Dip-coating of a platinum electrode from an aqueous dispersion of polydimethylsiloxane provided an amperometric nitric oxide (NO) sensor with high performance characteristics such as rapid response (100% response time, 3 s), high sensitivity (detection limit, 20 nM; 1 M = 1 mol dm(-3)), high stability (usable for more than a month) and high selectivity (e.g., the ratio of response for uric acid to that for the same concentration of NO, less than 10(-4)).