Electrochemical sensing of nitrofurazone on Ru(bpy)32+ functionalized polyoxometalate combined with graphene modified electrode

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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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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