Exploring and Engineering 2D Transition Metal Dichalcogenides toward Ultimate SERS Performance.

Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive surface analysis technique that is widely used in chemical sensing, bioanalysis, and environmental monitoring. The design of the SERS substrates is crucial for obtaining high-quality SERS signals. Recently, 2D transition metal dichalcogenides (2D TMDs) have emerged as high-performance SERS substrates due to their superior stability, ease of fabrication, biocompatibility, controllable doping, and tunable bandgaps and excitons. In this review, a systematic overview of the latest advancements in 2D TMDs SERS substrates is provided. This review comprehensively summarizes the candidate 2D TMDs SERS materials, elucidates their working principles for SERS, explores the strategies to optimize their SERS performance, and highlights their practical applications. Particularly delved into are the material engineering strategies, including defect engineering, alloy engineering, thickness engineering, and heterojunction engineering. Additionally, the challenges and future prospects associated with the development of 2D TMDs SERS substrates are discussed, outlining potential directions that may lead to significant breakthroughs in practical applications.