scholarly journals Simultaneous detection of ascorbic acid, dopamine, uric acid and tryptophan with Azure A-interlinked multi-walled carbon nanotube/gold nanoparticles composite modified electrode

2016 ◽  
Vol 9 (3) ◽  
pp. 471-480 ◽  
Author(s):  
Hayati Filik ◽  
Asiye Aslıhan Avan ◽  
Sevda Aydar
2015 ◽  
Vol 7 (4) ◽  
pp. 1471-1477 ◽  
Author(s):  
Siyuan Wang ◽  
Wen Zhang ◽  
Xia Zhong ◽  
Yaqin Chai ◽  
Ruo Yuan

A nanohybrid (RGO–PAMAM–MWCNT–AuNPs) for simultaneous electrochemical determination of ascorbic acid (AA), dopamine (DA) and uric acid (UA) was reported in this paper.


Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4427
Author(s):  
Daria Minta ◽  
Zoraida González ◽  
Piotr Wiench ◽  
Stanisław Gryglewicz ◽  
Grażyna Gryglewicz

Gold nanoparticles (AuNPs) were homogeneously electrodeposited on nitrogen-doped reduced graphene oxide (N-rGO) to modify a glassy carbon electrode (GCE/N-rGO-Au) in order to improve the simultaneous detection of dopamine (DA), ascorbic acid (AA), and uric acid (UA). N-rGO was prepared by the hydrothermal treatment of graphene oxide (GO) and urea at 180 °C for 12 h. AuNPs were subsequently electrodeposited onto the surface of GCE/N-rGO using 1 mM HAuCl4 solution. The morphology and chemical composition of the synthesized materials were characterized by field-emission scanning electron microscopy and X-ray photoelectron spectroscopy. The electrochemical performance of the modified electrodes was investigated through cyclic voltammetry and differential pulse voltammetry measurements. Compared to GCE/rGO-Au, GCE/N-rGO-Au exhibited better electrochemical performance towards the simultaneous detection of the three analytes due to the more homogeneous distribution of the metallic nanoparticles as a result of more efficient anchoring on the N-doped areas of the graphene structure. The GCE/N-rGO-Au-based sensor operated in a wide linear range of DA (3–100 µM), AA (550–1500 µM), and UA (20–1000 µM) concentrations with a detection limit of 2.4, 58, and 8.7 µM, respectively, and exhibited satisfactory peak potential separation values of 0.34 V (AA-DA), 0.20 V, (DA-UA) and 0.54 V (AA-UA). Remarkably, GCE/N-rGO-Au showed a very low detection limit of 385 nM towards DA, not being susceptible to interference, and maintained 90% of its initial electrochemical signal after one month, indicating an excellent long-term stability.


2004 ◽  
Vol 20 (7) ◽  
pp. 1055-1059 ◽  
Author(s):  
Lingyan JIANG ◽  
Chuanyin LIU ◽  
Liping JIANG ◽  
Zhen PENG ◽  
Guanghan LU

2021 ◽  
Vol 83 (3) ◽  
pp. 85-92
Author(s):  
Azleen Rashidah Mohd Rosli ◽  
Farhanini Yusoff ◽  
Saw Hong Loh ◽  
Hanis Mohd Yusoff ◽  
Muhammad Mahadi Abdul Jamil ◽  
...  

A magnetic nanoparticles/reduced graphene oxide modified glassy carbon electrode (MNP/rGO/GCE) was fabricated via one-step facile synthesis route for the simultaneous determination of ascorbic acid (AA), dopamine (DA), along with uric acid (UA). A series of diseases and disorders has been associated with irregular levels of these respective analytes, thus early detection is highly crucial. Physical and electrochemical characterization of the modified electrode was conducted by using Scanning Electron Microscopy (SEM), Fourier Transform Infrared (FTIR) analysis, X-Ray Diffraction (XRD) analysis and Brauneur-Emmet-Teller (BET), Cyclic Voltammetry (CV) and Electron Impedance Spectroscopy (EIS). The results obtained confirmed the formation of MNP/rGO composite. Differential pulse voltammetry (DPV) of MNP/rGO/GCE displays three well-defined peaks which associated to AA, DA and UA, respectively. The response towards DA is linear in the concentration range of 15 nM to 100 µM with a detection limit of 0.19 nM while a response to AA and UA is also linear in the concentration range of 10 µM to 100 µM with a limit of detection 0.22 µM and 45 nM respectively. The proposed modified electrode offers a good response towards simultaneous detection of three different electroactive species with excellent electron transfer rate, great capacitance and ideal diffusive control behavior.


Micromachines ◽  
2020 ◽  
Vol 11 (3) ◽  
pp. 294 ◽  
Author(s):  
Shuting Wang ◽  
Celia Ferrag ◽  
Meissam Noroozifar ◽  
Kagan Kerman

In this study, we developed a modified glassy carbon electrode (GCE) with graphene oxide, multi-walled carbon nanotube hybrid nanocomposite in chitosan (GCE/GO-MWCNT-CHT) to achieve simultaneous detection of four nucleobases (i.e., guanine (G), adenine (A), thymine (T) and cytosine (C)) along with uric acid (UA) as an internal standard. The nanocomposite was characterized using TEM and FT-IR. The linearity ranges were up to 151.0, 78.0, 79.5, 227.5, and 162.5 µM with a detection limit of 0.15, 0.12, 0.44, 4.02, 4.0, and 3.30 µM for UA, G, A, T, and C, respectively. Compared to a bare GCE, the nanocomposite-modified GCE demonstrated a large enhancement (~36.6%) of the electrochemical active surface area. Through chronoamperometric studies, the diffusion coefficients (D), standard catalytic rate constant (Ks), and heterogenous rate constant (Kh) were calculated for the analytes. Moreover, the nanocomposite-modified electrode was used for simultaneous detection in human serum, human saliva, and artificial saliva samples with recovery values ranging from 95% to 105%.


Sign in / Sign up

Export Citation Format

Share Document