Electrochemical system for determining the coagulation time of blood

摘要

The process for immobilizing a reagent (30) on an electrode (24a) for determining a blood clotting time by amperometry, comprises supplying a thick liquid composition comprising the reagent and a N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) type buffer medium on the electrode, and drying the composition for immobilizing the dry reagent on the electrode by lyophilization. The reagent comprises a substrate whose terminal link is optionally cut by thrombin enzyme for releasing charged groups (LG) and an initiating factor for clotting. The process for immobilizing a reagent (30) on an electrode (24a) for determining a blood clotting time by amperometry, comprises supplying a thick liquid composition comprising the reagent and a N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid (HEPES) type buffer medium on the electrode, and drying the composition for immobilizing the dry reagent on the electrode by lyophilization. The reagent comprises a substrate whose terminal link is optionally cut by thrombin enzyme for releasing charged groups (LG) and an initiating factor for clotting. The dry reagent is immobilized on the electrode at the end of its chain opposite to the chain comprising the charged group. The initiating factor of the clotting comprises thromboplastin. The substrate comprises an oligopeptide derivative having a stereospecific configuration of a thrombin enzyme site to allow cutting at the charged end of the substrate. An independent claim is included for an electrochemical sensor for determining a clotting time of entire blood.