Libin Yang

This Perspective commemorates 50 years of surface-enhanced Raman scattering (SERS) by highlighting the paradigm shift toward rationally designed semiconductor substrates, enabling ultrasensitive and molecule-selective detection. Several enhancement strategies have been developed to effectively modulate the electronic band structure and charge transfer (CT) processes, such as energy level customization, amorphization, quasi-metallization, and morphology control, achieving high enhancement factors with good selectivity and stability. Moreover, semiconductor SERS substrates show broad prospects in the fields of bio-sensing and cancer diagnosis. Nevertheless, standardization gaps in substrate reproducibility and data comparability hinder its widespread adoption. Resolving these challenges through multi-stakeholder collaboration is essential to bridge the technology transfer gap and establish SERS as a core platform for next-generation inspection.

Constructing function-customized semiconductor heterostructures is an effective strategy for developing non-noble metal surface-enhanced Raman scattering (SERS) matrixes and also provides potential opportunities for developing specific multifunctional platforms. Here, a 0D/2D TiO₂/Ti₃C₂ MXene heterojunction with hot electron excitation and high-efficiency carrier separation was successfully constructed for boosting semiconductor SERS. The enhancement factor of the SERS matrix is as high as 5.57 × 10⁹, which is currently the highest sensitivity of semiconductor substrates. Theoretical calculations and experiments reveal the contribution of charge transfer mechanisms to SERS enhancement. High carrier utilization rate contributed by hot electron excitation of Ti₃C₂ and high carrier separation efficiency induced by interface heterostructure are together responsible for the observed huge SERS enhancement. Meaningfully, the TiO₂/Ti₃C₂ matrix can serve as a sensing platform for monitoring PPCP pollutants (pharmaceuticals and personal care products) in real environment and can also be used as a photocatalytic platform for their efficient degradation. This work provides an idea and perspective for developing ultrasensitive semiconductor SERS matrixes and also provides a guidance for developing specific multifunctional platforms, ultimately promoting practical application of SERS technology in its own and other fields.

Combined contribution of electromagnetic and chemical effects and their synchronous tuning are an effective strategy for constructing semiconductor surface‐enhanced Raman scattering (SERS) substrates with ultra‐high sensitivity. In this work, a sulfur vacancy‐rich MoS₂ flower‐like microsphere is successfully prepared for the first time through the combination of morphology regulation and defect engineering strategies, achieving a synchronous contribution of electromagnetic and chemical effects to SERS enhancement. SERS enhancement factor is as high as 2.54 × 10⁸, which represents the highest sensitivity among the currently reported semiconductor SERS‐active substrates. The theoretical calculations and experiments elucidate the observed enhancement activity and the synchronous enhancement mechanism of electromagnetic and chemical effects. The unique flower‐like structures of MoS₂ can induce Mie resonance by multiple reflection and scattering of incident light in the cavity structure, which realizes a strong electromagnetic enhancement effect. Meanwhile, a high‐efficient carrier separation in substrate and a multiple‐channel charge transfer mode between substrate and analyte can be achieved by means of abundant surface sulfur‐vacancy defects, which provide a strong chemical enhancement effect for target analyte. This work opens up a new idea and perspective for constructing supersensitive semiconductor SERS sensors, ultimately advancing practical application of semiconductor SERS technology.