75 years of J. Heyrovsky's Oscillographic Polarography and Present Constant Current Chronopotentiometry

On 25th April 1941, at a meeting of the Czech Chemical Society in Prague, Jaroslav Heyrovsky delivered his lecture "Use of oscillograph in polarography". This lecture was published in Chemicke Listy in December 1941. His lecture marked the beginning of the oscillographic polarography with controlled alternating current (OP). In the first half of the 1950's, a simple instrument Polaroskop P 524 became available, stimulating wide application of OP as a method of fast and simple chemical analysis of various compounds, including biomolecules. In the 1960's and in the following decades a number of papers on chronopotentiometry were published but J. Heyrovsky's OP was almost forgotten. At present we can witness another step in the development of chronopotentiometry in the application of CPS in the analysis of biomacromolecules and particularly in the structure-sensitive analysis of proteins based on catalytic hydrogen evolution reaction (CHER). This analysis requires mercury-containing electrodes, such as HMDE (hanging mercury drop electrode) or solid amalgam electrodes, because the CHER has not been observed with any other electrode. We believe that Professor J. Heyrovsky would be satisfied by the fruitful development of chronopotentiometry and its application in bioelectrochemistry, stimulated by his OP.