Sputtering enhanced peroxidase like activity of a dendritic nanochip for amperometric determination of hydrogen...

A nonenzymatic electrochemical nanoprobe is described for the fast determination of hydrogen peroxide (H₂O₂). A sputtered indium tin oxide electrode with a nano-hierarchical 3D gold structure is used. The nanoprobe was characterized by SEM, EDX, TEM, SAED, and electrochemical techniques. Figures of merit include (a) a fast response time (≤ 1.0 s), (b) two linear dynamic ranges that extend from 10^-12 M to 10^-10 M and from 10^-10 M to10^-5 M; and (c) a low limit of detection of 9.8 × 10^-13 M. The nanoprobe works in the clinical range and was applied for trace analysis of H₂O₂ in spiked blood samples, and recoveries ranged between 90 and 96%. It has negligible response (p < 0.001, for n = 3) toward glucose, citric acid, ascorbic acid, uric acid, glycine, and alanine. The shelf-lifetime is found to be 12 weeks. Graphical abstract Schematic representation of a dendritic nanochip with peroxidase-like activity. It is made from an indium tin oxide electrode with a nanohierarchical gold structure and was used for amperometric determination of hydrogen peroxide.