The pencil graphite electrode in the voltammetric analysis of biological important compounds

Voltammetric techniques represent reliable, inexpensive and rapid alternatives for the analysis of many biologically important compounds. On the other hand, redox reactions are found in many processes essential to life and voltammetric techniques allow the understanding of the mechanisms of some of them. The heart of any electrochemical analysis instrument is the working electrode, and current research is directed towards finding sensitive and selective sensors, but which are also cheap and, above all, non-toxic and environmentally friendly. One such electrode is the pencil lead graphite electrode (PGE), which is readily available commercially at low prices and also presents excellent electrochemical properties, being applicable both in the study of anodic and cathodic processes. This work presents few examples of voltammetric methods, based on PGE as such or electroactivated, developed for the analysis of some drugs and natural polyphenolic antioxidants in different matrices.