An electrochemical gas sensor (10) includes a housing (11) which has a number of electrodes (31, 32), i.e. at least one working electrode (31) and at least one counter electrode (32), in addition to a liquid electrolyte (60). At least one of the electrodes (31, 32) and/or the housing (11) are at least partially formed of an absorption agent composition. A method of detecting acid gases employs the electrochemical gas sensor (10).