Few-Layer NbTe2 Nanosheets as Substrates for Surface-Enhanced Raman Scattering Analysis

Recently, two-dimensional (2D) semiconductor materials have been the focus of substantial research interest in surface-enhanced Raman scattering (SERS) because of their fascinating and unique properties. Herein, 2D niobium ditelluride (NbTe2) nanosheets (NTNs) with the lamellar and ultrathin crystalline morphologies were easily synthesized for the first time via liquid-phase exfoliation combined with the hydrothermal method. NTNs could serve as a low-cost metal-free 2D SERS substrate for the ultrasensitive detection of aromatic molecules and antibiotics because of the fluorescence quenching effect and the charge transfer enhancement mechanism. The enhancement factor of NTNs can be up to 5.59 × 106 with expanding the ultralow limit of detection (LOD) to 10–9 M, which approached that of metal-based SERS substrates. Good reproducibility and uniformity were also acquired on the 2D substrate and facilitated the reliable SERS analysis of ciprofloxacin (CIP) and enrofloxacin (ENR) at a low concentration, which exhibited LODs of 35.1 and 35.9 ppb, respectively. The 2D SERS substrates with remarkable SERS sensitivity and specificity may pioneer the applications of telluride-based materials for food and drug safety detection.