Bubble electrodeposition of gold porous nanocorals for the enzymatic and non-enzymatic detection of glucose

Au nanocorals are grown on gold screen-printed electrodes (SPEs) by using a novel and simple one-step electro-deposition process. Scanning electron microscopy was used for the morphological characterization. The devices were assembled on a three-electrode SPE system, which is flexible and mass producible. The electroactive surface area, determined by cyclic voltammetry in sulphuric acid, was found to be 0.07 +/- 0.01 cm(2) and 35.3 +/- 2.7 cm(2) for bare Au and nanocoral Au, respectively. The nanocoral modified SPEs were used to develop an enzymatic glucose biosensor based on H2O2 detection. Au nanocoral electrodes showed a higher sensitivity of 48.3 +/- 0.9 mu A/(mM cm(2)) at + 0.45 V vs Ag vertical bar AgCl compared to a value of 24.6 +/- 13 mu A/(mM cm(2)) at + 0.70 V vs Ag vertical bar AgCl obtained with bare Au electrodes. However, the modified electrodes have indeed proven to be extremely powerful for the direct detection of glucose with a non-enzymatic approach. The results confirmed a clear peak observed by using nanocoral Au electrode even in the presence of chloride ions at physiological concentration. Amperometric study carried out at + 0.15 V vs Ag vertical bar AgCl in the presence of 0.12 M NaCl showed a linear range for glucose between 0.1 and 13 mM. (C) 2016 Published by Elsevier B.V.