The presence of the precipitating ion in the electrolyte, in this case, chloride, favourably influences the voltammetry signals silver salts, AgNO3 and AgCl, previously immobilized on the electrode surface. Although it is possible to record the cyclic voltammogram of AgNO3(s) in the absence of chloride (S1), the presence of chloride, even in small quantities (S2) makes the current signals sharper in shape and size, allowing its use for purposes analytical. Using this analytical anion is also seen in the voltammetric response in chloride medium (Fig. S3); moreover, it is evident that the best definition of VC is achieved when silver ions are precipitated as AgCl previously.