Carbon nanomaterials have been very popular in the scientific community in recent years, because of their unusual physical and chemical properties. Their high electrocatalytic activity, very good electrical conductivity and mechanical resistance mean that scientists are constantly looking for new technological solutions to take advantage of the opportunities offered by nanomaterials in many areas of human activity. One of such area are potentiometric sensors. There are many publications in which scientists describe methods of construction, analytical parameters and practical applications of new sensors obtained using carbon nanomaterials, and often also describe methods of synthesis of new original nanomaterials. The purpose of this work was to characterize carbon-based nanomaterials and their application in the construction of ion-selective electrodes.