Adsorptive stripping voltammetry of biomacromolecules with transfer of the adsorbed layer

Abstract

A new analytical method, based on the adsorptive preconcentration of biomacromolecules on an electrode, the transfer of the adsorbed layer into a new medium (containing background electrolyte) and subsequent voltammetric analysis, is proposed. This method is called adsorptive transfer stripping (inverse) voltammetry, AdTSV (AdTIV). The adsorption of nucleic acids, some proteins, polysaccharides, and lipids on a mercury electrode can be carried out on open circuit from drops of solution; owing to this fact, it is possible to reduce the volume of the sample usually used in voltammetric analysis by a factor of fifty or more. In addition, AdTSV makes it possible (a) to carry out the voltammetric analysis of biomacromolecules adsorbed from media not suitable for voltammetric analysis of the conventional type, (b) to exploit the differences in adsorbability of substances to separate them on the electrode, (c) to study the interaction of biomacromolecules immobilised on the surface of the electrode with substances contained in the solution without the results of the voltammetric measurement being affected by the interactions in the bulk of the solution, and (d) to study the effect of electrode potential on the properties and interactions of the adsorbed macromolecules.