Facile fabrication of ternary TiO₂-gold nanoparticle-graphene oxide nanocomposites for recyclable surface enhanced Raman scattering

A bi-functional ternary nanocomposite was developed by decorating TiO₂ and gold nanoparticles on the reduced graphene oxide nanosheets (TiO₂-Au-rGO) for recyclable surface enhanced Raman scattering (SERS) detection. TiO₂-Au-rGO nanocomposites have been shown to demonstrate the superior SERS performances, which can be used for highly sensitive detection of rhodamine 6 G with a limit of detection of 1.2 × 10⁻¹⁰ M. Subsequently, the surface can be cleaned automatically by the photocatalytic degradation of the adsorbed analytes into inorganic small molecules under visible light irradiation. This can be attributed to the excellent photocatalytic degradation ability, leading to a recyclable SERS application. After being used four times, their excellent SERS and catalytic performances can still be retained. These results suggest that the TiO₂-Au-rGO nanocomposites can provide a new strategy for fabricating recyclable SERS substrates, which are highly desirable for SERS practical application.