Recyclable three-dimensional Ag nanorod arrays decorated with O-g-C₃N₄ for highly sensitive SERS sensing of organic pollutants

A three-dimensional (3D) substrate was developed by assembling a monolayer of graphitic carbon nitride (O-g-C₃N₄) on Ag nanorod arrays (Ag NRs) for sensitive and recyclable surface enhanced Raman scattering (SERS) detection. The prepared Ag NRs/O-g-C₃N₄ substrate not only generated a significant Raman enhancement effect as a result of the strong π-π stacking interaction between O-g-C₃N₄ and the analytes but also possessed excellent self-cleaning property via visible-light irradiation that was attributed to its outstanding catalytic performance. Highly sensitive SERS detection could be achieved with a LOD of 8.2 × 10⁻¹⁰ M for R6 G, and the substrate could be used repeatedly for at least four cycles with tolerable intensity attenuation. In addition, the 3D substrate exhibited long-term stability originating from the electron-donor effect of O-g-C₃N₄ and high reproducibility due to the uniform decoration of O-g-C₃N₄ on the Ag NRs through the strong interaction. Furthermore, using Ag NRs/O-g-C₃N₄, the recyclable detection of antibiotics in a water sample was demonstrated with high sensitivity, which indicates that the 3D Ag NRs/O-g-C₃N₄ substrate is a promising candidate for eliminating the challenges of single-use SERS substrates and building a portable SERS platform to sense organic molecular species.