Voltammetric behavior and the determination of quercetin at a flowerlike Co3O4 nanoparticles modified glassy carbon electrode

Abstract

Flowerlike Co 3 O 4 nanoparticles were used as a modifier on the glassy carbon electrode to fabricate a quercetin (Qu) sensor. The morphology and crystallinity of the prepared Co 3 O 4 material were investigated by scanning electron microscopy and X-ray diffraction. Electrochemical behavior of Qu at the sensor was studied by cyclic voltammetry and semi-derivative voltammetry. Results suggested that the modified electrode exhibited a strong electrocatalytic activity toward the redox of Qu. The electron transfer coefficient (a), the number of electron transfer (n), and the diffusion coefficient (D) of Qu at the sensor were calculated. Under the optimum conditions, the catalytic peak currents of Qu were linearly dependent on the concentrations of Qu in the range from 5.0 9 10 -7 to 3.3 9 10 -4 M, with a detection limit of 1.0 9 10 -7 M. This proposed method was successfully applied to determine the quercetin concentration in Ginkgo leaf tablet and human urine samples.

Semi-differential analysis of irreversible voltammetric peaks

“…Various electrochemical processes, such as redox reactions with reduced and oxidised species present in the same phase [6,14,[21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], adsorption on surfaces of electrodes [36][37][38], electrodeposition [39][40][41][42][43][44][45][46][47][48] or electrodissolution [49][50][51] were analysed by means of semi-differentiation or semi-integration. The most extensive mathematical treatment related to these methods was applied to the electrochemical reactions were both oxidised and reduced form are soluble in the electrolyte phase and their transport proceeds under conditions of semi-infinite linear diffusion [4].…”

A Molecularly Imprinted Polymer with Incorporated Graphene Oxide for Electrochemical Determination of Quercetin

“…Recently, multiwall carbon nanotubes-modified electrodes have been found to be excellent electrodes for the determination of quercetin at trace levels due to their strong surface adsorption [19–21]. Electrodes modified with metal or metallic compounds are also used in quercetin detection [22–24]. …”

Graphene nanosheets as a sensing platform for amplified electrochemical measurement of quercetin and uric acid in biological fluids

“…Because electron transfer number (n) is 2 for two molecules, it may be assumeed that the electrode reaction of Qu and UA at the proposed modified electrode was accompanied by two protons and two electrons. 11,35 The electrooxidation mechanisms of Qu and UA at the GNSs/GCE are illustrated in Scheme 1.…”

“…Qu has been shown to act as a scavenger of various oxidizing species such as superoxide anions, hydroxyl radicals, and peroxyl radicals. 11 Most of the studies have revealed various beneficial effects on human health including antiviral, anticancer, antiinflammatory, and antitumor activity and can protect human DNA from oxidative attack in vitro. Therefore, the redox potential of Qu is an important factor that has effected biological behavior.…”