Decoration of Plasma-Reduced Graphene Oxide with Uniform Gold Nanoparticles and their Redox Reaction Performance

2016 ◽  
Vol 701 ◽  
pp. 47-51
Author(s):  
Khairul Anuar Wahid ◽  
M.A.S.M. Haniff ◽  
M. Ismahadi ◽  
Ishak Abdul Azid
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Effective Area ◽  
Au Nps ◽  
Sensor Platform ◽  
Reduced Graphene ◽  
Reaction Performance ◽  
Average Size ◽  
Defective Sites

This paper reports a method to enhance the electro-activity on screen printing carbon electrode (SPCE) for electrochemical sensor platform application. The method to forming uniform gold nanoparticles on reduced graphene oxide and SPCE (Au-Nps/rGO/SPCE) based on plasma-enhanced CVD process has been investigated. The results demonstrated that the Au-NPs with high density and uniform sizes were successfully introduced via CVD process where the average size and thickness are 15.9+10nm and 2.18+0.4nm respectively. A high ID/IG ratio for Au-NPs/rGO is 1.01 which 44% higher compared to GO ID/IG ratio was observed in the Raman spectrum suggesting more defective sites on the surface of Au NPS/rGO. The redox performance of Au-NPs/rGO/SPCE has also been measured and compared with rGO/SPCE and the results shown that rGO decorated with Au-NPs has a highest redox current. The peak currents of Au-NPs/rGO are significantly increased compared to the bare SPCE with increment from 0.05mA to 0.14mA. This result is proportional with the effective surface area for SPCE that has been decorated with Au-NPs/rGO where the effective area is increased from 0.126cm2 to 0.166cm2. The peak potential at 0.01V which was found to shift up to 0.4V as the scan rate increases suggested that reaction is electrochemically reversible.

scholarly journals Label-Free and Highly-Sensitive Detection of Ochratoxin A Using One-Pot Synthesized Reduced Graphene Oxide/Gold Nanoparticles-Based Impedimetric Aptasensor

Biosensors ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 87
Author(s):  
Yasmin Alhamoud ◽  
Yingying Li ◽  
Haibo Zhou ◽  
Ragwa Al-Wazer ◽  
Yiying Gong ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Ochratoxin A ◽  
Fetal Malformation ◽  
Label Free ◽  
One Pot ◽  
Au Nps ◽  
Reduced Graphene ◽  
Relative Standard

Ochratoxin A (OTA) primarily obtained by the genera aspergillus and penicillium, is one of the toxic substances for different organs and systems of the human body such as the kidney, liver, neurons and the immune system. Moreover, it is considered to cause tumors and fetal malformation even at a very low concentration. Fast and sensitive assay for detection of OTA at ultralow levels in foods and agricultural products has been an increasing demand. In this study, a new label-free electrochemical biosensor based on three-dimensional reduced graphene oxide/gold nanoparticles/aptamer for OTA detection was constructed. The 3D-rGO/Au NPs nanocomposites were firstly synthesized using a one-pot hydrothermal process under optimized experimental conditions. The 3D-rGO/Au NPs with considerable particular surface area and outstanding electrical conductivity was then coated on a glass carbon electrode to provide tremendous binding sites for -SH modified aptamer via the distinctive Au–S linkage. The presence of OTA was specifically captured by aptamer and resulted in electrochemical impedance spectroscopy (EIS) signal response accordingly. The constructed impedimetric aptasensor obtained a broad linear response from 1 pg/mL to 10 ng/mL with an LOD of 0.34 pg/mL toward OTA detection, highlighting the excellent sensitivity. Satisfactory reproducibility was also achieved with the relative standard deviation (RSD) of 1.393%. Moreover, the proposed aptasensor obtained a good recovery of OTA detection in red wine samples within the range of 93.14 to 112.75% along with a low LOD of 0.023 ng/mL, indicating its applicability for OTA detection in real samples along with economical, specific, susceptible, fast, easy, and transportable merits.

scholarly journals Uniform Decoration of Reduced Graphene Oxide Sheets with Gold Nanoparticles

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Huanping Yang ◽  
Weiwei Zhou ◽  
Bo Yu ◽  
Yingying Wang ◽  
Chunxiao Cong ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Ionic Liquid ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Surface Enhanced Raman Spectroscopy ◽  
Simple Method ◽  
Au Nps ◽  
Reduced Graphene ◽  
Modified Graphene Oxide ◽  
Graphene Oxide Sheets

A simple method employing ionic liquid functionalization is developed to achieve the uniform decoration of reduced graphene oxide sheets with gold nanoparticles. The synthesis of ionic liquid modified graphene oxide is accomplished by covalently binding 1-(3-Aminopropyl) imidazole with GO sheets. The formation mechanism of Au nanoparticles on RGO sheets is proposed to loadAuCl4-onto the surface of GO sheets through anion exchange; then reduceAuCl4-to Au NPs and at the same time reduce GO sheets to RGO sheets via a one-step process. The presence of Au NPs is well identified by SEM, TEM, and XPS. As a concept, the RGO-supported Au NPs is applied to surface-enhanced Raman spectroscopy.

Hg(II) Ion Detection Using Thermally Reduced Graphene Oxide Decorated with Functionalized Gold Nanoparticles

2012 ◽  
Vol 84 (9) ◽  
pp. 4057-4062 ◽  
Author(s):  
Kehung Chen ◽  
Ganhua Lu ◽  
Jingbo Chang ◽  
Shun Mao ◽  
Kehan Yu ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Ion Detection ◽  
Functionalized Gold Nanoparticles ◽  
Reduced Graphene

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.

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