Electrodeposited highly porous gold microelectrodes for the direct electrocatalytic oxidation of aqueous glucose

Abstract High-surface area electrode materials are particularly relevant for a vast range of applications, especially in the field of catalysis and electrochemical energy conversion (e.g. fuel cells). In this work high surface area gold electrodes were produced by direct electrodeposition of highly porous gold (hPG) films onto gold electrodes via a very fast (15 s), simple, and cost-effective methodology that involves a hydrogen bubble template. This methodology was also successfully applied to gold microelectrodes produced by lift-off lithography, thus paving the way for interesting lab-on-a-chip applications. The hPG electrodes showed very high sensitivity towards glucose, with a detection limit of 5 μM. This reactivity was maintained when the electrodes were tested in artificial urine, thus encouraging their use in healthcare. The hPG electrodes showed high sensitivity also towards other aldoses and other reducing sugars (maltose, lactose, galactose).