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 in the presence of a substrate compound. The sensor also includes at least one sensor for monitoring or at least one indicator compound selected to produce a measurable change of state as a result of the interaction of the analyte and the enzyme. Optionally, each of the enzyme and the indicator compound are incorporated within a single polymer.