Electrochemical Detection of Heavy Metal Ions Using Amino Acids and Oligopeptides as Complexing Ligands

Abstract

Using biological components to provide selectivity for monitoring heavy metal ions in sensory devices are attractive due to the natural occurrence of metal-binding peptides and proteins. They have advantages over conventional analytical techniques such as atomic absorption spectroscopy, inductively coupled plasma mass spectrometry and anodic stripping voltammetry, because they have the potential to give an estimate of the bioavailability of heavy metals as opposed to measuring total metal concentrations. The metal-binding properties of peptides have been studied extensively [ 1 ] but research into using amino acids and peptides as biosensors for the detection of heavy metal ions is relatively new. Apart from the selectivity imparted from using different peptide ligands, an additional level of selectivity can be achieved by exploiting the different redox potentials of different metals. As a consequence, the following work describes the use of peptide-modified electrodes as highly selective and sensitive metal ion biosensors. [ 2 ]