A Nanostructure Based Electrochemical Sensor for Square Wave Voltammetric Determination of L‐Cysteine in the Presence of High Concentration of Folic Acid

Abstract

This study describes the development, electrochemical characterization and utilization of 8,9‐dihydroxy‐7‐methyl‐12H‐benzothiazolo [2,3‐b]quinazolin‐12‐one (DMBQ)/ZnO nanoparticles (ZnO/Nps)‐carbon paste electrode (DMBQ/ZnO/NPs/CPE) as a modified sensor for the electrocatalytic determination of cysteine (Cys) in the presence of folic acid (FA). ZnO/NPs was synthesized and characterized by X‐ray diffraction (XRD) method. The prepared DMBQ/ZnO/NPs/CPE was developed as a highly sensitive voltammetric sensor for determination of Cys in the presence of FA in real samples. Square wave voltammetry (SWV) of Cys exhibited linear dynamic range with a detection limit (3σ) of 0.05 µmol/L.

Photoelectrochemical Detection of L‐Cysteine with a Covalently Grafted ZnTAPc‐Gr‐based Probe

“…The linear equation is expressed as ΔI (μA/cm −2 )=−2.21×10 −2 C (μM)+15.68, and R 2 =0.9960, with a limit of detection (LOD) of 11.4 nM (LOD=3.3 σ/S , where σ is the standard deviation of the 11 measurements of the blank current and S is the slope of the linear equation). Compared with other methods for the detection of L‐cysteine (Table ) , the newly designed ZnTAPc‐Gr‐modified ITO electrode exhibits relatively high sensitivity, wide linearity range, low detection limit, and excellent reproducibility.…”

Liquid phase determination of bisphenol A in food samples using novel nanostructure ionic liquid modified sensor

“…Room temperature ionic liquids can be used to make different modified sensors, which could increase the electron transfer rate of electroactive compounds [30][31][32][33].…”

l -Cysteine determination in embryo cell culture media using Co (II)-phthalocyanine modified disposable screen-printed electrodes

“…Specifically, L-CySH is one of the non-essential amino acids, which presents a crucial role in regulating the biological activity of proteins [2] and protecting cells against free radicals (in the cellular antioxidant defense system) [3]. L-CySH deficiency has been related to some pathologies as syndrome of slow growth in children, liver damage, edema, muscle loss, skin lesion and neurodegenerative diseases, among others [1,[4][5][6][7].…”

“…Within the field of electroanalysis, previous studies describe that bare carbonaceous materials and conventional metallic electrodes (Au, Pt) usually exhibit high overpotentials for the electrooxidation of L-CySH due mainly to a sluggish electron transfer kinetic and, consequently, they exhibit short linear range concentration and low selectivity for LCySH determination [25][26][27]. To overcome these problems, various chemically modified electrodes (CMEs) and biosensors with electrocatalytic properties have been developed and applied for a superior determination of L-CySH [1][2][3][4][5][6][28][29][30][31][32][33][34]. In this sense, different types of materials have been employed to modify electrodes surface, e.g.…”

“…In this sense, different types of materials have been employed to modify electrodes surface, e.g. carbon based nanomaterials [3,4,29], metal and metal oxide nanoparticles [5,6,27,30], graphene oxides [6], nanostructures of different compounds [31,34,35], conductive polymers [31,33,34] and metallophthalocyanines [1]. More particularly, metallophthalocyanines (MPc, where M: Co, Cu, Zn, Fe) exhibit excellent electronic properties, and potential applications in electrocatalysis towards sulfhydryl compounds electrooxidation [2,32,[36][37][38].…”