Rapid detection and mechanistic analysis of 3,4-Benzo(a)pyrene by surface-enhanced Raman scattering

In response to the difficulty of adsorbing 3,4-Benzo(a)pyrene (3,4-Bap) molecules onto the surface of precious metal substrates due to their hydrophobicity, a surface-enhanced Raman scattering (SERS) substrate (SD@AuNPs substrate) was constructed with the dual function of adsorption–detection. The substrate is a gold nanoparticle modified by sulfhydryl cyclodextrin, and the hollow cylindrical structure of cyclodextrin lends hydrophobicity to capture the molecule, which is utilized to achieve on-site selective analysis of 3,4-Bap pollutants using the signal changes in SERS spectra. The theoretical simulations and experimental results presented in this paper show that the maximum value of the electromagnetic enhancement property |E/E₀| of the substrate reaches 161. Under the synergistic ‘electromagnetic-chemical’ dual enhancement mechanism, the enhancement factor value of the substrate (EF_t = 4.87 × 10⁹) was comparable in order of magnitude to the experimental value (EF_e = 1.99 × 10⁸). The construction of the SD@AuNPs substrate and its mechanism study provide a theoretical and practical basis for SERS sensing of 3,4-Bap molecules in complex systems.