A continuous, noninvasive glucose monitoring method is necessary for diabetic patients to reduce the risk of hypoglycemia. This paper was to develop a bifunctional biosensor for the simultaneous extracting and detecting the subcutaneous glucose by reverse iontophoresis. The biosensor was constructed by a tri-electrode planar configuration and multi-layer sensitive membrane composed of mediator, enzyme and cross linking agents. A hydrogel membrane was deposited on the top of the device to act as a collected reservoir of the extracted glucose. The electrochemical characteristic of the amperometric biosensor was evaluated using cyclic voltammetry at applied potentials from -0.2 V to 0.6 V vs. Ag|AgCl electrode. The glucose biosensor showed a high sensitivity of 14.24 nA µM-1 cm-2 at a low applied potential (-0.1 V vs. Ag|AgCl). Finally, the biosensor was used for noninvasive glucose monitoring by reverse iontophoresis using the naked mouse skin as the model. An excellent linear relationship (r2=0.99) was found between the subcutaneous glucose concentration (0-18 mM) and the biosensor current response. The results suggest that the biosensor was suitable for subcutaneous glucose monitoring by reverse iontophoresis.
Liu, J., L. Jiang, H. Liu, X. Cai
Journal of Electroanalytical Chemistry