fig12

Figure 12. TMD-based SERS. (A) schematic illustration of SERS detection on defect-engineered monolayer MoS₂; (B) comparison of Raman spectra and density of states between pristine and defect-rich MoS₂. (A and B) are adapted with permission^[31]. Copyright 2022, MDPI.; (C) representative SEM images of vertically and horizontally oriented MoS₂ nanostructures; (D) SERS spectra of bilirubin on vertical MoS₂/Si substrates. (C and D) are adapted with permission^[32]. Copyright 2023, Royal Society of Chemistry; (E) electrochemically modulated band diagram illustrating tunable photon-driven charge transfer in MoS₂-based EC-SERS systems, adapted with permission^[40]. Copyright 2024, Elsevier; (F) combined single-molecule SERS mapping images at ultralow concentrations (10^-15 to 10^-19 M); (G) DFT electron-density maps comparing pristine and nanopore-engineered WS₂, revealing the atomic-scale origin of the enhanced charge-transfer mechanism. (F and G) are adapted with permission^[41]. Copyright 2025, American Association for the Advancement of Science. CB: conduction band; VB: valence band; HOMO: highest occupied molecular orbital; LOMO: lowest occupied molecular orbital.