Pulsed electrochemical detection in bioanalysis: chemical fingerprinting

Abstract

Pulsed Electrochemical Detection (PED) is a revolutionary approach to the simple, sensitive, and direct detection of numerous polar aliphatic compounds, especially carbohydrates. This technique exploits the electrocatalytic activity of noble metal electrode surfaces to oxidize various polar functional groups. In PED, multi-step potential-time waveforms at Au and Pt electrodes realize amperometric/coulometric detection while maintaining uniform and reproducible electrode activity. The response mechanisms in PED are dominated by the surface properties of the electrode, and, as a consequence, members of each chemical class of compounds produce virtually identical voltammetric responses. Thus, the full potential is realized when combined with high performance liquid chromatography (HPLC). This paper reviews the fundamental aspects of PED and details a novel approach to the chemical "fingerprinting" of natural products. Applications include the characterization of tobacco, peptones, and bacteria.