| 摘要 |
<p>An apparatus is provided for measuring the concentration of a substance in a sample solution. The apparatus comprises first electrode means (20, 22, 24), second electrode means (30, 32, 34) and an enzyme channel (14) between the first and second electrode means. The enzyme channel (14) contains an enzyme for catalysing a reaction of the substance whose concentration is to be measured. In use, a known volume of the sample solution is presented to the first electrode means (20, 22, 24) in a test solution (12) including an excess of a mediator, one of reduction or oxidation of the mediator being coupled to the reaction of the substance. The first electrode means (20, 22, 24) is arranged to ensure that the mediator is respectively completely oxidised or reduced, and also to remove any interferent species. The test solution (12) is then passed through the enzyme channel (14) so as to permit reaction of all of the substance present in the solution, whereby a quantity of the mediator is respectively reduced or oxidised. The test solution (12) is then presented to the second electrode means (30, 32, 34) which are arranged to respectively oxidise or reduce the quantity of mediator which had been respectively reduced or oxidised. This produces a quantity of charge through the second electrode means (30, 32, 34) which is measured by means (26-28; 36-38; 40-44) for measuring said quantity of charge.</p> |
