Among electrochemical detection methods, square-wave anodic voltammetry (SW-ASV) is the most popular. However, this method has a number of limitations, for instance, mercury or bismuth electrodes are usually used as a working electrode, which are highly toxic substances. This article is devoted to the study of the use of track-etched membranes based on polyethylene terephthalate as a basis for electrochemical sensors. The modification of the surface of membranes was carried out by the method of photoinitiated graft polymerization of methacrylic acid. Magnetron sputtering with a mask was used to obtain electrodes on both sides of the membrane. The sensor has been tested for sensing toxic cadmium ions in a concentration range of 0.5 to 12.5 mg/L.