Coulometric analysis method and a device therefor

A method for coulometric analysis for quantitative determination of a sample substance, comprising the steps of:

• providing a first electrode with a first substance having quinol formed from a reaction between the sample substance, which is a substrate of a quinone-dependent dehydrogenase, and quinone in the presence of quinone-dependent dehydrogenase, wherein the first substance is electroactive;
• providing a second electrode with a second substance, wherein the second substance is electroactive;
• providing an ion-permeable membrane between the first and second electrodes;
• measuring an electrical property generated by a potential difference from at least one self-driven reaction between the first and second substances;
• and
• determining the quantity of said sample substance from the measure of the electrical property.

An apparatus for coulometric analysis for quantitative determination of a sample substance, comprising:

• a first electrode with a first substance having quinol formed from a reaction between the sample substance, which is a substrate of a quinone-dependent dehydrogenase, and quinone in the presence of quinone-dependent dehydrogenase, wherein the first substance is electroactive;
• a second electrode with a second substance, wherein the second substance is electroactive;
• an ion-permeable membrane situated between the first and second electrodes;
• means for measuring an electrical property generated by a potential difference from at least one reaction between the first and second substances without application of an external power source;
• and
• means for determining the quantity of the sample substance from the measure of the electrical property.