Flexible Non-Enzymatic\nGlucose Sensors: One-Step Green\nSynthesis of NiO Nanoporous Films via an Electro-Exploding Wire Technique

In this study, we successfully synthesized nickel oxide\n(NiO) nanoparticles\n(NPs), i.e., samples <b>NiO 24V</b>, <b>NiO 36V</b>, and <b>NiO 48V</b>, via an environmentally friendly one-step electro-exploding\nwire technique by employing three distinct voltage levels of 24, 36,\nand 48 V, respectively. Sample <b>NiO 48V</b> showed the most\nrugged surface and smallest particle size, which helped to enhance\nelectrocatalytic properties. The highest Ni<sup>3+</sup> content of\nsample <b>NiO 48V</b> contributed to the increasing redox current\nand rendering highly enhanced chemical reactions and thereby improving\ntheir electrochemical properties and electrocatalytic performance\nin the glucose oxidation processes in alkaline (0.1 M NaOH, pH = 13)\nmedia. The <b>NiO 48V</b> electrode showcased an excellent linear\ndetection range spanning from 0.1 to 1 mM, featuring a remarkable\nsensitivity of 1202 μA mM<sup>–1</sup> cm<sup>–2</sup> and an exceptionally low limit of detection (LOD) value of 0.25\nμM. Remarkably, NiO NPs exhibited exceptional long-term stability,\ncommendable reproducibility, favorable repeatability, and outstanding\nselectivity. This study also highlights the excellent operational\nperformance of the <b>NiO 48V</b> electrode in real-world samples,\nsuch as commercially available beverages and human urine, highlighting\nthe practical nature of these nonenzymatic sensors in real-life scenarios\nfor the food industries, clinical diagnostics, and biotechnology applications.