Mercury Chemical Sensors Based on Chalcogenide Glasses

Abstract

Mercury is one of the highly toxic heavy metal cations and its concentration is continuously increasing in the environment due to extensive industrial applications. Mercury species and Hg(II) ions have a serious impact on human health and may cause kidney intoxication, neurological damage, paralysis, chromosome breakage, and birth defects. Consequently, it is important to control mercury levels in natural and potable water. The highest concentration of mercury allowed in drinking water is 1 ppb. Chalcogenide glasses are promising membrane materials for chemical sensors. We will report R&D work on mercury sensors capable of continuous in situ monitoring of Hg(II) ions in natural and waste waters with a low detection limit of 2 ppb. Figure 1 shows typical sensor response in natural water at neutral pH 7.3 with mercury additions to determine low detection limit of the developed sensors. Sensor sensitivity, selectivity and stability will be discussed and applications to the analysis of natural and waste waters will be described. In addition, a special attention will be paid to sensor sensitivity mechanism since the sensor response is neither Nernstian nor linear. Figure 1