Development of a Miniature Sensor for Point-Of-Care Determination of Mercury

Mercury is toxic to human health. There are three different mercury species: metallic, inorganic and organic. They cause mostly neurological insults. In developing countries, subsistence gold mining entails mixing metallic mercury with crushed sediments to separate gold; highly volatile, mercury can be absorbed through inhalation. The US federal BEI is currently set at 50 ppb (μg/L) for urine. Metallic mercury is oxidized to mercuric mercury in the blood stream. This form is mainly excreted in urine and faeces. Urine analysis can detect mercury and levels can be correlated with toxic effects. The current gold standard analytical methods are AAS and ICP-MS, which are expensive, take some time, and not available in countries where testing is needed. Electrochemical techniques can reduce costs and time. Point-of-care sensors for detection of inorganic mercury concentration in urine could help providing rapid and effective treatment. This project will focus on developing and optimizing a point-of-care electrochemical system to detect mercury levels using gold sensors, then on its validation with human urine samples. The advantages will be the use of disposable sensors and portable instrument, rather than an expensive laboratory-based system.