Disposable Biamperometric Capillary-Fill Device for Glucose

A novel disposable biamperometric capillary-fill device for glucose was fabricated using thick-film technology and incorporating a polymer mediator and glucose oxidase. A simple electrode system consisting of two identical carbon screen-printed electrodes was used as a transducer. The reagent ink of glucose oxidase and [Os(bpy)₂(PVP)₁₀Cl]Cl was drop-coated on the biosensor substrate between the strips of the electrode. A microliter biamperometric capillary-fill device was constructed by adhesion of a glass cover and the biosensor substrate. A drop of test solution was automatically introduced into the microchannel by capillary action, and then a water-soluble layer containing glucose oxidase was solubilized and quickly dispersed throughout the volume of the microchannel. With a voltage of +200mV applied, the current response was directly proportional to the concentration of glucose in the solution. The disposable device for the analysis of glucose shows a linear response range from 0 to 15mM and is virtually insusceptible to interfering species such as 1mM ascorbic acid. The device designed was successfully applied to the determination of glucose in human serum.