sulfur Vacancies‐Triggered High SERS Activity of Molybdenum Disulfide for Ultrasensitive Detection of Trace Diclofenac

Abstract

AbstractDue to the efficient photoinduced charge transfer properties of nonmetals, nonmetallic surface‐enhanced Raman scattering (SERS) substrates have been advanced rapidly these years. And among of these, molybdenum disulfide (MoS2) is perceived as one of the most representative nonmetallic SERS substrates due to its abundant active sites. However, its progress in SERS field is severely hindered because of the lower SERS activity. Herein, one type of vacancies‐triggered highly sensitive SERS substrate based on nanostructured MoS2 with sulfur vacancies (VS) is proposed. The VS‐MoS2 substrates are intended to promote the SERS performance through the VS density regulation. Intrinsically, moderate VS can change the bandgap structure of MoS2, thus promoting the separation of internal carriers and enhancing the interaction with target species. Externally, the presence of VS can bring abundant adsorption sites on MoS2 surface, which greatly improves its ability to enrich target molecules. Both internal and external properties make VS‐MoS2 a high SERS activity substrate. Moreover, with the antibiotic contaminant diclofenac as a model probe molecule, the VS‐MoS2 substrate can accurately perceive its nanomolar concentration level with an enhancement factor up to 5.85 × 103. This work demonstrates exciting potential for analysis in real water environments based on nonmetallic SERS applications.