Simultaneous Determination of Benzenediols Isomers Using Copper Nanoparticles/Poly (Glycine)/Graphene Oxide Nanosheets Modified Glassy Carbon Electrode

Abstract

In this research, a new and suitable electrochemical sensor for simultaneous determination of benzenediols (BD) isomers is fabricated by dripping well-dispersed graphene oxide nanosheets (GONs) and in situ plating of poly glycine (P-Gly)-metal copper nanoparticles at the glassy carbon electrode (GCE), Cu-NPs/P-Gly/GONs/GCE, successively. Besides, the as-prepared modified electrode was characterized by scanning electron microscopy (SEM), energy dispersive X-ray spectrometry (EDX), and electrochemical techniques. The proposed electrochemical sensor excellently enhanced the selectivity in the determination of BD isomers by differential pulse voltammetry (DPVs). Compared between the unmodified and modified electrode, unmodified electrode failure to dispel the voltammetric response of BD isomers in a mixture solution, Cu-NPs/P-Gly/GONs/GCE shows larger electrocatalytic activity for the oxidation of hydroquinone (HQ) and catechol (CC) with an enhancement in peak currents and a decrement in peak separation (ΔEp). Consequently, the two isomers can be determined simultaneously. Under the best response experimental, the linear response range was from 3 μM to 200 μM for CC with a detection limit of 1.015 μM and from 2 μM to 300 μM for HQ with a detection limit of 1.067 μM. Further, the suggested sensor was successfully applied for the detection of BD isomers in actual samples.

Simultaneous Determination of Xanthine and Hypoxanthine Using Polyglycine/rGO-Modified Glassy Carbon Electrode

“…With the scanning rate of 100 mV·s −1 , experimental results showed the formation of homogeneous and stable p-Gly/rGO film in −0.45~1.85 V. In Figure 1 , the oxidation current gradually increased during repeated CVs, indicating that p-Gly has been successfully polymerized. The possible mechanism can be explained as follow: When the potential is applied, the surface of GCE is oxidized; At the same time, the amino group on glycine is activated into free radicals, which are connected to the electrode surface through C–N bond, and the activated amino group and the carboxyl group are condensed on the electrode surface and polymerized to form a p-Gly film [ 37 , 38 ].…”

Boosting the charge for the selective photoelectrochemical oxidation of hydroquinone in hazardous environments using a fine-tuned heterojunction catalyst

“…Electrochemicalbased sensors were introduced for the determination of HQ levels in cosmetics using a biomimetic sensor constructed from a Cu-complex, 29 and at the same time other modied surfaces took advantage of the combination of carbon-based materials such as using single-walled carbon nanotubes for the simultaneous sensing of di-hydroxybenzene isomers 30 and employing a rutin multi-walled carbon nanotube-modied glassy carbon electrode. 31 Several investigations employed different surfaces and approaches for the detection of HQ, as follows: core-shell molecular imprinting of polymers, 32 poly(hematoxylin)/TiO 2graphene composite, 33 reduced graphene oxide prepared by thermal methods, 34 modied carbon paste with carbon nano-ber prepared by electro-spinning, 35 nanocomposite made of graphene oxide/mesoporous MnO 2 , 36 poly(3,4ethylenedioxythiophene) doped with carbon nanotubes, 37 modied glassy carbon with successive layers of carbon nanotubes-poly(hydroquinone) and benzo-12-crown-4, 38 graphene oxide nano-sheets followed by polymerization of glycine and nano-Cu particles, 39 electrode modication with CuS nanoglobules, 40 and 2D-graphite carbon nitride nano-sheet/metal nanocomposites. 41 As mentioned in the previous section, PEC combines two driving forces, which work synergistically to enhance the electron transfer kinetics and overcome thermodynamic limitations, i.e., electrochemical and optical energies.…”

Enhanced Electrochemical Response of Isoniazid Electrocatalytic Oxidation on RGO‐PPD‐SiW Modified Electrode

“…Polypeptides were successfully studied as modifiers [20]. The examples of organometallic electrochemical sensors include a copper-based metal-organic frameworks/carbon nitride quantum dots modified pencil graphite electrode (CNQD) [21], wherein the authors state that CNQD have numerous advantages such as large particles, non-toxicity, high stability, low cost, and simple synthesis. The carbon nitride quantum dots are considered as an analog of 2D graphene and are favorable for scientific studies due to great potential use in solar energy conversion, photosynthesis, electro-and photocatalysis.…”