Facile synthesis of fluorescence-SERS dual-probe nanocomposites for ultrasensitive detection of sulfur-containing gases in water and beer samples.

A highly structured fluorescent-SERS dual-probe nanocomposites were synthesized for the determination of sulfur-containing gases in water and beer samples. Initially, Au@Ag NPs were prepared by growing the Ag shell on the Au core in situ, modified with surfactant and fabricated with Zn2+. Then, MOF-5-NH2 assembled Au@Ag NPs were obtained through coordination between Zn sites and 2-aminoterephthalic acid. The principle was based on redox reaction between H2S and Au@Ag NPs, and the fluorescence turn-on effects were due to the charge transfer between SO2 and amino groups. The SERS intensity was related to the concentration of H2S (5 ∼ 60 nM), and an ultra-low detection limit of 2.26 nM was achieved. Importantly, the fluorescence performance was applied for SO2 analysis and exhibited good linear response. Moreover, the platform for H2S and SO2 in real samples revealed satisfactory results (95.6 ∼ 101.6% and 99.0 ∼ 104.4%). Therefore, the proposed system offered a precise detection of H2S/SO2 in food/environmental settings.