The invention relates to an electrochemical ethyl
alcohol sensor based on ethyl
alcohol oxidase and a preparing method thereof. The sensor is provided with three electrodes, the
working electrode is covered with an ethyl
alcohol oxidase film, ethyl alcohol in sample gas is selectively oxidized into
acetaldehyde by means of the ethyl
alcohol oxidase, and current generated through oxidization of
acetaldehyde on the
working electrode has a
linear relation with the concentration of ethyl alcohol. An
enzyme catalyst layer of the ethyl
alcohol oxidase film is not conductive and is an electrochemical inactive layer, and all reactions relevant to
enzyme have no direct relation with the current of the
working electrode of the electrochemical sensor. Catalytic reaction products of
enzyme are diffused into the working
electrode for further reaction, and then electrochemical current is generated and has a
linear relation with the concentration of ethyl alcohol. The working
electrode of the sensor is a low-activity material. The
response time of the ethyl alcohol sensor is short, test results are accurate, the ethyl alcohol sensor makes no obvious response to other organic gas but has extremely
high selectivity and sensitivity to ethyl alcohol, and the ethyl alcohol sensor can better meet the requirement for ethyl alcohol detection in complicated environments.