Niğde Ömer Halisdemir University Journal of Engineering Sciences, cilt.10, sa.1, ss.79-83, 2021 (Hakemli Dergi)
In this study, two different surface modification methods have been tested for easy detection of chloroform, which is harmful to human health in case of excess in the mains water, with a Quartz Crystal Microbalance (QCM) sensor. In the first coating method, acidic and basic solutions of 3-mercaptopropyltrimethoxysilane (MPS) in ethyl alcohol were applied respectively. In the second coating method; Acidic MPS was applied in the first step and then surface modification was completed using 2-mercaptoethanol (ME). In Coating-1, average frequency shifts of -180(±30) Hz, -200(±40) Hz and +40(±10) Hz were recorded for acidic MPS, basic MPS and 10 ng mL chloroform, respectively. In Coating-2, chloroform molecules formed covalent bonds with thiol groups and the mean frequency shifts obtained for acidic MPS, ME and 10 ng / mL chloroform were -180(±30) Hz, -80(±15) Hz, and -70(± 8) Hz, respectively. According to empirical results, coating-2 method provided a better surface modification than coating-1 method. Resonance frequency shifts of -2.5(±1), -12(±4), -70(±8) and -356(±87) Hz respectively were obtained at chloroform concentrations of 0.1, 1, 10, and 100 ng/mL by using QCM sensor modified with MPS + ME.