Simple, Low-Cost and Sensitive Electrochemical Sensing of Antineoplastic Drug Amethopterin Based on Nanocarbon Black Modified Electrode

In this paper, the development of a nanoporous TiO2 array-modified Ti electrode for photo-electrochemical (PEC) sensing of dopamine (DA) is reported. A porous TiO2 array-modified electrode was fabricated from the controlled anodic oxidation of a Ti working electrode of commercial screen-printed electrodes (SPE). The anodization process and the related morphological and microstructural transformation of the bare Ti electrode into a TiO2/Ti electrode was followed by scanning electron microscopy (SEM) and UV-visible reflectance spectroscopy (DR-UV-Vis). The modified electrode was irradiated with a low-power (120 mW) UV-Vis LED lamp (λ = 400 nm) and showed good performance for the detection of DA with a large linear response range, a sensitivity of 462 nA mM−1 cm−2, and a limit of detection of 20 µM. Moreover, it showed higher photocurrents in the presence of DA in comparison to some foreign species such as ascorbic acid, uric acid, glucose, K+, Na+, and Cl−. Thus, this proposed low-cost photo-electrochemical sensor, with the advantage of very simple fabrication, demonstrates potential applications for the determination of dopamine in real samples.

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Paper-Based Competitive Immunochromatography Coupled with an Enzyme-Modified Electrode to Enable the Wireless Monitoring and Electrochemical Sensing of Cotinine in Urine

Sensors ◽

10.3390/s21051659 ◽

2021 ◽

Vol 21 (5) ◽

pp. 1659

Author(s):

Nutcha Larpant ◽

Pramod K. Kalambate ◽

Tautgirdas Ruzgas ◽

Wanida Laiwattanapaisal

Keyword(s):

Glucose Oxidase ◽

Modified Electrode ◽

Near Field ◽

Electrochemical Measurement ◽

Electrochemical Sensing ◽

Urine Samples ◽

Lateral Flow Strip ◽

Wireless Monitoring ◽

Sensing Platform ◽

Combined Strategy

This paper proposes a combined strategy of using paper-based competitive immunochromatography and a near field communication (NFC) tag for wireless cotinine determination. The glucose oxidase labeled cotinine antibody specifically binds free cotinine in a sample, whereas the unoccupied antibody attached to BSA-cotinine at the test line on a lateral flow strip. The glucose oxidase on the strip and an assistant pad in the presence of glucose generated H2O2 and imposed the Ag oxidation on the modified electrode. This enabled monitoring of immunoreaction by either electrochemical measurement or wireless detection. Wireless sensing was realized for cotinine in the range of 100–1000 ng/mL (R2 = 0.96) in PBS medium. Undiluted urine samples from non-smokers exhibited an Ag-oxidation rate three times higher than the smoker’s urine samples. For 1:8 diluted urine samples (smokers), the proposed paper-based competitive immunochromatography coupled with an enzyme-modified electrode differentiated positive and negative samples and exhibited cotinine discrimination at levels higher than 12 ng/mL. This novel sensing platform can potentially be combined with a smartphone as a reader unit.

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Molecularly Imprinted Polymers Combined with Electrochemical Sensors for Food Contaminants Analysis

Molecules ◽

10.3390/molecules26154607 ◽

2021 ◽

Vol 26 (15) ◽

pp. 4607

Author(s):

Dounia Elfadil ◽

Abderrahman Lamaoui ◽

Flavio Della Pelle ◽

Aziz Amine ◽

Dario Compagnone

Keyword(s):

Food Safety ◽

Molecularly Imprinted Polymers ◽

Electrochemical Sensors ◽

Low Cost ◽

Electrochemical Analysis ◽

Ease Of Use ◽

Electrochemical Sensing ◽

Food Contaminants ◽

Molecularly Imprinted ◽

Imprinted Polymers

Detection of relevant contaminants using screening approaches is a key issue to ensure food safety and respect for the regulatory limits established. Electrochemical sensors present several advantages such as rapidity; ease of use; possibility of on-site analysis and low cost. The lack of selectivity for electrochemical sensors working in complex samples as food may be overcome by coupling them with molecularly imprinted polymers (MIPs). MIPs are synthetic materials that mimic biological receptors and are produced by the polymerization of functional monomers in presence of a target analyte. This paper critically reviews and discusses the recent progress in MIP-based electrochemical sensors for food safety. A brief introduction on MIPs and electrochemical sensors is given; followed by a discussion of the recent achievements for various MIPs-based electrochemical sensors for food contaminants analysis. Both electropolymerization and chemical synthesis of MIP-based electrochemical sensing are discussed as well as the relevant applications of MIPs used in sample preparation and then coupled to electrochemical analysis. Future perspectives and challenges have been eventually given.

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A facile synthesis of novel polyaniline/graphene nanocomposite thin films for enzyme-free electrochemical sensing of hydrogen peroxide

Molecular Systems Design & Engineering ◽

10.1039/d1me00130b ◽

2021 ◽

Author(s):

Swati Verma ◽

Dipendra Singh Mal ◽

Paulo R. Oliveira ◽

Bruno Campos Janegitz ◽

Jai Prakash ◽

...

Keyword(s):

Thin Films ◽

Hydrogen Peroxide ◽

Small Molecules ◽

Present Article ◽

Electrochemical Method ◽

Electrochemical Sensing ◽

Facile Synthesis ◽

Nanocomposite Thin Films ◽

Graphene Nanocomposite

Electrochemical method is the most effective, facile, and economical approach for the detection of small molecules. The present article deals with design and engineering of polymer-graphene based thin films through...

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A new strategy for enhancing electrochemical sensing from MWCNTs modified electrode with Langmuir-Blodgett film and used in determination of methylparaben

Sensors and Actuators B Chemical ◽

10.1016/j.snb.2015.01.056 ◽

2015 ◽

Vol 211 ◽

pp. 332-338 ◽

Cited By ~ 21

Author(s):

Lu Wang ◽

Yinfeng Li ◽

Gaiping Li ◽

Baoxian Ye

Keyword(s):

Modified Electrode ◽

Electrochemical Sensing ◽

Blodgett Film ◽

Langmuir Blodgett ◽

New Strategy ◽

Langmuir Blodgett Film

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Molybdenum Trioxide Dihydrate-Graphene Composite for Electrochemical Detection of Thiourea Molecule

NANO ◽

10.1142/s1793292016500363 ◽

2016 ◽

Vol 11 (03) ◽

pp. 1650036 ◽

Cited By ~ 2

Author(s):

Xinmeng Zhang ◽

Kezhi Li ◽

Hejun Li ◽

Jinhua Lu ◽

Leilei Zhang

Keyword(s):

Electrochemical Sensor ◽

Modified Electrode ◽

Molybdenum Trioxide ◽

Electrochemical Sensing ◽

Carbon Electrode ◽

X Ray ◽

Glass Carbon Electrode ◽

Graphene Composite ◽

Relative Standard ◽

Glass Carbon

A novel electrochemical sensing platform was constructed based on a facile self-assembly procedure synthetic laminar molybdenum trioxide dihydrate (MoO[Formula: see text]H2O)-graphene composite. Field emission scanning electron microscopy (FESEM), X-ray spectroscopy, X-ray diffraction (XRD) and Raman spectroscopy were employed to characterize the morphology and composition of the MoO[Formula: see text]H2O-graphene composite. As a model molecule, thiourea was utilized to investigate the electrochemical behaviors of the MoO[Formula: see text]H2O-graphene composite modified glass carbon electrode. The results show that the composite modified electrode has higher electron transfer rate than that of graphene modified electrode and bare glass carbon electrode meanwhile the peak currents of it has a good linear relationship with thiourea concentrations in the range of [Formula: see text] ([Formula: see text]) with detection limit of 4.99[Formula: see text][Formula: see text]M ([Formula: see text]). This novel electrochemical sensor exhibits a higher absorption capacity ([Formula: see text][Formula: see text]mol/cm2), a good reproducibility (1.41% relative standard deviation (RSD)), excellent anti-interference and a high stability. These excellent electrochemical properties of the MoO[Formula: see text]H2O-graphene composite are attributed to the loose and porous structure and the synergistic effects between graphene and MoO[Formula: see text]H2O, which make this composite material hold great potential applications for electrochemical sensor.

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Electrochemical Determination of Trace Pb (II) by The Modified Glassy Carbon Electrode Compositing MultiWalled Carbon Nanotubes-Nafion-Bi Film

Journal of Electronics and Sensors ◽

10.31829/2689-6958/jes2020-3(1)-108 ◽

2020 ◽

pp. 1-12

Keyword(s):

Carbon Nanotubes ◽

Glassy Carbon Electrode ◽

Modified Electrode ◽

Glassy Carbon ◽

Anodic Stripping Voltammetry ◽

Electrochemical Sensing ◽

Carbon Electrode ◽

Bismuth Film ◽

Modified Glassy Carbon Electrode

A modified glassy carbon electrode (GCE) compositing multi-walled carbon nanotubes (MWCNTs), Nafion and bismuth film was prepared and applied for the sensitive detection of trace Pb (II). MWCNTs were dispersed into ethanol by ultrasonication in the presence of Nafion and the nanotubes are coated onto the bare GCE. After that, an extra Nafion adhesion agent is added to the electrode. By the in situ plating, a bismuth film was fabricated on the MWCNTs-NA/GCE, making the desired electrode, MWCNTs-NA-Bi/GCE. The modified electrode was characterized by differential pulse anodic stripping voltammetry, scanning electron microscopy, and cyclic voltammetry. A deposition potential of –1.4 V (vs. Ag/AgCl) and a deposition time of 300 s were applied to the working electrode under stirred conditions after optimizing. Nanotubes and Nafion concentrations and pH were carefully optimized to determine trace lead ions by using the electrode as an electrochemical-sensing platform. Nafion effectively increased the stability and adhesivity of the composite film. The MWCNTs-NA-Bi film modified electrode can remarkably increase the anodic peak current of Pb2+. The sensitivity of MWCNTs-NA-Bi/GCE is 4.35 times higher than that of the bare GCE with bismuth film. The prepared electrode showed excellent stability and reproducibility and can be applied for determination of Pb2+ contained wastewater.

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A sensitive electrochemical method for the determination of 5-hydroxytryptophan in rats' brain tissue based on a carbon nanosheets-modified electrode

Analytical Methods ◽

10.1039/c4ay02843k ◽

2015 ◽

Vol 7 (5) ◽

pp. 1971-1976 ◽

Cited By ~ 5

Author(s):

Yahong Chen ◽

Gongke Li ◽

Yufei Hu

Keyword(s):

Brain Tissue ◽

Modified Electrode ◽

Electrochemical Method ◽

Carbon Nanosheets

In this paper, a novel electrochemical method is proposed for the determination of 5-hydroxytryptophan (5-HTP) based on a carbon nanosheets (CNSs)-modified electrode.

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