Selection of Applied Potential

The EC properties of an analyte can be studied by measuring its response at different potentials, where the potential is changed incrementally between injections. It is best to start at a high potential and decrease it, since the background current stabilizes more quickly when lowering the potential. 

Electrode material Measuring technique Typical analytes Detection limits 

The resulting curve, where the peak height (or area) is presented as a function of potential, is called a hydrodynamic voltammogram (Fig. 4). This can be considered as an EC spectrum of the analyte. The half-wave potential is characteristic of the analyte under these conditions, and is independent of concentration. The EC properties can also be studied by scanning the potential (voltammetry). However, in the final optimization a hydrodynamic voltammogram created by detection at a constant potential is usually required. 

---

These methods are also selective because of control of the electrochemical spectrum through selection of applied potential range. In addition, selectivity can be improved by modification of the electrode surface with membranes, electrocatalysts, etc. 

Developers of thick-film sensors have removed the interference from the sample by chemical oxidation [12,13], by-passed it by selection of applied potentials and electrode materials, including the use of redox mediators [14,15], and kept it from electrode surfaces by inner and outer membranes [16-19]. 

---