Patent ID: 6054039
Filing Date: 2000-04-25
Classification: G01N

Abstract:
An amperometric sensor for assaying the concentration of a fructosamine moiety contained in a biological fluid in the presence of interfering oxidizable substances also contained in the fluid, comprising:a sensing electrode, the sensing electrode comprising;a non-conductive support member strip,with the non-conductive support member strip coated with an electrically conductive layer, with the electrically conductive layer containing;a first redox mediator; anda reference electrode comprising;a non-conductive support member strip, with the support member strip coated with an electrically conductive formulation comprising Ag/AgCl dispersed in a resin formulation, and with the reference electrode having an opening; anda reagent strip, the reagent strip comprising;a water absorbent carrier, the water absorbent carrier impregnated with a mixture comprising;a second redox mediator that can be reduced by a fructosamine derivative,at least one surfactant,at least one stabilizer,a buffering agent to maintain a pH from about 8 to about 12; anda whole blood treatment component selected from the group consisting of;an erythrocyte filtration component and an erythrocyte lysing component;with the electrically conducting layer of the sensing electrode and the electrically conductive formulation of the reference electrode facing each other; and with the reagent strip superimposed on and in physical contact with the electrically conducting layer of the sensing electrode, and with the whole blood treatment component superimposed on and in physical contact with the reagent strip; and with the reference electrode superimposed on the whole blood treatment component so that the electrically conductive formulation coating the reference electrode is in physical contact with the whole blood treatment component; and with the whole blood treatment component completely covering the opening in the reference electrode; so that the sensing electrode and the reagent strip and the whole blood treatment component and the reference electrode form a sandwich.