UV-Catalyzed TiO₂–Based Optofluidic SERS Chip for Three Online Strategies: Fabrication, Detection, and Self-Cleaning

Abstract

We developed an optofluidic surface-enhanced Raman scattering chip capable of online fabrication, online molecular detection, and online self-cleaning. In this chip, we harnessed UV light to successfully reduce an AgNO₃ solution, resulting in the formation of Ag nanoparticles on carbon fiber cloth coated with titanium dioxide (TiO₂). This innovative approach enabled the online fabrication of AgNPs@TiO₂-CFC SERS structures. By introducing target molecules into our optofluidic SERS chip, we achieved online molecular Raman detection. Furthermore, by leveraging the UV light-induced self-cleaning properties of TiO₂, we achieved continuous online self-cleaning of the molecules. To verify the feasibility and stability of our method, we conducted multiple experiments for online detection and self-cleaning. Experimental results demonstrated impressively low detection limits of 10^-8 mol/L for crystal violet and 10^-9 mol/L for rhodamine 6G, with an enhancement factor as high as 1.4 × 10⁶. Additionally, we successfully applied our method to polycyclic aromatic hydrocarbons like pyrene.