On-Chip Glucose Detection Based on Glucose Oxidase Encapsulated on a Platinum Modified Gold Microband Electrode

We report a two-step electrodeposition process incorporating glucose oxidase onto a platinum- modified gold microband electrode with an o-phenylenediamine and ß-cyclodextrin mixture. The bare microband electrodes were fabricated on silicon using standard microfabrication methods i.e. lithography and etching techniques. The two-step electrode modification process was characterized using cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. The enzymatic based microband biosensor exhibited a linear response to glucose from 2.5-15 mM using both linear sweep voltammetry and chronoamperometric measurements in buffer based solutions. The resulting miniaturized glucose sensor presented a number of advantages such as ease of use, fast response time, measuring within physiologically relevant glucose concentrations in addition to sensing in small sample volumes without the need for an external counter and reference electrode. The biosensor performance was tested in 30 µl volumes of undiluted fetal bovine serum. Whilst a reduction in signal was evident within 100 % serum samples, the sensor achieved linear glucose detection with increasing glucose concentrations (2-12 mM).