Development of a highly nanoporous platinum screen-printed electrode and its application in glucose sensing

摘要

The non-enzymatic detection of glucose has many advantages, but for practical applications the selectivity of these sensors must be improved. In this study a glucose sensor was fabricated by cyclic electrodeposition of a nanoporous platinum film onto screen-printed carbon electrodes from chloroplatinic acid/copper sulphate solutions. With successive electrodeposition cycles from 1.4 to -0.6 V vs. Ag/AgCl, the electrochemical surface area of the electrode increased with a maximum roughness factor of 3680 being obtained for an electrode subjected to 350 cycles. Scanning electron microscopy was used to characterise the surface morphology of the modified electrode. The electrocatalytic ability of the electrode towards glucose was investigated by amperometry in phosphate buffer (pH 7.4) at 0.4 V vs Ag/AgCl. The sensor exhibited excellent stability, a linear range up to 13 mM, and a fast response time of <5 s. Enlargement of the electrochemical surface area, resulted in excellent selectivity towards glucose, while signals for common interferents decreased. The sensor was successfully applied to the quantification of glucose in real blood plasma samples, where results achieved were in close agreement with those obtained using a commercial glucometer.