•Electrochemical behaviour of Sudan I study using novel modified carbon paste electrode.•Synthesis and application of Pt/CNTs as novel sensor for Sudan I determination.•This novel sensor is also used ...for the determination of Sudan I in food samples.
In this work, a simple and high sensitivity electrochemical sensor was developed to determine Sudan I based on Pt/CNTs nanocomposite ionic liquid modified carbon paste electrode (Pt/CNTs/ILCPE) using cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and square wave voltammetry (SWV) methods. The novel sensor exhibited an obviously catalytic activity towards the oxidation of Sudan I, which can be confirmed by the increased oxidation peak current and the decreased oxidation peak potential when compared with the bare carbon paste electrode (CPE). The electron transfer coefficient (α), diffusion coefficient (D), and charge transfer resistance (Rct) of Sudan I at the modified electrode were calculated. The linear response range and detection limit were found to be 0.008–600μmolL−1 and 0.003μmolL−1, respectively. Other species did not interfere with the determination of Sudan I at a surface of propose sensor in the optimum condition. The proposed sensor was successfully applied for the determination of Sudan I in food samples with satisfactory results.
•Electrochemical behaviour of bisphenol A study using novel modified carbon paste electrode.•Synthesis and application of ZnO/CNTs as novel sensor for bisphenol A determination.•The sensor resolved ...the overlap of bisphenol A and Sudan I.
The electrochemistry of bisphenol A (BPA) was studied by voltammetric methods at a surface of carbon paste electrode modified by a ZnO/CNTs nanocomposite and room-temperature ionic liquid of 1,3-dipropylimidazolium bromide. The ratio of ZnO/CNTs and ionic liquid (IL) on the surface of the electrode has to be controlled carefully because the charging currents. The anodic peaks of BPA and Sudan I in their mixture can be well separated. At pH 7.0 the two peaks are separated ca. 0.47 and 0.70V, respectively; hence BPA can be determined in the presence of Sudan I and more than 8.7 times current excess of BPA. The peaks current of square wave voltammograms (SWV) of BPA and Sudan I increased linearly with their concentration in the ranges of 0.002–700μmolL−1BPA and 0.2–800μmolL−1Sudan I. The detection limits for BPA and Sudan I were 9.0nmolL−1 and 80nmolL−1, respectively. The modified electrode has been successfully applied for the assay of BPA in food samples. This study provides a simple and easy approach to selectively detect BPA in the presence of Sudan I.
Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal. Because of their multifunctional ...characteristics,
e.g.
, simplistic synthesis, acceptable environmental stability, beneficial optical, electronic, and mechanical features, researchers have largely considered them for diverse applications. Therefore, their capability of catalyzing several electrode reactions has been introduced as one of their significant features. A thin layer of the conducting polymer deposited on the substrate electrode surface can augment the electrode process kinetics of several solution species. Such electrocatalytic procedures with modified conducting polymer electrodes can create beneficial utilization in diverse fields of applied electrochemistry. This review article explores typical recent applications of conductive polymers (2016-2020) as active electrode materials for energy storage applications, electrochemical sensing, and conversion fields such as electrochemical supercapacitors, lithium-ion batteries, fuel cells, and solar cells.
Scientists have categorized conductive polymers as materials having strongly reversible redox behavior and uncommon combined features of plastics and metal.
This study is on current developments concerning ferrocene (FC) and its derivatives on the basis of electrochemical biosensors and sensors. The distinct physiochemical characteristics of FC have ...enabled the development of new sensor devices, specifically electrochemical sensors. Several articles have focused on the implementation of FC as an electrode constituent while discussing its electrochemical behavior. Furthermore, typical FC-design-based biosensors and sensors are considered as well as practical examples. The favorable design of FC-based biosensors and general sensors needs adequate control of their chemical and physical characteristics in addition to their surface immobilization and functionalization.
Wood ash is a naturally alkaline derived substance containing organic and inorganic constituents. This study investigates the catalytic activity of wood ash as a heterogeneous catalyst for the ...synthesis of benzochromene derivatives. Several wood ash catalysts, comprising calcium- and potassium-rich carbonates, were prepared from different natural resources under various combustion temperatures. The prepared catalysts were characterized by Fourier transform infrared, scanning electron microscopy, energy dispersive X-ray analysis, transmission electron microscopy, and X-ray diffraction techniques. Catalytic efficiency of the resultant catalysts was tested in the synthesis of benzochromene derivatives. The experimental studies clarified that the catalyst prepared at 850 °C could efficiently expedite the formation of three-component synthesis of benzochromene derivatives in water at 80 °C with high yields. Indeed, alkali, alkaline metal, and metal oxides such as Al
O
, SiO
, MgO, CaO, and Fe
O
, are widely utilized as both catalyst and catalyst support in the heterogeneous catalytic processes. The prepared wood ash catalysts (possessing metal oxides, e.g., CuO, Al
O
, SiO
, and CaO) could effectively prompt the electrophilic activity of the carbonyl groups during the nucleophilic attack intermediate, enhancing the efficiency of the reactions.
A screen-printed electrochemical sensor based on Fe3O4@cellulose nanocrystals/Cu nanocomposite (Fe3O4@CNC/Cu) has been constructed for the sensitive detection of venlafaxine. The magnetic ...Fe3O4@cellulose nanocrystal/Cu nanocomposite was prepared by a green procedure using a plant extract (Petasites hybridus leaf) as a stabilizing and reducing agent for copper. The formation of Fe3O4@CNC/Cu was validated through X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, ultraviolet–visible spectral analysis, vibrating sample magnetometer, and thermal analysis. Fe3O4@CNC/Cu was next used for modifying a graphite screen-printed electrode, intended for the analysis of venlafaxine concentration. The electrochemical behavior of venlafaxine on the resulting electrode was evaluated through cyclic and differential pulse voltammetry and chronoamperometry. The tests indicated that the sensor has good performance for the electrochemical detection of venlafaxine. Under optimized conditions, the linear dynamic range for venlafaxine concentrations by the modified electrode was 0.05–600.0 μM, and the limit of detection was 0.01 μM. In addition, the developed technique was also demonstrated as a selective, easy, and precise sensor to identify venlafaxine in urine, water, and pharmaceutical formulation samples.
The electrocatalytic oxidation of ascorbic acid (AA) has been studied by
p
-aminophenol modified carbon nanotubes paste electrode (APMCNTPE). Cyclic voltammetry (CV) and chronoamperometry were used ...to investigate the suitability of AP as a mediator for the electrocatalytic oxidation of AA in aqueous solution. The oxidation of AA occurs at a potential about 320 mV less positive than with the unmodified carbon paste electrode at pH 7.0. The catalytic reaction rate constant, k
h
was calculated (2.257 × 10
3
M
−1
s
−1
) using chronoamperometry. The differential pulsevoltammetric (DPV) peak currents of the electrode increased linearly with the corresponding AA concentration in the range of 2.0 × 10
−7
M – 1.2 × 10
−4
M with a detection limit of 8.0 × 10
−8
M. The influence of pH and potential interfering substances on the determination of AA were studied. Finally, the proposed method was also examined as a selective, simple and precise electrochemical sensor for the determination of AA in real samples such as fruit juices and fresh vegetable juice.
The voltammetric behavior of doxorubicin at a ZnO nanoparticle/1-butyl-3-methylimidazolium tetrafluoroborate modified carbon paste electrode (ZnO-NPs/BMTFB/CPE) has been investigated. For the goal, ...ZnO-NPs were biosynthesized by celery extract in aqueous solution. The ZnO-NPs/BMTFB/CPE exhibits a good promoting effect on the oxidation response of doxorubicin. After optimization of pH condition, ZnO-NPs/BMTFB/CPE exhibits two separated oxidation signals for simultaneous analysis of doxorubicin and dasatinib with ∆E ~300 mV. The oxidation currents showed linear relation with doxorubicin or dasatinib concentration in the ranges of 0.07–500 μM and 1.0–1200 μM, respectively. We detected limit of detection 9.0 nM and 0.5 μM for doxorubicin and dasatinib, respectively. The ZnO-NPs/BMTFB/CPE has been applied to the analysis of doxorubicin and dasatinib in injection and pharmaceutical serum samples.
In this paper, we suggest a novel electrochemical sensor based on carbon paste electrode modified with ZnO-NPs and ionic liquid for simultaneous analysis of doxorubicin and dasatinib as two important anticancer drugs for the first time. Display omitted
•Biosynthesis of ZnO-NPs using celery extract for the first time•Synergistic effect of ZnO-NPs and ionic liquid for modification of electrode•First report for simultaneous determination of doxorubicin and dasatinib two anticancer drugs
An efficient and selective synthesis of substituted chromene derivatives via three-component reaction of 4-hydroxycoumarin or 1,3-dicarbonyl compounds, activated acetylenic compounds and ...N-nucleophiles is described. The reaction was conducted under solvent-free conditions at 70°C using potassium fluoride impregnated on natural zeolite as a cheap and available solid base. The procedure has several advantages involving selectivity, excellent yields and a convenient work-up method.
A high-quality method for one-pot biosynthesis of silver nanoparticles (AgNPs) using onion extracts as reductant and stabilizer is reported. The synthesized AgNPs were characterized by ...ultraviolet-visible spectroscopy (UV-Vis), X-ray powder diffraction (XRD), and transmission electron microscopy (TEM). UV-Vis spectroscopy results showed that the AgNP absorption band was located at a peak of 397 nm in aqueous solution. Both XRD and TEM results confirmed that the AgNPs were mainly spherical with average diameters of 6.0 nm by TEM and about 5.3–10.2 nm calculated using XRD data. The ability of AgNPs to reduce charge transfer resistance was also investigated using electrochemical impedance spectroscopy. Finally, the effect of synthesized NPs on ascorbic acid signal was investigated by square wave voltammetry. The peak current of square wave voltammograms of ascorbic acid increased linearly with its concentration in the range of 0.4–450.0μM. The detection limit for ascorbic acid was 0.1μM.
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