
An electrode assembly for polarographic assay of glucose in solution having a laminated membrane, the outer membrane being from 1 to 20 .mu.m thick and having a pore size of 10 to 125 .ANG., the inner membrane having a thickness of 2 to 4 .mu.m, and bonded to the outer membrane with immobilized glucose oxidase. Rapid assays are carried out by measuring the current difference before equilibrium is attained and at least 5 seconds after initial contact of sample with the outer membrane.











