scholarly journals Electrochemical Sensor for Rapid and Sensitive Detection of Tryptophan by a Cu2O Nanoparticles-Coated Reduced Graphene Oxide Nanocomposite

Biomolecules ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 176 ◽  
Author(s):  
Quanguo He ◽  
Yaling Tian ◽  
Yiyong Wu ◽  
Jun Liu ◽  
Guangli Li ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Low Cost ◽  
Supporting Electrolyte ◽  
Modified Electrodes ◽  
High Sensitivity ◽  
Experimental Conditions ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide

In this paper, a nanocomposite of cuprous oxide and electrochemically reduced graphene oxide (Cu2O–ERGO) was prepared by a simple and low-cost method; hereby, a new method for the electrochemical determination of tryptophan (Trp) by this composite modified glassy carbon electrode (GCE) is proposed. The prepared materials and modified electrodes were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and cyclic voltammetry (CV). The results showed that Cu2O–ERGO/GCE had good electrocatalytic activity for Trp. The effects of supporting electrolyte, scanning rate, accumulation potential, and accumulation time on the determination of Trp were studied. Under the optimum experimental conditions, Trp was quantitatively analyzed by square-wave voltammetry (SWV). The oxidation peak current of Trp had a good linear relationship with its concentration in the range of 0.02–20 μM, and the detection limit was 0.01 μM (S/N = 3). In addition, the modified electrode has high sensitivity, good repeatability, and long-term stability. Finally, the proposed method has been successfully applied in the determination of Trp concentration in practical samples.

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.

A one-step electrochemically reduced graphene oxide based sensor for sensitive voltammetric determination of furfural in milk products

2021 ◽  
Vol 13 (1) ◽  
pp. 56-63
Author(s):  
Qiuqiu Wang ◽  
Juanhua Zhang ◽  
Yanbo Xu ◽  
Yingyi Wang ◽  
Liang Wu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Surface ◽  
High Surface Area ◽  
Milk Products ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
One Step ◽  
Dairy Milk

One-step electrochemically reduced graphene oxide with high surface area and improved electron transfer kinetics shows great performances in the determination of furfural in dairy milk.

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.

Tuning the direct growth of Agseeds into bimetallic Ag@Cu nanorods on surface functionalized electrochemically reduced graphene oxide: enhanced nitrite detection

RSC Advances ◽  
2015 ◽  
Vol 5 (60) ◽  
pp. 48236-48245 ◽  
Author(s):  
S. E. Jeena ◽  
P. Gnanaprakasam ◽  
Arun Dakshinamurthy ◽  
T. Selvaraju
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Sensitivity ◽  
Oxide Surface ◽  
Nitrite Ion ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
Direct Growth ◽  
1D Nanostructure ◽  
Good Detection Limit

The significant challenges in the growth of 1D nanostructure on reduced graphene oxide surface were addressed. It enabled the electrooxidation of the nitrite ion (NO2−) with high sensitivity and good detection limit of 1 nM.

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