Preparation and characterization of Prussian blue nanowire array and bioapplication for glucose biosensing

Prussian blue nanowire array (PBNWA) was prepared via electrochemical deposition with polycarbonate membrane template for effective modification of glassy carbon electrode. The PBNWA electrode thus obtained was demonstrated to have high-catalytic activity for the electrochemical reduction of hydrogen peroxide in neutral media. This enabled the PBNWA electrode to show rapid response to H2O2 at a low potential of -0.1 V over a wide range of concentrations from 1x10(-7) M to 5x10(-2) M with a high sensitivity of 183 microA mM(-1) cm(-2). Such a low-working potential also substantially improved the selectivity of the PBNWA electrode against most electroactive species such as ascorbic acid and uric acid in physiological media. A detection limit of 5x10(-8) M was obtained using the PBNWA electrode for H2O2, which compared favorably with most electroanalysis procedures for H2O2. A biosensor toward glucose was then constructed with the PBNWA electrode as the basic electrode by crosslinking glucose oxidase (GOx). The glucose biosensor allowed rapid, selective and sensitive determination of glucose at -0.1 V. The amperometric response exhibited a linear correlation to glucose concentration through an expanded range from 2x10(-6) M to 1x10(-2) M, and the response time and detection limit were determined to be 3 s and 1 microM, respectively.