The emerging role of semiconductor nano-photocatalysts in strengthening surface enhanced Raman scattering applicability for sustainable multifunctional applications.

Surface-enhanced Raman scattering (SERS) has emerged as a powerful analytical technique for the ultrasensitive detection of organic, inorganic, and biological molecules, with promising applications in environmental monitoring, biomedical diagnostics, and chemical analysis. Traditionally, noble metal nanostructures have served as key SERS substrates due to their localized surface plasmon resonance driven electromagnetic enhancement. However, evolving application requirements including operational durability, sustainability considerations, and economic factors have driven the exploration of complementary materials to expand and diversify SERS platform capabilities. In response, semiconductor-based nano-photocatalysts have attracted growing interest as complementary materials in SERS substrate design. These materials offer distinct advantages, including photocatalytic activity, efficient surface adsorption and self-cleaning as well as charge transfer capabilities-enhancing the SERS sensitivity, reproducibility, and structural robustness. Furthermore, they enable real-time monitoring of photocatalytic molecular transformations and reaction intermediates, contributing valuable insights into surface chemistry and charge-transfer mechanisms. Hybrid SERS substrates, combining semiconductor photocatalysts with noble metal nanostructures, provide synergistic SERS enhancement effects through the integration of electromagnetic and chemical (or charge transfer) mechanisms while also improving the optoelectronic properties and expanding the functionality in other directions. The incorporation of emerging photocatalytic materials such as UV- and visible-light-active semiconducting materials, semiconducting polymeric and two-dimensional semiconducting materials with special features/characteristics like thermoelectric, magnetic and self-cleaning properties further strengthens SERS applicability by offering greater flexibility, multifunctionality, and sustainability. This minireview highlights the emerging role of such semiconductor nano-photocatalysts in advancing SERS technology toward sustainable multifunctional applications. It discusses recent advances, current challenges, and future strategies aimed at enhancing SERS efficiency and broadening its utility in environmental, biomedical, and catalytic domains.