Warp-Driven Dual-Side Adsorption for Superior Surface-Enhanced Raman Scattering Performance of Transition Metal Dichalcogenides Nanosheets

Surface-enhanced Raman scattering (SERS) technology is highly sensitive but limited by the high cost of noble-metal substrates and the low enhancement of two-dimensional (2D) materials. This work proposes a dual-sided adsorption strategy utilizing warped structures at the cracks and edges of WSe 2 and MoSe 2 nanosheets grown by Chemical Vapor Deposition (CVD). Driven by capillary forces, probe molecules infiltrate the nanosheet–substrate interface, enabling dual-sided adsorption on both the upper and lower surfaces. This approach enhances SERS signals by up to 20-fold, with a detection limit of 10 –10 M, surpassing most reported traditional single-sided adsorption modes. Additionally, it improves stability by isolating the probe molecules from oxygen. This study further enhanced the formation efficiency and coverage area of the dual-sided adsorption mode by leveraging wide warped structures. It offers new perspectives on the application of crack defects and the potential for the development of high-performance and highly stable SERS substrates.