Selective Electrochemical Sensor For Determination Research Articles

Silver nanoparticle–incorporated over-oxidized poly(3,4-ethylenedioxythiophene)-based electrochemical sensor for selective determination of riboflavin

Silver nanoparticle–incorporated over-oxidized poly(3,4-ethylenedioxythiophene)-based electrochemical sensor for selective determination of riboflavin

Plant-based zinc nanoflowers assisted molecularly imprinted polymer for the design of an electrochemical sensor for selective determination of abrocitinib

The first electrochemical sensor application in the literature is described for the sensitive and selective determination of the selective Janus kinase (JAK)-1 inhibitor abrocitinib (ABR). ABR is approved by the U.S. Food and Drug Administration (FDA) for the treatment of atopic dermatitis. The molecularly imprinted polymer (MIP)-based sensor was designed to incorporate zinc nanoflower (ZnNFs)-graphene oxide (GO) conjugate (ZnNFs@GO), synthesized from the root methanolic extract (RME) of the species Alkanna cappadocica Boiss. et Bal. to improve the porosity and effective surface area of the glassy carbon electrode (GCE). Furthermore, the MIP structure was prepared using ABR as a template molecule, 4-aminobenzoic acid (4-ABA) as a functional monomer, and other additional components. Scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR) were used to characterize the surface and structure of the synthesized nanomaterial and MIP-based surface. Among the electrochemical methods, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were preferred for detailed electrochemical characterization, and differential pulse voltammetry (DPV) was preferred for all other electrochemical measurements using 5.0 mM [Fe(CN)6]3–/4– solution as the redox probe. The MIP-based sensor, which was the result of a detailed optimization phase, gave a linear response in the 1.0 × 10–13 – 1.0 × 10–12 M range in standard solution and serum sample. The obtained limit of detection (LOD) and limit of quantification (LOQ) values and recovery studies demonstrated the sensitivity, accuracy, and applicability of the sensor. Selectivity, the most important feature of the MIP-based sensor, was verified by imprinting factor calculations using ibrutinib, ruxolitinib, tofacitinib, zonisamide, and acetazolamide.Graphical

Point-of-care electrochemical sensor for selective determination of date rape drug “ketamine” based on core-shell molecularly imprinted polymer

Misuse of illicit drugs is a serious problem that became the primary concern for many authorities worldwide. Point-of-care (POC) diagnostic tools can provide accurate and fast screening information that helps to detect illicit drugs in a short time. A portable, disposable and reproducible core-shell molecularly imprinted polymer (MIP) screen-printed sensor was synthesized as a POC analyzer for the assay of the date rape drug “ketamine hydrochloride” in different matrices. Firstly, the screen-printed electrode substrate was modified electrochemically with polyaniline (PANI) as an ion-to-electron transducer interlayer to improve the potential signal stability. Secondly, core-shell MIP was prepared, the core consisting of silica nanoparticles prepared by Stober's method, while the MIP shell was synthesized onto silica nanoparticles surface by copolymerizing methacrylic acid functional monomer and the crossing agent; ethylene glycol dimethacrylate in the presence of ketamine as a template molecule. Finally, the core-shell MIP was incorporated into the PVC membrane as an ionophore and drop-casted over PANI modified screen-printed carbon electrode. The imprinting process and the morphology of MIP were examined using scanning electron microscopy, Fourier‐transform infrared and X-ray photoelectron spectroscopic methods. The sensor exhibited a short response time within 3–5 s in a pH range (2.0–5.0). The potential profile indicated a linear relationship in a dynamic concentration range of 1.0 × 10−6 M to 1.0 × 10−2 M with a slope of 54.7 mV/decade. The sensor was employed to determine ketamine in biological matrices and beverages.

Molecularly imprinted polypyrrole based electrochemical sensor for selective determination of ethanethiol

This work describes a molecularly imprinted (MIP) sensor, based on the electropolymerization of pyrrole on a glassy carbon electrode (GCE), for the determination of ethanethiol. Ethanethiol was used as a template molecule for the formation of cavities in the imprinted polymer. The effect of molar ratios template molecules/functional monomers and time needed to remove the template were optimized. The developed MIP/GCE sensor presented a linear range from 6.1 to 32.4 mg L−1 with capability detection and reproducibility values of 7.2 mg L−1 and 10.4%, respectively. The sensitivity of the developed sensor was enhanced by the incorporation of gold nanoparticles (AuNPs). The AuNPs/MIP/GCE showed a capability of detection and reproducibility values of 0.4 mg L−1 and 4.1%, respectively (calibration range from 0.3 to 3.1 mg L−1). The sensor was successfully applied to the determination of ethanethiol in spiked wine samples with recoveries ranging from 99% to 107%.

Ni/N-Doped Graphene Oxide: A Promising Electrochemical Sensor for Selective Determination of Hydroquinone and Catechol

Ni/N-Doped Graphene Oxide: A Promising Electrochemical Sensor for Selective Determination of Hydroquinone and Catechol

Electrochemical behavior of MOF-801/MWCNT-COOH/AuNPs: A highly selective electrochemical sensor for determination of guanine and adenine

In this work, a novel sensor based on gold nanoparticle-modified zirconium-metal-organic frameworks (MOF-801) and carboxyl-functionalized carbon nanotube (MWCNT-COOH) composite material was built successfully for electrochemical detection of guanine and adenine in DNA sample, which exhibits diverse advantages such as fast, convenience and high efficiency. Guanine and adenine were detected by the cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Under the optimal conditions, MOF-801/MWCNT-COOH/ AuNPs/GCE delivered linear DPV responses to guanine in the range of 0.8 ~ 60, 60 ~ 180 μM and the adenine in the range of 0.8 ~ 60, 60 ~ 180 μM with the low detection limit of 0.09 μM for guanine and 0.08 μM for adenine, respectively. The advantages of this method include simplicity, rapidity, high sensitivity, good selectivity as well as low cost. The modified GCE was successfully applied to the analysis of guanine and adenine in DNA samples. • A new electrochemical sensor MOF-801/MWCNT-COOHs/AuNPs/GCE is prepared to simultaneously detecting guanine and adenine. • MWCNT-COOHs and AuNPs greatly improve the conductivity of the sensor and the resulted sensitivity. • This electrochemical sensor has good selectivity and sensitivity.

Construction of polythiophene-derivative films as a novel electrochemical sensor for highly sensitive detection of nitrite.

Herein, a novel, convenient, and highly selective electrochemical sensor for determination of nitrite based on a polythiophene-derivative film-modified glassy carbon electrode (GCE) was established. In this work, 2,5-di-thiophen-3-yl-thiazolo[5,4-d]thiazole (DTT), a novel thiophene derivative, was synthesized and used to form an original and excellent polymer film (PolyDTTF) on GCE through one-step electropolymerization for the first time. The modified electrodes were characterized by electron microscopy (SEM), Fourier transform infra-red spectroscopy (FT-IR), UV-visible spectra, Raman spectroscopy, and electrochemical technologies, in which the electrochemical sensor based on PolyDTTF was successfully constructed and demonstrated a significant electrocatalytic effect on nitrite. The influence of pH value, electrodeposition scanning times, scanning speed, and potential on the electrochemical behavior of nitrite were investigated in detail. Furthermore, the nitrite sensor exhibits excellent responses proportional to nitrite concentrations (R2 = 0.9972) over a concentration range of 5.5 × 10-9 ~ 3.5 × 10-5M with a detection limit (LOD) of 2nM, and has extremely good anti-interference ability for nitrite detection. This proposed sensor can be used to detect nitrite in actual samples, opening the possibility for applications in the food industry and environmental analysis.

Development of an Electrochemical Sensor for Selective Determination of Dopamine Based on Molecularly Imprinted Poly(p‐aminothiophenol) Polymeric Film

AbstractIn this study, a molecularly imprinted electrochemical sensor (MIP/DA) was investigated for selective and sensitive determination of dopamine (DA) by electrochemical polymerization of p‐aminothiophenol in the presence of DA on gold electrode. According to electrochemical behaviour of the sensor, gained through cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), MIP/DA sensor showed distinctive electron transfer characteristics in comparison to the non‐imprinted (NIP/DA) sensor. Besides the MIP/DA sensor showed high selectivity for dopamine through its analyte specific cavities. The sensor had a broad working range of 5.0×10−8–2.0×10−7 M with a limit of detection (LOD) of 1.8×10−8 M and the developed sensor was successfully applied for determination of dopamine in pharmaceutical samples.

A novel electrochemical non-enzymatic glucose sensor based on Au nanoparticle-modified indium tin oxide electrode and boronate affinity

In this article, a sandwich-type electrochemical sensor for selective determination of glucose based on the formation of glucose-boronic bidentate complex has been developed. 3-aminophenylboronic acid (m-APBA) was immobilized on the gold nanoparticles modified ITO electrode with the linker molecule 4-mercaptobenzoic acid (p-MBA). Then, glucose was captured by boronic acid group from m-APBA as the primary receptor and further grafted with an electroactive ferroceneboronic acid (FcBA) as the secondary receptor to form the sandwich-type sensor for selective detection of glucose. For comprehensively understanding the effect of the charge and structure of the terminal boronic acid group of 3-APBA on its binding to glucose, surface pKa was studied by electrochemical titration method, and it was proved the feasibility of examining glucose in physiological condition by the sandwich-type electrochemical sensor. The electrochemical characteristics of the as-prepared sensor were investigated by using electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The electrochemical sensor displayed a linear detection range of glucose from 0.5 mmol L−1 to 30 mmol L−1, with detection limit of 43 µmol L−1. The sensor exhibited good performance in selectivity study with the coexistence of galactose, fructose, mannose and other common interferences in physiological environment, such as, uric acid, ascorbic acid and dopamine. The as-prepared electrode with high sensitivity, good stability and reproducibility as well as excellent biocompatibility made it promising for the development of enzyme-free sensors.

Electrochemical sensor for selective tyramine determination, amplified by a molecularly imprinted polymer film

A molecularly imprinted polymer (MIP) film based electrochemical sensor for selective determination of tyramine was devised, fabricated, and tested. Tyramine is generated in smoked and fermented food products. Therefore, it may serve as a marker of the rottenness of these products. Importantly, intake of large amounts of tyramine by patients treated with monoamine oxidase (MAO) inhibitors may lead to a “cheese effect”, namely, a dangerous hypertensive crisis. The limit of detection at S/N = 3 of the chemosensor, in both differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS) determinations, with the use of the Fe(CN)64-/Fe(CN)63- redox probe, was 159 and 168 µM tyramine, respectively. The linear dynamic concentration range was 290 µM to 2.64 mM tyramine. The chemosensor was highly selective with respect to the glucose, urea, and creatinine interferences. Its DPV determined apparent imprinting factor was 5.6. Moreover, the mechanism of the “gate effect” in the operation of the polymer film-coated electrodes was unraveled.

Electrochemical determination of hydrazine in surface water on Co(OH)2 nanoparticles immobilized on functionalized graphene interface

Still the whole world is straggling for the pure surface water monitoring which is time consuming and expensive work. Thus, a quick, selective and authentic measuring tool is anticipated for continuous monitoring the addition of chemical contaminants, such as hydrazine (N2H4). In this study, we have developed a Co(OH)2 nanoparticles decorated benzaldehyde-functionalized graphene (denoted as RGO/DHB/Co(OH)2) electrochemical sensor for selective determination of N2H4 from surface water. The electrochemical experiments are signifying its potential catalytic activity towards the oxidation of N2H4. Amperometric response suggests that this electrode can perform at the broad linear concentration range from 5 to 1700 µM at a lower limit of detection of 0.165 µM with good sensitivity of 1446.82µA mM−1cm−2 by <2 s. The RGO/DHB/Co(OH)2 exhibits nonsignificant interference during N2H4 detection in presence of several interferents such as primary amines, biomolecules and some common anions/cations. The admirable stability, repeatability, reproducibility and trace-level detection of N2H4 in various surface water samples have proven that the RGO/DHB/Co(OH)2 is an efficient tool for real-time application towards N2H4 detection and can contribute its potentiality against the current worldwide pandemic COVID-19. Importantly, the reaction mechanism of N2H4 oxidation has revealed at the RGO/DHB/Co(OH)2 surface by easy demonstration.

Facile Preparation of In-Situ S-Doped Flake Carbon Materials from Metal-Organic Frameworks and Its Application in Electrochemical Detection of Hg (II)

S-doped carbon materials have recently attracted much attention as electrode materials for electrocatalysis and sensors applications. Herein, we report a facile route for the preparation in situ of flake S-doped carbon nanomaterial by using plate-like sulfur-containing metal-organic frameworks (MOFs) as a pyrolytic precursor without additional carbon and sulfur sources. The resultant MOFs-derived carbon (denoted as PSMC) was further characterized and analyzed by scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and Raman spectroscopy. Then a highly sensitive electrochemical sensor for selective determination of Hg (II) was achieved by designing PSMC as the active electrode material. The sensitivity of Hg (II) at the sensor is 2.12[Formula: see text][Formula: see text]A[Formula: see text]ppb[Formula: see text][Formula: see text]cm[Formula: see text] according to the slope of the calibration plot and electrode area. Finally, the PSMC-based sensor was proved feasible in river water sample analyses. This work may also provide a valuable clue for the preparation of flake S-doped carbon sensing material as a new application of MOFs-based materials.¡abs¿

A novel electrochemical sensor for selective determination of theophylline in pharmaceutical formulations

Theophylline (TPN) is a medication commonly used in treatment of chronic asthma disorder. However, it is associated with a number of known troublesome side effects, hence, the need to monitor its concentration levels in pharmaceutical formulations. In this work, a nanocomposite based on ZnONPs – MWCNTs – Cyt c (zinc oxide nanoparticles – multiwalled carbon nanotubes – Cytochrome c) were used in the modification of a highly sensitive electrochemical sensor for quantification of TPN in pharmaceutical formulations. The synthesized ZnONPs, ZnONPs-MWCNTs and ZnONPs-MWCNTs-Cyt c were characterized using Thermogravimetric analysis (TGA), Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), Transmission electron microscopy (TEM), surface area analysis by Brunauer–Emmett–Teller (BET) and electrochemical impedance spectroscopy (EIS). Cyclic voltammetry was employed to study electro-catalytic properties of ZnONPs-MWCNTs-Cyt c-GCE towards oxidation of TPN. The dependence of peak currents and potentials on scan rates and pH were also investigated and the working parameters were optimized. Remarkably, ZnONPs-MWCNTs-Cyt c-GCE exhibited improved anodic peak currents as compared to ZnONPs-MWCNTs-GCE, MWCNTs-GCE and bare GCE for 0.1 M TPN at 1.0 V vs. Ag/AgCl. The linear range of the established electrochemical biosensor was from 0.4 to 15 µM (R2 = 0.9903) with detection limit of 0.0012 µM, thus making it a better candidate for the detection of TPN in pharmaceutical formulation.

Graphene/iridium(III) dimer complex composite modified glassy carbon electrode as selective electrochemical sensor for determination of hydroquinone in real-life water samples

ABSTRACT A novel electrochemical sensor for sensitive and selective detection of hydroquinone (HQ) was developed using graphene/iridium(III) dimer complex composite modified glassy carbon electrode (graphene/Ir(III) complex/GCE). The composite was characterised by field emission scanning electron microscopy, energy dispersive X-ray microanalysis, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The graphene/Ir(III) complex/GCE has provided higher surface area which was good for catalytic activity and enhanced electrical conductivity that was then examined using differential pulse voltammetry, cyclic voltammetry, and square wave voltammetry. At optimal condition, HQ has been sensitively detected in the ranges of 100–1.5 µM and 1.5–0.05 µM with good sensitivity of 1120.64 μA/mM/cm2 and low detection limit of 1.1 nM (S/N = 3). The graphene/Ir(III) complex/GCE sensor presented the performance advantages of good reproducibility, repeatability, stability and selectivity. The prepared electrode was further applied to detect HQ in real-life water samples, which exhibit the acceptable recovery.

Copper oxide, ionic liquid and Mn(III) Salen modified carbon paste electrode as selective electrochemical sensor for determination of droxidopa in the presence of carbidopa

A novel electrochemical sensor for the selective and sensitive detection of droxidopa in presence of carbidopa at physiological pH was developed by the bulk modification of carbon paste electrode (CPE) with copper oxide (CuO), ionic liquid and Mn (III) salen (CuO-IL-MS/CPE). Large peak separation, good sensitivity and stability allow this modified electrode to analyze droxidopa individually and in the presence of carbidopa. Applying differential pulse voltammetry (DPV), a linear dynamic range of 0.5-600.0 µM with detection limit of 0.2 µM was obtained for droxidopa. Finally, the proposed method was applied to the determination of droxidopa and carbidopa in real samples.

Electrochemical Detection of Eugenol (EU) Using Polyacrylonitrile Molecular Imprinted Polymer Embedded Graphite (PAN-MIP/G) Electrode

In this paper, development of a polyacrylonitrile molecularly imprinted polymer embedded graphite (PAN-MIP/G) electrode is described and its use as a sensitive and selective electrochemical sensor for determination of Eugenol (EU) in various food ingredients. The pure polyacrylonitrile is found to be the most efficient polymer material in comparison with other compositions involving acrylo-acid, acrylamide, acrylate esters and their mixtures. The PAN-MIP/G electrode shows three different linear determination ranges: 0.0005- $1.0~\mu $ , 1- $50~\mu $ and 50- $160~\mu $ with lowest detection limit of $0.0004~\mu \text{M}$ . PAN-MIP/G is characterized by field emission scanning electron microscope (FESEM) and fourier transform infra-red (FTIR) spectroscopy. The effect of variables such as electrolytes, pH and scan rate are optimized to get highest sensitivity. The PAN-MIP/G electrode shows good repeatability, reproducibility and excellent sensitivity towards EU. The effects of common interferences on the EU peak current are studied. Furthermore, the developed electrode is successfully applied for the determination of EU in curry powder, clove powder and capsule samples.

Molecularly imprinted polypyrrole based electrochemical sensor for selective determination of 4-ethylphenol

This work describes the development of an electrochemical sensor based on a molecularly imprinted polymer (MIP) for sensitive and selective determination of 4-ethylphenol in wine. The sensor has been built by means of the electrosynthesis of the MIP on a glassy carbon electrode surface using cyclic voltammetry. The electropolymerization has been performed in the presence of 4-ethylphenol and pyrrole as template molecule and functional monomer, respectively. The influence of the molar ratios of template molecules to functional pyrrole monomers and the time needed to remove the template have been optimized taking into account the differential pulse voltammetric response of 4-ethylphenol. Under the optimal experimental conditions the developed MIP/GCE sensor shows good capability of detection (0.2 μM, α = β = 0.05) and reproducibility (3.0%) in the concentration range from 0.2 to 34.8 μM. The influence of possible interfering species in the analytical response has been studied and the sensor has successfully been applied to the determination of 4-ethylphenol in different wine samples.

A novel electrochemical sensor based on carbon nanotubes array for selective detection of dopamine or uric acid

A novel single-walled carbon nanotubes array-modified glassy carbon electrode (SWCNTs array-GCE) has been fabricated through a simple electrochemical technique. Benefitting from their vertically aligned configuration on the electrode surface, the modified single-walled carbon nanotubes can be used more efficiently in comparison with other modified method. The as-fabricated SWCNTs array-GCE can separate the anodic oxidation potential of dopamine (DA), uric acid (UA) and ascorbic acid (AA) with well-defined peak separation in the presence of each other, and thus employs as a new electrochemical sensor for selective determination of DA and UA. It can make a further improvement of the electrocatalytic ability of the electrode to perform an acetone pretreatment to SWCNTs array-GCE before electrochemical detection, which has been confirmed by atomic force microscope and electrochemical impedance spectroscopic measurements. Especially, unlike other carbon nanotubes-based electrode at which only two redox pairs are observed for dopamine oxidations, a third two-electron oxidation of 5,6-dihydroxyindole to indole-5,6-quinone can be clearly observed at acetone-pretreated SWCNTs array-GCE, showing the excellent electrocatalytic performance of as-fabricated electrode toward dopamine. The practicability of SWCNTs array-GCE was evaluated for the selective detection of DA and UA in real sample solutions of human serum and urine. It revealed acceptable recovery results in the range of 94–104%, indicating that it might be a promising platform for further biosensor development.

Voltammetric sensing of dopamine based on a nanoneedle array consisting of NiCo2S4 hollow core-shells on a nickel foam.

An array consisting of homogeneous NiCo2S4 hollow core-shell nanoneedles was fabricated and is shown to enable sensitive electrochemical determination of dopamine (DA). The array was grown directly on a nickel foam (NF) substrate by a two-step hydrothermal process. The hierarchical nanoarray consists of a homogeneous NiCo2S4 nanoneedle core and a NiCo2S4 nanosheet shell. A 3-dimensional micro/nano structure is formed due to the presence of the micropores ofthe NF. The electrode was characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. Compared to a plain NF electrode, the NiCo2S4-modified NF electrode displays higher electrocatalytic activity for the oxidation of DA by differential pulse voltammetry (DPV). The sensor, best operated at a typical working voltage of 134mV (vs. saturated calomel electrode), has a linear response in the 0.5-100μM DA concentration range and a 0.2μM detection limit (at S/N = 3). The electrode is selective over ascorbic acid and uric acid. Graphical abstract Schematic presentation of an electrochemical sensor for selective determination of dopamine based on the use of ahomogeneous NiCo2S4 hollow core-shell nanoneedle array on nickel foam.

An ultrasensitive and selective electrochemical sensor for determination of estrone 3-sulfate sodium salt based on molecularly imprinted polymer modified carbon paste electrode.

A highly sensitive and selective electrochemical sensor based on carbon paste electrode (CPE) modified with molecularly imprinted polymers (MIPs) has been developed for the determination of estrone 3-sulfate sodium salt (ESS). MIPs were prepared in polar medium via bulk polymerization and characterized by scanning electron microscopy and infrared spectroscopy. Cyclic voltammetry was performed to the study preparation process and binding behavior of the MIP-modified CPE (MIP/CPE) toward ESS. The conditions for preparing MIPs and MIP/CPE as well as ESS detection were optimized. Under the optimal experimental conditions, the detection linear range for ESS is 4×10-12 to 6×10-9M with a limit of detection of 1.18×10-12M (S/N=3). In addition, the sensor exhibits high binding affinity toward ESS over its structural analogues with excellent repeatability and stability. The fabricated MIP/CPE was then successfully employed to detect ESS in pregnant mare urine (PMU) without any pretreatment, and the average recoveries were from 99.6 to 104.9% with relative standard deviation less than 3.0%. High-performance liquid chromatography was adopted as a reference to validate the established approach in detecting ESS and their results showed good agreement. The as-prepared sensor has high potential to be a decent tool for on-site determination of ESS in PMU in a fast and convenient manner. Graphical Abstract ᅟ.