Plasmon-assisted self-cleaning sensor for the detection of organosulfur compounds in fuels

Monitoring of organosulfur compounds in fuels is an urgent need for the control of their quality. The major deficiencies of common approaches for the determination of sulfur-containing heterocycles, especially dibenzothiophene (DBT) derivatives, are the time and equipment demand, as well as the impossibility of portable measurements. Thus, the reliable and sensitive detection of organosulfur derivatives in fuels, in an expeditious and portative manner, represent an actual challenge. In this work, the advanced design of SERS substrates for the reliable and ultrasensitive detection of DBT derivatives in real samples of biodiesel is proposed. The SERS substrates were created based on the plasmon-polariton supported gold grating, providing effective and reproducible SERS measurements. An additional coating of the gold grating surface with a thin Pt layer facilitates the entrapping of sulfur-containing organic compounds. The created SERS substrates show a low detection limit (10^-12 M), high reliability and compatibility with portable Raman spectrometers. Moreover, the possibility to regenerate the SERS substrate via a plasmon-induced reaction in cyclohexene was also demonstrated, providing bright opportunities for sensor re-utilization.