Electrochemical carbon monoxide sensor with a Nafion (R) film

A solid-state planar electrochemical carbon monoxide sensor was built and s tudied. The sensor features a planar geometry of the electrodes (working, c ounter, reference), where all three electrodes are located on the same side of a substrate. The electrodes are covered by the CO-semipermeable proton- conducting polymer film. The sensor shows characteristics of a practical-us e level: response time, 30 s; range, 0-2000 ppm; sensitivity, 0.04 nA/ppm; life, more than 2 yr. The sensitivity is governed by both the CO permeabili ty of the polymer film and the CO oxidation rate, in other words, by the in termediate kinetic mechanism. (C) 1999 Elsevier Science B.V. All rights res erved.