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Inhibition-based biosensors for arsenic detection in water
Citation:
Li, T., E. Sahle-Demessie, S. Zeh, J. Hostert, C. Cash, S. Minderlean, AND J. Berberich. Inhibition-based biosensors for arsenic detection in water. American Chemical Society 2018 National Meeting, Boston,MA, August 19 - 23, 2018.
Impact/Purpose:
Population growth, and unsustainable agricultural and industrial activities have led to decrease in water quality and availability, causing ecological risks and challenging drinking water treatment plants to provide clean water. Many techniques are available for monitoring known water-contaminants, but they are typically expensive and cumbersome requiring trained scientists or technicians to use them correctly. Biosensors provide the opportunity for simple to use, disposable or continuous tests, for monitoring many of the common contaminants and emerging contaminants that water quality personnel are facing today.
Description:
Arsenic exposure from drinking water and food sources is of significant concern due to the high toxicity of arsenic. Arsenic can enter water and food supplies from natural deposits in rock and from commercial manufacturing and agricultural activities. Accurate measurement of arsenic in drinking water, food, and the environment at levels relevant to health requires expensive laboratory analysis. Low cost, portable test kits are available that can detect arsenic at higher levels, but they are typically unreliable at the low concentrations relevant to human health. Decentralized sensors that could be used to monitor drinking water sources, food from processing plants or wastewater from chemical processing sites would be powerful tools to help reduce exposure to arsenic and other ultratrace contaminants. Electrochemical biosensors, which use an enzyme, antibody or DNA as the detection element, are of interest for environmental monitoring due to their small size, simplicity and amenability to continuous monitoring applications. Inhibition-based biosensors show a change in electrochemical response due to the decrease in enzyme turnover in the presence of an enzyme inhibitor. The utility of inhibition-based biosensors has been demonstrated for the monitoring of pesticides and chemical warfare agents in water and in air. Arsenic is known to inhibit a number of enzymes including acid phosphatase, pyruvate dehydrogenase and acetylcholinesterase. We are developing inhibition based amperometric biosensors for arsenic using acetylcholinesterase and other arsenic sensitive enzymes. We will present the results from studies on enzyme inhibition and the impact on sensor response time and sensitivity. In addition, we will discuss immobilization on screen printed electrodes and the sensitivity of the biosensors to arsenic and potential interferents.