Detection of aromatics in the gas phase by surface-enhanced Raman scattering on substrates chemically modified with p-tert-butylcalix[4]arenetetrathiol

In this paper the possibilities are demonstrated to detect gaseous aromatic compounds by surface-enhanced Raman scattering (SERS) on substrates chemically modified with p-tert-butylcalix[4]arenetetrathiol (BCAT). Benzene, toluene, ethylbenzene, and isomers of xylene are reversibly deposited through interaction with the surface-bound BCAT molecules. Due to this interaction, the detection limits for the investigated aromatics are decreased in comparison to mere adsorption at bare metal surfaces. The limits of detection were found to be between 1.2 and 3.1 mg/L for all substances. The dynamic range for the detection of gas phase concentrations is up to two orders of magnitude with a roughly linear relationship between SERS band intensities and concentrations. The response time of the SERS sensor is about one minute.