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

Abstract

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).

Biosensing Membrane Base on Ferulic Acid and Glucose Oxidase for an Amperometric Glucose Biosensor

“…Figure 2 A shows the cyclic voltammogram from FA–GOx–BSA electropolymerization. After the first cycle, a decrease of the anodic peak current was observed; a similar performance was observed at other monomers such as aminophenol and phenylenediamine used for biosensors fabrication by electropolymerization [ 3 , 10 , 11 , 12 , 15 , 27 , 28 ].…”

“…At the second and successive cycles, the anodic current decreased rapidly, whereas the reduction currents persisted. The behavior is explained by the electrodeposition of a strongly passivating polymer layer onto the electrode surface; similar behavior was observed for phenols and aromatic amines electropolymerization [ 3 , 10 , 11 , 12 , 15 , 27 , 28 ]. Furthermore, at the three systems after the first cycle, a small oxidation at less positive potentials (Epa III ) appeared (figures inset).…”

“…The improvement of analytical parameters can be achieved by modifications of the biosensing membrane synthesis, utilizing modified recognized elements, redox mediators, or nanomaterials, as well as using different immobilization methods by employing a variety of chemicals that allow the synthesis of strong biosensing membranes [ 1 , 3 ]. Knowing that biosensor performance is strongly dependent upon the enzyme immobilization process [ 6 ], several research groups have explored enzyme immobilization by electropolymerization utilizing conductive and non-conductive polymers [ 3 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 ].…”