Electrochemical Detection of H₂O₂ on Graphene Nanoribbons/Cobalt Oxide Nanorods‐Modified Electrode

Abstract

The most important biological changes which have to be monitored is the mechanism of ageing in the human body where the mitochondria play a major role. Hydrogen peroxide (H2O2) is one of the important markers for the reactive oxygen species (ROS), which denatures the protein and DNA, that was the main contributory factor of ageing. So, it is very important to monitor H2O2 levels in the biological samples. Herein, we reported the preparation of 1D graphene nanoribbon/cobalt oxide nanorod (GNR/Co3O4) based nanocomposite-modified electrochemical sensor for H2O2. Firstly, GNR was synthesized by oxidative unzipping of multiwalled carbon nanotubes (MWCNTs). Secondly, cobalt oxide nanorods (Co3O4) were grown onto GNR by a chemical reduction process. As-prepared nanocomposite was characterized by UV-Visible spectroscopy (UV-Vis) and HR-TEM. Electrochemical properties of GNR/Co3O4-coated electrode were studied by cyclic voltammetry (CV) which showed two redox peaks at 0.93 and 0.88 V in phosphate buffer solution. Next, the electrocatalytic activity of GNR/Co3O4-coated electrode was studied against H2O2 oxidation. The electrochemical studies revealed that GNR/Co3O4-coated electrode exhibited high electrocatalytic activity for H2O2 oxidation at 0.925 V. This sensor showed a linear response for H2O2 oxidation from 10 to 200 μM. The limit of detection (LOD) was calculated to be 1.27 μM. The selectivity of the sensor was also studied with other biomolecules associated in the human body, and the results showed that interference effect is negligible. Thus, the proposed GNR/Co3O4-modified electrode can be used for H2O2 detection with excellent stability and selectivity.

Graphene Nanoribbons/Manganese Oxide Nanocomposite Modified Electrode for Detection of Antimicrobial Drug Nitrofurantoin

“…Preparation of GNR/MnO 2 Nanocomposite. First, GNRs were prepared as reported elsewhere [33]. From the obtained powder, dispersion of GNRs was prepared with the concentration of 1.5 mg/mL.…”

“…GNR is a 1D material which has been used in the development of battery, supercapacitor, and sensors [32]. Recently, the GNR/Co 3 O 4 nanocomposite-based sensor was prepared for the selective detection of H 2 O 2 [33] and also oxidized GNR showed a good charging capacity of 1,400 mA hr/g in lithium-ion storage [34]. GNR-based sensors were also used to determine epinephrine [32] and nitrogen dioxide [35].…”

Comprehensive Review on Synthesis, Applications, and Challenges of Graphene Quantum Dots (GQDs)

“…The results of the electrochemical study revealed that the electrode with the GNR/Co 3 O 4 coating had a good electrocatalytic activity for the oxidation of H 2 O 2 at 0.925 V. From 10 to 200 M, this sensor responded linearly to H 2 O 2 oxidation. According to calculations, the LOD is 1.27 M [172]. The use of oxygen plasma treatment, which produces oxygenated functions, edge plane sites, and defects, has improved the performance of graphene-based electrochemical sensors.…”

Co3O4 Nanostructured Sensor for Electrochemical Detection of H2O2 as a Stress Biomarker in Barley: Fe3O4 Nanoparticles-Mediated Enhancement of Salt Stress Tolerance

“…Its chemical and electrochemical stability ensures sensor reliability and longevity. Moreover, the cost-effectiveness of Co 3 O 4 and its abundance make it practical for large-scale sensor production [ 70 ]. Additionally, high surface area, achievable through nanostructuring, facilitates increased interaction with analytes, resulting in heightened sensitivity and responsiveness in H 2 O 2 detection.…”