Cyclic voltammetry (CV) techniques were used to measure the concentration of nitric oxide (NO) and nitrogen dioxide (NO2) in air using an amperometric gas sensor. A porous gold membrane working electrode in sulfuric acid electrolyte was used with a counter electrode of bare Pt wire and quasi-reference electrode of electrodeposited Pt on a Pt wire. The anodic peak current (i(pa)) was proportional to the concentration of NO at various bias sweep rates. The limit of detection was about 4.8 ppm for NO in air or 31 ppm for NO2 in air for the CV methods. A parameter related to the diffusion coefficient and membrane permeability can be determined from CV measurements and was at the high range, 2.4 x 10(-4) cm(2) s(-1), of reported values of diffusion constants. Simple models of combined effects of gas and liquid mass-transport and electrokinetic current limiting mechanisms complicate explanation of observed currents with porous gas electrodes. (C) 2003 The Electrochemical Society.