MICROFABRICATED THIN-FILM MICROELECTRODE FOR AMPEROMETRIC DETERMINATION OF CO2 IN THE GAS-PHASE

A thin-film platinum microelectrode has been produced using microfabri cation techniques. This microelectrode behaves identically to the inla id microdisk electrode. The fabricated thin-film microelectrode device is used for amperometric determination of CO2 at room temperature. Th e microsensor shows a 90% response time of 30 s, a sensitivity of appr oximately 9 nA% CO2, and detection limits of approximate to 0.4% CO2 i n N-2. The calibration curve is linear over the entire CO2 concentrati on range, and the reproducibility of the sensor is good for 6 h of con tinuous operation. However, these performance characteristics are affe cted by electrochemical crosstalk between the electrodes under long-te rm operating conditions.