scholarly journals Reduced Graphene Oxide and Polyaniline Nanofibers Nanocomposite for the Development of an Amperometric Glucose Biosensor

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 948
Author(s):  
Anton Popov ◽  
Ruta Aukstakojyte ◽  
Justina Gaidukevic ◽  
Viktorija Lisyte ◽  
Asta Kausaite-Minkstimiene ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Thermal Reduction ◽  
Glucose Biosensor ◽  
Practical Application ◽  
X Ray Diffraction ◽  
Glucose Determination ◽  
Reduced Graphene ◽  
Graphite Rod

The control of glucose concentration is a crucial factor in clinical diagnosis and the food industry. Electrochemical biosensors based on reduced graphene oxide (rGO) and conducting polymers have a high potential for practical application. A novel thermal reduction protocol of graphene oxide (GO) in the presence of malonic acid was applied for the synthesis of rGO. The rGO was characterized by scanning electron microscopy, X-ray diffraction analysis, Fourier-transform infrared spectroscopy, and Raman spectroscopy. rGO in combination with polyaniline (PANI), Nafion, and glucose oxidase (GOx) was used to develop an amperometric glucose biosensor. A graphite rod (GR) electrode premodified with a dispersion of PANI nanostructures and rGO, Nafion, and GOx was proposed as the working electrode of the biosensor. The optimal ratio of PANI and rGO in the dispersion used as a matrix for GOx immobilization was equal to 1:10. The developed glucose biosensor was characterized by a wide linear range (from 0.5 to 50 mM), low limit of detection (0.089 mM), good selectivity, reproducibility, and stability. Therefore, the developed biosensor is suitable for glucose determination in human serum. The PANI nanostructure and rGO dispersion is a promising material for the construction of electrochemical glucose biosensors.

scholarly journals Magnetization of Ultraviolet-Reduced Graphene Oxide Flakes in Composites Based on Polystyrene

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2519
Author(s):  
Alexander N. Ionov ◽  
Mikhail P. Volkov ◽  
Marianna N. Nikolaeva ◽  
Ruslan Y. Smyslov ◽  
Alexander N. Bugrov
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Reduction Process ◽  
X Ray Diffraction ◽  
Mesoscopic Structure ◽  
Reduced Graphene ◽  
Study Results ◽  
Edge Defects ◽  
Mesoscopic Level ◽  
Ferromagnetic Hysteresis

This work presents our study results of the magnetization of multilayer UV-reduced graphene oxide (UV-rGO), polymer matrix (polystyrene), and a conjugated composite based on them. The mesoscopic structure of the composites synthesized in this work was studied by such methods as X-ray diffraction, SEM, as well as NMR-, IR- and Raman spectroscopy. The magnetization of the composites under investigation and their components was measured using a vibrating-sample magnetometer. It has been shown that the UV-reduction process leads to the formation of many submicron holes distributed inside rGO flakes, which can create edge defects, causing possibly magnetic order in the graphite samples under investigation on the mesoscopic level. This article provides an alternative explanation for the ferromagnetic hysteresis loop in UV-rGO on the base of superconductivity type-II.

scholarly journals Reduced Graphene Oxide Fibre Electrodes for Drug Sensing

Proceedings ◽  
2021 ◽  
Vol 68 (1) ◽  
pp. 18
Author(s):  
Sutthima Sriprasertsuk ◽  
John R. Varcoe ◽  
Carol Crean
Keyword(s):  
Cyclic Voltammetry ◽  
Graphene Oxide ◽  
Carbon Fibre ◽  
Reduced Graphene Oxide ◽  
Limit Of Detection ◽  
Linear Range ◽  
Oxidation Peak ◽  
Reduced Graphene ◽  
Fibre Sensor ◽  
Model Drug

Reduced graphene oxide (rGO) fibre electrodes and their ability to sense paracetamol (as model drug) were studied. rGO was electrodeposited onto carbon fibre by two different approaches: potentiostatic deposition and cyclic voltammetry (CV) in the presence of graphene oxide solution. Carbon fibre electrodes coated with rGO (after five CV cycles) could sense paracetamol with an oxidation peak at 0.62 V (vs. Ag/AgCl). The limit of detection of this fibre sensor was found to be 36.3 µM with a linear range of 50–500 µM of paracetamol (R2 = 0.9901).

Enzymatic glucose biosensor based on bismuth nanoribbons electrochemically deposited on reduced graphene oxide

2015 ◽  
Vol 182 (13-14) ◽  
pp. 2165-2172 ◽  
Author(s):  
Rajkumar Devasenathipathy ◽  
Raj Karthik ◽  
Shen-Ming Chen ◽  
Mohammad Ajmal Ali ◽  
Veerappan Mani ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Glucose Biosensor ◽  
Reduced Graphene ◽  
Electrochemically Deposited

Thermal reduction to control the spacing in graphene oxide membranes: effect on ion diffusion and electrical conduction

RSC Advances ◽  
2016 ◽  
Vol 6 (74) ◽  
pp. 70012-70017 ◽  
Author(s):  
A. Alhadhrami ◽  
S. Salgado ◽  
V. Maheshwari
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Electrical Conduction ◽  
Thermal Reduction ◽  
Electrochemical Characteristics ◽  
Ion Diffusion ◽  
Layer Spacing ◽  
Reduced Graphene ◽  
Oxide Membranes ◽  
Graphene Oxide Membranes

Inter-layer spacing in reduced graphene-oxide membranes which modulates their ion-diffusion electrical and electrochemical characteristics is controlled by temperature of thermal reduction.

A composite of CoNiP quantum dots decorating reduced graphene oxide as a sulfur host for Li-S batteries

2021 ◽  
Author(s):  
Tingjiao Xiao ◽  
Fengjin Yi ◽  
Mingzhi Yang ◽  
Weiliang Liu ◽  
Mei Li ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Rate Capability ◽  
Cycling Performance ◽  
Practical Application ◽  
Shuttle Effect ◽  
Reduced Graphene ◽  
Sulfur Host ◽  
Kinetics Of

The “shuttle effect” and sluggish reaction kinetics of lithium polysulfides lead to inferior cycling performance and rate capability of Li-S batteries, which hurdles their practical application. Herein, a composite of...

scholarly journals Electrodeposition–Assisted Assembled Multilayer Films of Gold Nanoparticles and Glucose Oxidase onto Polypyrrole-Reduced Graphene Oxide Matrix and Their Electrocatalytic Activity toward Glucose

Nanomaterials ◽  
2018 ◽  
Vol 8 (12) ◽  
pp. 993 ◽  
Author(s):  
Baoyan Wu ◽  
Shihua Hou ◽  
Yongyong Xue ◽  
Zhan Chen
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Glucose Oxidase ◽  
Reduced Graphene Oxide ◽  
Self Assembly ◽  
Electrocatalytic Activity ◽  
Multilayer Films ◽  
Glucose Biosensor ◽  
Future Design ◽  
Reduced Graphene

The study reports a facile and eco-friendly approach for nanomaterial synthesis and enzyme immobilization. A corresponding glucose biosensor was fabricated by immobilizing the gold nanoparticles (AuNPs) and glucose oxidase (GOD) multilayer films onto the polypyrrole (PPy)/reduced graphene oxide (RGO) modified glassy carbon electrode (GCE) via the electrodeposition and self-assembly. PPy and graphene oxide were first coated on the surface of a bare GCE by the electrodeposition. Then, AuNPs and GOD were alternately immobilized onto PPy-RGO/GCE electrode using the electrodeposition of AuNPs and self-assembly of GOD to obtain AuNPs-GOD multilayer films. The resulting PPy-RGO-(AuNPs-GOD)n/GCE biosensors were used to characterize and assess their electrocatalytic activity toward glucose using cyclic voltammetry and amperometry. The response current increased with the increased number of AuNPs-GOD layers, and the biosensor based on four layers of AuNPs-GOD showed the best performance. The PPy-RGO-(AuNPs-GOD)4/GCE electrode can detect glucose in a linear range from 0.2 mM to 8 mM with a good sensitivity of 0.89 μA/mM, and a detection limit of 5.6 μM (S/N = 3). This study presents a promising eco-friendly biosensor platform with advantages of electrodeposition and self-assembly, and would be helpful for the future design of more complex electrochemical detection systems.

scholarly journals Poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic frameworks as a high-performance symmetrical supercapacitor device

2021 ◽  
Author(s):  
Dharshini Mohanadas ◽  
Muhammad Amirul Aizat Mohd Abdah ◽  
Nur Hawa Nabilah Azman ◽  
Thahira B.S.A. Ravoof ◽  
Yusran Sulaiman
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
High Performance ◽  
Metal Organic Framework ◽  
Specific Power ◽  
X Ray Diffraction ◽  
Reduced Graphene ◽  
Metal Organic ◽  
Energy Storage Material ◽  
Organic Framework

Abstract A novel poly(3,4-ethylenedioxythiophene)-reduced graphene oxide/copper-based metal-organic framework (PrGO/HKUST-1) has been successfully fabricated by incorporating electrochemically synthesized poly(3,4-ethylenedioxythiophene)-reduced graphene oxide (PrGO) and hydrothermally synthesized copper-based metal-organic framework (HKUST-1). The field emission scanning microscopy (FESEM) and elemental mapping analysis revealed an even distribution of poly(3,4-ethylenedioxythiophene) (PEDOT), reduced graphene oxide (rGO) and HKUST-1. The crystalline structure and vibration modes of PrGO/HKUST-1 was validated utilizing X-ray diffraction (XRD) as well as Raman spectroscopy, respectively. A remarkable specific capacitance (360.5 F/g) was obtained for PrGO/HKUST-1 compared to HKUST-1 (103.1 F/g), PrGO (98.5 F/g) and PEDOT (50.8 F/g) using KCl/PVA as a gel electrolyte. Moreover, PrGO/HKUST-1 composite with the longest charge/discharge time displayed excellent specific energy (21.0 Wh/kg), specific power (479.7 W/kg) and outstanding cycle life (95.5%) over 4000 cycles. Thus, the PrGO/HKUST-1 can be recognized as a promising energy storage material.

Reduced Graphene Oxide Paper: Fabrication by a Green Thermal Reduction Method and Preliminary Study of its In Vitro Cytotoxicity

2017 ◽  
Vol 45 ◽  
pp. 199-207 ◽  
Author(s):  
Xin Wang ◽  
Peng Li ◽  
Claudia Luedecke ◽  
Qiang Zhang ◽  
Zan Wang ◽  
...  
Keyword(s):  
Tissue Engineering ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Mammalian Cells ◽  
Reduction Method ◽  
Heating Temperature ◽  
Synthesis Method ◽  
Thermal Reduction ◽  
Graphene Films ◽  
Reduced Graphene

Graphene films have been intensively explored because of their unique mechanical and physicochemical properties for potential applications in field of tissue engineering and implants. However, for biomedical applications, it is necessary to fully understand the toxicity and biocompatibility of the prepared graphene films since different synthesis method might lead to different biological properties. Here we report a step-by-step thermal reduction method of preparing reduced graphene oxide (rGO) film directly on various substrates at low heating temperature (below about 200 °C) without requiring any chemical reduction agent like hydrazine or other reductants (therefore we call it green method). Slowly heating GO hydrosol that was coated on the surface of a glass cell-culture dish or inside of a polypropylene tube from room temperature to 60, 100, and 160 °C for 12 h, respectively, a shiny and flat surface without crumpled structure or tiny pores was formed. We peeled it off from the substrate to explore its cytotoxicity. The results exhibited that the rGO film was biocompatible with Cal-72 cell but against Escherichia coli bacteria. Our work confirmed that rGO film produced by the green reduction method is cytocompatible with mammalian cells, which makes this rGO film a promising material for tissue engineering scaffold or as a surface-modification coating of an implant.

scholarly journals Reduced Graphene Oxide–Epoxy Grafted Poly(Styrene-Co-Acrylate) Composites for Corrosion Protection of Mild Steel

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 666
Author(s):  
Xinchuan Fan ◽  
Yue Hu ◽  
Yijun Zhang ◽  
Jiachen Lu ◽  
Xiaofeng Chen ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
X Ray ◽  
Transmission Electron ◽  
Reduced Graphene ◽  
Scanning Electron

Reduced graphene oxide–epoxy grafted poly(styrene-co-acrylate) composites (GESA) were prepared by anchoring different amount of epoxy modified poly(styrene-co-acrylate) (EPSA) onto reduced graphene oxide (rGO) sheets through π–π electrostatic attraction. The GESA composites were characterized by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The anti-corrosion properties of rGO/EPSA composites were evaluated by electro-chemical impedance spectroscopy (EIS) in hydroxyl-polyacrylate coating, and the results revealed that the corrosion rate was decreased from 3.509 × 10−1 to 1.394 × 10−6 mm/a.

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