Renaissances and current trends with electrochemical sensors and biosensors

were developed (e.g., differential pulse voltammetry) on one hand in combination with stripping analysis on the other. During that period an immense number of publications appeared dealing mainly with the determination of the four “classical” metals easily accessible by inverse voltammetry on mercury electrodes, i.e., Zn, Cd, Pb and Cu. Along with such prosperity in voltammetry also potentiometry slipped into its golden age with the development of new ion selective membranes for many of the elements of the periodic system. In the nineteen eighties a second renaissance could be noticed due to the chemical modification of amperometric electrodes. Whereas the use of mercury electrodes decreased new electrode materials moved into the focus of interest, such as vitreous carbon (glassy carbon), noble metals, heterogeneous composites (carbon paste,4 screen-printed electrodes) in combination with altered surfaces which facilitated broader applicability of electroanalytical methods. Earlier landmarks of sensor design, such as the first amperometric sensor (oxygen electrode5) and the first biosensor (glucose sensor6), both developed by Leland Clark, contributed to a peak-like increase of electroanalytical studies.