SERS based monitoring of toluene vapors at ambient and elevated temperatures by using a ruffled silver nanolayer as a substrate.

Abstract

The authors describe a Surface enhanced Raman spectroscopy (SERS)-based method for the detection of gaseous toluene at different temperature regimes using 3D ruffled silver SERS substrates and a commercially available handheld Raman system equipped with a785nm laser. The 3D silver SERS substrates were synthesized via electroless deposition of silver on the ruffled sandpaper and HF-etched silicon wafers. The morphological characterization of the silver SERS substrates was carried out by atomic force microscopy and scanning electron microscopy. UV-Vis spectroscopy absorption spectra of the silver nanostructures showed plasmonicpeaks at 522nm and 731nm. Toluene vapors were collected with asyringe at ambient temperature and at 100°C, while SERS detection was always performed at room temperature. Toluene detection was based on the measurement of the Raman bands at 787cm-1 and 1003cm-1 (in thefingerprint region). The method allow gaseous toluene to be detected at its vapor concentrations of 522ppm (mg/L), 261ppm (mg/L) and 26ppm (mg/L). Graphical abstract Schematic presentation of an original method for the detection of toluene vapors by SERS technique. The collection of toluene vapors was carried out at room and at high temperatures. The vapors were transferred to methanol by bubbling. The SERS measurements were carried out at room temperature.