*3.3. Differential Pulse Voltammogram (DPV)*

DPV is a technique that involves applying amplitude potential pulses on a linear ramp potential. In DPV, a base potential value is chosen at which there is no faradaic reaction and is then applied to the electrode. The base potential is increased between pulses with equal increments. The current is immediately measured before the pulse application and at the end of the pulse, and the difference between them is recorded (Figure 10). DPV is similar to the first derivative of a linear voltammogram in which the formation of a peak is observed for a given redox process. In the linear sweep technique, it has a shape similar to a wave, and the first derivative originates a peak.

**Figure 10.** Diagram of the application of pulses in differential pulse voltammetry (DPV).

As in polarography (dropping mercury electrode), the qualitative information of an analyte is given by its half-wave potential (E1/2), which corresponds to the potential at half the wave height. Similarly, in DPV, the peak potential, Ep, can be approximately identified through E1/2. Increasing the irreversibility, Ep deviates from E1/2 as the base of the peak widens and its height decreases. The DPV is therefore a graph of differences between measured currents and applied potentials as shown in Figure 9b [69,72].
