Noble metal modified ReS2 nanocavity for surface-enhanced Raman spectroscopy (SERS) analysis

Enhanced Detection of Organic Pollutants Using ReS2/ZnO/Au Ternary Surface-Enhanced Raman Spectroscopy Substrate with Multiple Charge Transfer Channels

Persistent organic pollutants pose significant environmental and health risks, highlighting the urgent need for highly sensitive sensing technologies capable of detecting trace concentrations. In this study, we synthesized a ReS2/ZnO/Au ternary surface-enhanced Raman spectroscopy (SERS) substrate via a simple hydrothermal and reduction method based on a novel strategy that leverages multiple charge transfer channels to significantly enhance SERS performance. The unique bandgap and energy level alignment of ReS2 facilitate both excitonic resonance and charge transfer transitions. Additionally, the semiconductor ZnO acts as an efficient charge transfer mediator by borrowing energy from molecular transitions. As a result of the synergistic combination of electromagnetic and chemical enhancements, the ReS2/ZnO/Au ternary substrate demonstrates excellent versatility and high sensitivity for detecting various pollutants, including rhodamine 6G (R6G), crystal violet, malachite green, and tetracycline (TC). Notably, the detection limit for TC can reach 10-10 M, with an enhancement factor as high as 2.78 × 108. Our strategy provides comprehensive insight into SERS enhancement, offering a pathway for designing sensitive and versatile SERS systems, with significant potential for monitoring and quantitative analysis of organic pollutants.

ReS2 Nanoflowers-Assisted Confined Growth of Gold Nanoparticles for Ultrasensitive and Reliable SERS Sensing

ReS₂, as a new member of transition metal dichalcogenides (TMDCs), has emerged as a promising substrate for semiconductor surface-enhanced Raman spectroscopy (SERS) due to its unique optoelectronic properties. Nevertheless, the sensitivity of the ReS₂ SERS substrate poses a significant challenge to its widespread application in trace detection. In this work, we present a reliable approach for constructing a novel ReS₂/AuNPs SERS composite substrate, enabling ultrasensitive detection of trace amounts of organic pesticides. We demonstrate that the porous structures of ReS₂ nanoflowers can effectively confine the growth of AuNPs. By precisely controlling the size and distribution of AuNPs, numerous efficient and densely packed "hot spots" were created on the surface of ReS₂ nanoflowers. As a result of the synergistic enhancement of the chemical and electromagnetic mechanisms, the ReS₂/AuNPs SERS substrate demonstrates high sensitivity, good reproducibility, and superior stability in detecting typical organic dyes such as rhodamine 6G and crystalline violet. The ReS₂/AuNPs SERS substrate shows an ultralow detection limit of 10^-10 M and a linear detection of organic pesticide molecules within 10^-6-10^-10 M, which is significantly lower than the EU Environmental Protection Agency regulation standards. The strategy of constructing ReS₂/AuNPs composites would contribute to the development of highly sensitive and reliable SERS sensing platforms for food safety monitoring.