J. Heyrovský's Oscillographic Polarography. Roots of Present Chronopotentiometric Analysis of Biomacromolecules

Abstract

In 1941 J. Heyrovský invented Oscillographic Polarography (OP) with controlled alternating current (a.c.). The method was developed during the World War and the first commercially available instruments for OP were produced in Czechoslovakia at the beginning of the 1950’s. Such instruments offered derivative and cyclic OP curves allowing simple analysis of various compounds and stimulated the publication of hundreds of papers. Thanks to OP, electrochemical analysis of DNA started already in 1958. According to the present nomenclature, OP can be denominated as a.c. chronopotentiometry. Surprisingly, authors who later described derivative and cyclic chronopotentiometry did not consider J. Heyrovský’s OP methodology in their work. Present electrochemical studies of biomacromolecules take advantage of modern instruments for constant current chronopotentiometric stripping, allowing DNA and protein structure‐sensitive analysis. Recent progress in these studies is reviewed.

Structures of Peptidic H‐wires at Mercury Surface: Molecular Dynamics Study

“…The proposed MD approach can be applied in the interpretation of experimental data on the interfacial behavior of peptides at Hg‐surfaces. The main focus of attention has to be on the catalytic hydrogen evolution reaction (CHER) of peptides, where mercury electrodes play a unique role in the study of structural changes and biologically relevant interactions of the peptides containing proton‐donating amino acid residues . The first chronopotentiometric stripping observation of a CHER of peptides at a Hg‐electrode was performed 20 years ago by E. Paleček and co‐workers .…”

“…In 1998 E. Paleček and co‐workers found that CHER of peptides can be observed by chronopotentiometric stripping (CPS) producing a typical analytical output, the so‐called peak H . Peak H not only enables the highly sensitive label‐free and reagentless detection of biomolecules, but it is also highly sensitive to changes in their structures as well as to their intermolecular interactions .…”

“…In addition to the molecule-surface interaction itself, the surface charge is also very important for electrochemical studies. The electric field intensity can induce structural changes in adsorbed or specifically immobilized molecules, which was clearly shown as surface denaturation and electric field-induced denaturation in peptides [4,5], proteins [6][7][8] as well as in DNA [9,10]. The integrity of the adsorbed layer is strongly controlled by intermolecular interactions among its components and by the degree of internal structure, as is apparent, for example, in a self-assembled monolayer (SAM) or in layer-by-layer architectures [11].…”

Chronopotentiometry as a Sensitive Interfacial Characterisation Tool for Peptide Aptamer Monolayers

“…In light of this accumulated knowledge it is not surprising that the Cys‐p53 aptamer exhibits a good catalytic activity towards the hydrogen evolution at the mercury electrode. Indeed, around the physiological pH, the amino acid residues which are the most active for the catalytic hydrogen evolution reaction are Cys, Lys, and Arg , the aptamer containing the former two. In addition, the peptide must be present at the electrode at the potential (and at the moment) at which the catalysis takes place.…”

“…With his coworkers, he showed that at mercury (and amalgam) electrodes, all proteins exhibit a catalytic activity towards the hydrogen evolution reaction, giving rise in constant current chronopotentiometry to very intense peaks of great analytical significance owing to their high sensitivity to numerous parameters . This typical chronopotentiometric peak was coined as “Peak H” for H eyrovsky, H ydrogen evolution and H igh sensitivity , and various authoritative reviews on its analytical values are available . Herein, it is demonstrated that the peak H is not only useful for analytical purposes, but also for interfacial characterisations of relevant model systems.…”