A self contained glucose sensor is provided that generally comprises a strip type glucose sensing electrode having an active surface comprising an organic conducting redox salt dispersed in a polymeric membrane, with the membrane coating a conductive strip and a strip type Ag/AgCl reference electrode having its active surface separated from physical contact with the strip type glucose sensor and a carrier strip of water absorbent paper or film containing an enzyme system and an oxidizable dye. The water absorbent carrier strip is in simultaneous contact with both the active surface of the strip type glucose electrode and the active surface of the strip type reference electrode. When an aqueous solution containing glucose is brought in contact with the carrier strip containing the enzyme system an electrical potential, proportional to the concentration of glucose in the solution, is created which can be detected by an electrometer or other suitable device.