| 摘要 |
1,213,067. Electro-chemical analysis. E.I. DU PONT DE NEMOURS & CO. April 17, 1968 [April 18, 1967], No.18230/68. Heading G1N. [Also in Division C3] An electro-chemical cell for biomedical measurement of glucose comprises an oxygen-sensitive cell having the membrane coated with an enzyme gel (glucose oxidase) held in a polyacrylamide matrix. A commerically available oxygen-sensing cell with a micro-cathode (e. g. a cathode tip of 25 microns or less) similar to that illustrated in Fig. 1, (not shown) may be used. Dual cathode enzyme electrode In an alternative construction, Fig. 2, an nylon net 8 (about 35 microns thick) is impregnated with silicone plastic cement and fastened to a plastics cap 20 so that it covers the membrane 17. small holes 11, (50-300 microns dia. ) are made in the impregnated net directly over the cathode tip and filled with the enzyme in an acrylamide/N, N<SP>-</SP> methylene-bisacrylamide copolymer carrier. The enzyme in one hole is deactivated by heat-treatment whereby the co-operating cathode responds to oxygen only, and differential measurement with respect to the other cathode gives a true glucose reading. The platinum cathodes 12 are mounted in glass capillary tubes 13 just below the membrane and surrounded by an Ag-AgCl anode 14. Measuring circuit a null circuit with a servo-driven potentiometer providing a feedback signal is illustrated in Fig.3 (not shown). |
