A sensor for the intermittent or continuous detection of the presence of at least one analyte in an environmental sample includes at least one enzyme that is selected to either (i) catalyze a reaction of the analyte to chemically convert the analyte to a product compound or (ii) be inhibited by the analyte...http://www.google.com/patents/US7422892?utm_source=gb-gplus-sharePatent US7422892 - Enzyme-based device for environmental monitoring
