Carbon Electrodes in Electrochemical Analysis of Biomolecules and Bioactive Substances: Roles of Surface Structures and Chemical Groups
Abstrakt
In this chapter we focus on the properties of graphitic carbon and boron-doped diamond (BDD) electrodes from the point of view of surface micro- and nanostructures, chemistry of surface termination, effects of these characteristics on electron transfer and adsorption characteristics of the electrodes. Their properties are discussed in relation to electrochemical responses measured for typical groups of analytes, such as nucleic acid and protein constituents or other electroactive compounds.
In general, basal planes of graphitic materials are sites of preferential adsorption of organic compounds while the edge planes and defects are sites of fast electron transfer for a number of analytes. At the BDD, fast electron transfer kinetics is observed particularly at hydrogenated and polished surfaces.
Surface termination with oxygenous groups causes the electron transfer rate to decrease and renders the carbon surface hydrophilic properties, manifested in decreased adsorption of hydrophobic molecules and involvement of coulombic forces and hydrogen bonds in interactions of relevant analytes with the electrode surfaces. Examples of applications in the area of electroanalysis of biomolecules and their components are briefly discussed.