Transfer of an analyte from a test solution to an
electrode surface as the first step in
stripping voltammetry.
Note: Analyte accumulation can be achieved by the following methods:
- electrodeposition of metal atoms onto a solid electrode,
- reduction of metal ions on a mercury electrode and dissolution of the formed metal atoms in the mercury (amalgam formation),
- precipitation of sparingly soluble mercuric, mercurous, or silver salts on mercury or silver electrodes,
- precipitation of metal oxides, hydroxides, or other insoluble salts on an inert (usually noble metal or carbon) electrode,
- chemical reaction of an analyte with an electrode material,
- adsorption of electroactive organic substances,
- adsorption of complexes of metal ions with organic ligands,
- synergistic adsorption of complexes,
- anion-induced adsorption of metal ions,
- surface complexation of metal ions,
- ion-exchange reactions at surface-modified electrodes,
- extraction by ion transfer across the interface of two immiscible electrolyte solutions,(m) reaction by biological recognition processes involving nucleic acids, antibodies, enzymes, etc.
Example: \(\pu{50 to 150 nm}\) magnetic particles of gold-coated \(\ce{Fe3O4}\), modified with the tripeptide \(\ce{Gly-Gly-His}\) to capture \(\ce{Cu^{2+}}\). Particles are then returned to an electrode surface by a magnetic field.
Source:
PAC, 2020, 92, 641. 'Terminology of Electrochemical Methods of Analysis (IUPAC Recommendations 2019)' on page 680 (https://doi.org/10.1515/pac-2018-0109)