Controlled Synthesis of Porous Co₃O₄ Nanostructures for Efficient Electrochemical Sensing of Glucose

Abstract

A shape-controlled strategy was developed to synthesize porous Co3O4 nanoparticles, and the delicate morphology including nanourchins, nanowires, nanoflowers, and nanoplates could be well adjusted by adopting different anion precursors. The Co3O4 nanomaterials were further applied as the electrocatalysts for glucose detection, and the effect of nanostructure on the electrochemical performance was investigated. Results show that Co3O4 nanourchins illustrate the highest glucose sensitivity of 565 mA mM-1 cm-2 and a good linear detection ranging from 20 μM to 0.25 mM. The improved performance of obtained products was originally from the large surface area and high pore volume, which leads to a significantly increased accessibility of reactant and decreased Faradic electron transfer resistance, making it a promising candidate for glucose sensing.

Synthesis of Titanium Oxide Nanoparticles Using Root Extract of Kniphofia foliosa as a Template, Characterization, and Its Application on Drug Resistance Bacteria

“…Several methods have been employed in the synthesis of TiO 2 NPs and other metal and metal oxide NPs which include chemical and physical means with the former being the one mostly practiced industrially. These methods however have their own demerits as they require high temperatures, are potentially hazardous, are not safe to the natural environment, incorporate toxic chemicals as a reducing and capping agent during synthesis process, and at same time, are expensive [10,11].…”

Electrochemical sensors based on metal nanoparticles with biocatalytic activity

“…For instance, cobalt oxide has been extensively studied for glucose detection, performed at pH 13–14 in either NaOH or KOH solution [ 19 – 21 ]. Cyclic voltammetry (CV) analysis of a cobalt oxide-modified electrode shows two pairs of redox peaks attributed to the conversion of Co 3 O 4 to CoOOH, followed by its oxidation to CoO 2 , and the reverse reactions [ 20 ]. Glucose oxidation is a two-electron process in which gluconolactone is produced.…”

“…Luo et al focused their research on demonstrating that the catalytic activity of different Co 3 O 4 nanostructures depends on their shape [ 20 ]. To do so, they performed a shape-controlled Co 3 O 4 nanostructure synthesis resulting in nanourchins, nanowires, nanoflowers, and nanoplates.…”

“…Figure adapted from ref. [ 20 ]; copyright © 2019 Jiankang Luo et al Used under CC BY license 4.0 ( http://creativecommons.org/licenses/by/4.0/ ) …”

Au-Seeded Ag-Nanorod Networks for Electrocatalytic Sensing

“…Application of enzymes as a catalytic biosensor has been long known in the literature, but due to their possible denaturation and digestion in abnormal conditions (higher temperature, variable pH, nonaqueous environment, etc. ), high costs in preparation and purification, the requirement of expertise in handling enzyme-based assays, and lack of large-scale production, the fabrication of an enzymatic catalytic sensing platform for daily use in the industrial scale has not become feasible to date. , In comparison to catalytic enzyme biosensors, nonenzymatic nanomaterial-based catalytic sensors also have the same essential components as an effective catalyst, i.e., a chemical receptor or a more universal porous moiety to hold the analyte selectively or nonselectively and a transducer with a lower faradic electron transfer resistance to generate a high-throughput electrical signal for ultrasensitive sensing. As mentioned, to avoid the drawbacks of enzymatic catalysts, new-generation nonenzymatic universal nanoscale catalytic sensing platforms with enhanced catalytic activity governed by the inherent crystal defects and grain boundaries within the nanomaterials, catalytic hotspots at the cross-junctions, durability due to efficient surface passivation, excellent stability over a pH and solvent range, , and low cost of fabrication are in demand for high-throughput physiological diagnosis.…”