Improvements to ATR-FTIR based chemical sensors for the detection of organic contaminants dissolved in water

Attenuated total reflectance Fourier transform infrared (ATR-FTIR) based chemical sensors have been widely used for the detection of a variety of hydrocarbon compounds. The selection of an appropriate chemoselective membrane material to coat the zinc selenide (ZnSe) internal reflectance element is a crucial step in achieving acceptable sensor performance. Although there are many materials available, membrane degradation and biofouling is still an issue that has limited long-term sensor deployment in environmental waters. It is proposed that superhydrophobic membranes can suppress the diffusion of water and biomolecules to the sensing surface making the sensor less susceptible to fouling problems. This paper explores whether single-walled carbon nanotube/polymer dispersions can be used to improve sensor performance for BTEX (benzene, toluene, ethylbenzene, xylenes) compounds dissolved in water.