Mesoporous M-TiO₂ NCs, functionalized by PATP, can capture toxic anilines and phenols by azo coupling. Loading these nanodevices with Ag NPs offers the possibility for a sensitive quantitative determination of target compounds by SERRS spectroscopy, which allows multiplex detection because of the specific vibrational fingerprints. Sensitivity and selectivity can be further enhanced by concentrating the hybrid particles by an external magnet and compound-specific binding (anilines versus phenols). The bound toxic compounds can be degraded by TiO₂-assisted photocatalysis after removal of the loaded hybrid particles from the sample solution with an external magnet. The degradation process can be enhanced in the presence of plasmonic Ag nanostructures. Magnetic TiO₂ nanocomposites (M-TiO₂ NCs) are fabricated and functionalized for determination and elimination of toxic anilines and phenols. The compounds, bound to M-TiO₂ NCs by azo coupling, may be degraded by TiO₂-assisted photocatalysis, making the NCs recyclable. Addition of Ag nanoparticles allows the detection and identification of the azo products by surface-enhanced resonance Raman spectroscopy and accelerates photocatalytic detoxification.