https://doi.org/10.1351/goldbook.E01940
In voltammetry and related techniques, a substance that undergoes a change of @O04365@, or the breaking or formation of chemical bonds, in a @C01007@. If an electroactive substance B is formed, in the solution or electrode, by a @C01033@ from another substance C, the substance C should be called the precursor of B. In potentiometry with @I03244@, a material containing, or in ion-exchange equilibrium with, the sensed ion. The electroactive substance is often incorporated in an @I03026@ matrix such as poly(vinyl chloride) or silicone rubber.