scholarly journals A sensitive electrochemical sensor based on polypyrrole/electrochemically reduced graphene oxide for the determination of imidacloprid

2019 ◽  
Vol 9 (3) ◽  
pp. 143-152 ◽  
Author(s):  
Chenglong Chen ◽  
Zhen Han ◽  
Wu Lei ◽  
Yong Ding ◽  
Jingjing Lv ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electrochemical Sensor ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Ph Value ◽  
Differential Pulse ◽  
Reduction Peak ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
Sample Testing

The glassy carbon electrode (GCE) was modified by electrochemically reduced graphene oxide (ERGO) and polypyrrole (PPy) prepared by simple cyclic voltammetry (CV) electropoly­merization. The PPy/ERGO modified electrode (PPy/ERGO/GCE) was used as a platform of electrochemical sensor to detect imidacloprid (IMI) insecticide. CV and differential pulse voltammetry (DPV) were chosen as the methods to investigate of the electrochemical behavior of IMI on PPy/ERGO/GCE surface. Scanning electron microscopy (SEM) and Raman spectra were utilized to describe the morphology and structure of the modified electrode. Experimental parameters were optimized, such as the number of polymerization cycles, scan rate and the pH value of electrolyte. Under the optimized conditions, when the concentration of IMI was in the range of 1-10 μM and 10-60 μM, the increase of reduction peak current was linear with the concentration of IMI, and the low detection limit was found to be 0.18 μM (S/N = 3). Results showed that PPy/ERGO/GCE demonstrated satisfactory reproducibility and stability, and has great potential in actual sample testing.

scholarly journals Facile Electrochemical Sensor for Nanomolar Rutin Detection Based on Magnetite Nanoparticles and Reduced Graphene Oxide Decorated Electrode

Nanomaterials ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 115 ◽  
Author(s):  
Quanguo He ◽  
Yiyong Wu ◽  
Yaling Tian ◽  
Guangli Li ◽  
Jun Liu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Electron Microscope ◽  
Electrochemical Sensor ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Simple Method ◽  
Detection Range ◽  
Fe3o4 Nps ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

A new electrochemical sensor for nanomolar rutin detection based on amine-functionalized Fe3O4 nanoparticles and electrochemically reduced graphene oxide nanocomposite modified glassy carbon electrode (NH2-Fe3O4 NPs-ErGO/GCE) was fabricated through a simple method, and the X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), transmission electron microscope (TEM), vibrating sample magnetometer (VSM) and electrochemical technique were used to characterize the modified electrode. The electrochemical behavior of rutin on the Fe3O4 NPs-ErGO/GCE was studied in detail. The electrochemical response of rutin at this modified electrode was remarkably higher than that of the bare GCE or other modified GCE (GO/GCE, Fe3O4 NPs-GO/GCE, and ErGO/GCE). Under the optimum determination conditions, Fe3O4 NPs-ErGO/GCE provided rutin with a broader detection range of 6.0 nM–0.1 µM; 0.1–8.0 µM and 8.0–80 µM, a minimum detectable concentration of 4.0 nM was obtained after 210 s accumulation. This novel method was applied in determination of rutin in pharmaceutical tablets and urine samples with satisfactory results.

scholarly journals Simultaneous Voltammetric Determination of Ascorbic Acid, Paracetamol, and Caffeine Using Electrochemically Reduced Graphene-Oxide-Modified Electrode

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Nguyen Hai Phong ◽  
Tran Thanh Tam Toan ◽  
Mai Xuan Tinh ◽  
Tran Ngoc Tuyen ◽  
Tran Xuan Mau ◽  
...  
Keyword(s):  
Ascorbic Acid ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Anodic Stripping Voltammetry ◽  
Pharmaceutical Preparations ◽  
Differential Pulse ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

In the present paper, graphene oxide was directly electrodeposited by means of cyclic voltammetric techniques on the glassy-carbon electrode (GCE) to obtain a reduced graphene-oxide-modified electrode (ErGO/GCE). Cyclic voltammetry (CV) and differential pulse anodic stripping voltammetry (DP-ASV) had been utilized to study the electrochemical behavior of ErGO/GCE toward ascorbic acid (AA), paracetamol (PA), and caffeine (CA). Differential pulse voltammetry results show that AA, PA, and CA could be detected selectively and sensitively on ErGO/GCE with peak-to-peak separation of 312 mV and 756 mV for AA–PA and PA–CA, respectively. The factors affecting the voltammetric signals such as pH, scan rate, and interferents were addressed. The results reveal that the ErGO/GCE-modified electrode exhibits excellent electrochemical activity in the oxidation of PA, CA, and AA. The detection limits are 0.36 μM, 0.25 μM, and 0.23 μM for AA, PA and CA, respectively, suggesting that the ErGO/GCE can be utilized with high sensitivity and selectivity for the simultaneous determination of these compounds. Finally, the proposed method was successfully used to determine AA, PA, and CA in pharmaceutical preparations.

scholarly journals Simultaneous Determination of Uric Acid and Xanthine Using a Poly(Methylene Blue) and Electrochemically Reduced Graphene Oxide Composite Film Modified Electrode

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Gen Liu ◽  
Wei Ma ◽  
Yan Luo ◽  
Deng-ming Sun ◽  
Shuang Shao
Keyword(s):  
Methylene Blue ◽  
Uric Acid ◽  
Graphene Oxide ◽  
Composite Film ◽  
Simultaneous Determination ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

Poly(methylene blue) and electrochemically reduced graphene oxide composite film modified electrode (PMB-ERGO/GCE) was successfully fabricated by electropolymerization and was used for simultaneous determination of uric acid (UA) and xanthine (Xa). Based on the excellent electrocatalytic activity of PMB-ERGO/GCE, the electrochemical behaviors of UA and Xa were studied by cyclic voltammetry (CV) and square wave voltammetry (SWV). Two anodic sensitive peaks at 0.630 V (versus Ag/AgCl) for UA and 1.006 V (versus Ag/AgCl) for Xa were given by CV in pH 3.0 phosphate buffer. The calibration curves for UA and Xa were obtained in the range of 8.00 × 10−8~4.00 × 10−4 M and 1.00 × 10−7~4.00 × 10−4 M, respectively, by SWV. The detection limits for UA and Xa were3.00×10-8 M and5.00×10-8 M, respectively. Finally, the proposed method was applied to simultaneously determine UA and Xa in human urine with good selectivity and high sensitivity.

Highly sensitive biosensing of phenol based on the adsorption of the phenol enzymatic oxidation product on the surface of an electrochemically reduced graphene oxide-modified electrode

2018 ◽  
Vol 10 (23) ◽  
pp. 2731-2739 ◽  
Author(s):  
Amir Kaffash ◽  
Hamid R. Zare ◽  
Khosrow Rostami
Keyword(s):  
Graphene Oxide ◽  
Horseradish Peroxidase ◽  
Reduced Graphene Oxide ◽  
Modified Electrode ◽  
Enzymatic Oxidation ◽  
Reduced Graphene ◽  
Highly Sensitive ◽  
Electrochemically Reduced Graphene Oxide ◽  
Phenol Determination ◽  
Peroxidase Enzyme

An electrochemically reduced graphene oxide and horseradish peroxidase enzyme modified electrode has been used for phenol determination.

scholarly journals A label-free biosensor based on graphene and reduced graphene oxide dual-layer for electrochemical determination of beta-amyloid biomarkers

2020 ◽  
Vol 187 (5) ◽  
Author(s):  
Jagriti Sethi ◽  
Michiel Van Bulck ◽  
Ahmed Suhail ◽  
Mina Safarzadeh ◽  
Ana Perez-Castillo ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Electrochemical Techniques ◽  
Differential Pulse ◽  
Electrochemical Determination ◽  
Label Free ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

AbstractA label-free biosensor is developed for the determination of plasma-based Aβ1–42 biomarker in Alzheimer’s disease (AD). The platform is based on highly conductive dual-layer of graphene and electrochemically reduced graphene oxide (rGO). The modification of dual-layer with 1-pyrenebutyric acid N-hydroxysuccinimide ester (Pyr-NHS) is achieved to facilitate immobilization of H31L21 antibody. The effect of these modifications were studied with morphological, spectral and electrochemical techniques. The response of the biosensor was evaluated using differential pulse voltammetry (DPV). The data was acquired at a working potential of ~ 180 mV and a scan rate of 50 mV s−1. A low limit of detection (LOD) of 2.398 pM is achieved over a wide linear range from 11 pM to 55 nM. The biosensor exhibits excellent specificity over Aβ1–40 and ApoE ε4 interfering species. Thus, it provides a viable tool for electrochemical determination of Aβ1–42. Spiked human and mice plasmas were used for the successful validation of the sensing platform in bio-fluidic samples. The results obtained from mice plasma analysis concurred with the immunohistochemistry (IHC) and magnetic resonance imaging (MRI) data obtained from brain analysis.

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