In-situ SERS detection of aromatic amine pollutants in fire-fighting wastewater using low-cost flexible substrates

Surface-enhanced Raman scattering (SERS) technology has been widely used in the field of environmental pollutant detection due to its fast and intuitive characteristics and low water interference. Herein, a low-cost and flexible SERS substrate was fabricated by transferring gold nanoparticles (NPs) onto polydimethylsiloxane (AuNPs@PDMS) membranes, which enabled highly sensitive detection of aromatic amine pollutants in wastewater after fire suppression. Finite time domain-difference calculations confirmed that the uniformly distributed NP gap significantly enhanced the localized electromagnetic field. The AuNPs@PDMS substrate performed satisfactorily in testing for rhodamine 6G (R6G) with a detection limit (LOD) of 5.5 × 10 −10  M. This substrate also demonstrated high reproducibility for detection of different concentrations of R6G and the relative standard deviation (RSD) was <7 %. These excellent SERS properties made AuNPs@PDMS a promising substrate in the detection of aniline and benzidine. Quantitative analysis of aniline and benzidine was achieved with LODs of 4.5 × 10 −9 and 7.8 × 10 −9  M, respectively. In addition, this substrate could be applied in rapid analysis of mixtures in wastewater after fire suppression using SERS without any complex pretreatments, displaying a great potential for rapid, high-sensitivity, and on-site detection of contaminants in fire-fighting sites.