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.