Surface-modified electrode and its use in a bioelectrochemical process

Abstract

In a bioelectrochemical process in which the electrons are transferred directly, without use of a mediator, such as a redox dye or cofactor, between an electrode and an electroactive biological material, such as an enzyme or a protein, in either direction, rapid electron transfer has previously been achieved between an electrode and the positively charged protein horse-heart cytochrome c by adding a surface-modifier such as 4,4'-bipyridyl or a derivative thereof. It has now been found possible to promote electron transfer to either a positively or a negatively charged protein using the same surface-modifier for either job, namely a compound of formula ##STR1## wherein: the pyridine ring shown is substituted in the 2-, 3- or 4-position by the (methylene)hydrazinecarbothioamide group shown; R.sup.1 represents hydrogen atom(s) or one or two methyl or ethyl groups in the 2-,3- or 4-position (when the said position is not substituted by the (methylene)hydrazinecarbothioamide group shown); R.sup.2 represents a hydrogen atom or a methyl group; R.sup.3 represents a hydrogen atom or a methyl group; and R.sup.4 represents a hydrogen atom or a methyl group.

Dependencies are inferred from the claim text.