US Patent 8361308 Electrochemical carbon dioxide sensor

A method for the detection of carbon dioxide gas using an electrochemical sensor. The method includes exposing a gas to a sensor, which includes a non-conductive solid substrate and at least one each of a metal oxide sensing electrode, a reference electrode and a counter electrode positioned on the substrate. A solid polymer electrolyte anion-exchange membrane is in intimate contact with the sensing electrode, reference electrode and counter electrode. The method is highly sensitive and selective to carbon dioxide with a very rapid response time.