Electrocatalytic oxidation of glucose on nanoporous gold membranes

Abstract

With characteristic of structural integrity and high surface area, nanoporous gold (NPG) prepared by dealloying method is proposed to be a highly sensitive catalyst for glucose electrooxidation. It can be found that a-NPG which obtained by electrochemical corrosion method has the highest sensitivity for glucose electrooxidation among the three studied samples. Under alkaline conditions, the catalytic current density of a-NPG is over 1.5 times and 17 times higher than that of f-NPG (prepared by free corrosion) and poly-Au electrode, respectively. Using a-NPG sample for glucose detection, the obtained minimum sensible concentration are 413 nM in alkaline media and 1 μM in neutral solutions. The a-NPG electrode also shows stable recovery and reproducibility characteristics. These results indicate that NPG may work as an efficient electrode material for electrochemical sensors and a promising catalyst for alkaline glucose fuel cells.

An overview of dealloyed nanoporous gold in bioelectrochemistry

“…In 0.1 M NaOH, planar gold displayed an onset potential of -0.6 V (vs. SCE) for glucose 5 oxidation, while -0.9 V (vs. SCE) for NPG with 12 nm pores [88]. …”

Nanoporous Gold Electrodes and Their Applications in Analytical Chemistry

“…The ability to use an electrode that has an electrochemically useful surface area that is 10-100 times larger than a traditional electrode thus offers much promise. Examples of small molecules that have been studied include dopamine [144], ascorbic acid [144], hydrogen peroxide [143,145], nitrite [146], cysteine [147], nitrophenol [148,149], hydrazine [150], and glucose [151].…”

“…At a traditional planar electrode, this analyte is difficult to be measured and thus, an enzyme (e.g., glucose oxidase) is often incorporated into the electrochemical sensor platform [152,153]. Recently, however, the nonenzymatic oxidation of glucose on nanoporous gold has been described in a number of reports [79,151,[154][155][156][157]. In 2008, Yin et al reported on the oxidation of glucose on nanoporous gold with different ligament sizes (6-250 nm) and also studied the effect of residual silver (6.8 to 37.9%) [154].…”

“…Compared to bulk gold or nearly pure nanoporous gold, higher catalytic activity for glucose oxidation in alkaline solutions was observed for nanoporous gold that contained Ag [155]. More recent work has focused on the electroactivity of nanoporous gold electrodes in phosphate buffer solutions and in the presence of chloride ions, ascorbic acid, and uric acid [79] as well as in different solution conditions [151]. Again, it was noted that glucose oxidation was dependent on pore size (50 nm-18 nm), with smaller pore size (18 nm) providing the highest sensitivity [79,151].…”

“…More recent work has focused on the electroactivity of nanoporous gold electrodes in phosphate buffer solutions and in the presence of chloride ions, ascorbic acid, and uric acid [79] as well as in different solution conditions [151]. Again, it was noted that glucose oxidation was dependent on pore size (50 nm-18 nm), with smaller pore size (18 nm) providing the highest sensitivity [79,151]. Again, this is consistent with the higher amount of Ag present in the sample with the smallest pore/ligament size.…”