Surface-enhanced Raman scattering detection of dibenzothiophene and its derivatives without π acceptor compound using...

Dibenzothiophene (DBT) and its derivatives are important constituents of organosulfur compound in fossil fuels, which can result in one type of "acid rain" after burning process. Several technologies and methods have been developed to detect DBT, but they can be sophisticated and expensive. We have developed a two-step in-situ reduction method to fabricate Ag NPs modified glass fiber paper for SERS detection of DBT and its derivatives in a convenient and cheap way. Different from previous reports showing DBT cannot be detected by SERS, the substrate fabricated by our method revealed DBT's characteristic Raman peak at 1600 cm^-1. The dense and multilayer Ag NPs on glass fiber provided abundant spatial surface for DBT absorption and chemical interaction with Ag NPs, which led to CHEM enhancement in SERS detection. The mechanism was verified by UV-visible absorption spectrum and calculated Raman spectra. There was a good linear relationship between the SERS intensity at 1600 cm^-1 and the concentration of DBT solution between 1 × 10 ^-5 and 1 × 10^-3 mol/L and the limit of detection was 1 × 10^-6 mol/L. Spiked petrol sample was detected and the recovery rate of DBT is in the range of 94.53%-107.39%. This method provides a convenient and reliable way to detect DBT and its derivatives.