Two surfactant sensors, based on ion-pair 1:1 water-insoluble salts, have been prepared using Hyamine 1622 or tetradodecylammonium as cationic and dodecylbenzenesulfonate as anionic surfactant. Sensing materials have been incorporated in a PVC matrix containing o-nitrophenyl octyl ether as a solvent mediator and applied on a support of conductive resin without inner reference solution. The responses of these electrodes to sodium laurylsulfate and sodium dodecylbenzenesulfonate as well as the interferences of several common inorganic anions and anionic surfactants have been examined. The main parameters of evaluation of these electrodes and response times are presented and its behaviour is discussed. These membranes show good performance for use as a general potentiometric sensor responsive to anionic surfactants. © 1993.