Limits...
Electrochemical Co-Reduction Synthesis of AuPt Bimetallic Nanoparticles-Graphene Nanocomposites for Selective Detection of Dopamine in the Presence of Ascorbic Acid and Uric Acid.

Zhao Z, Zhang M, Chen X, Li Y, Wang J - Sensors (Basel) (2015)

Bottom Line: In this paper, AuPt bimetallic nanoparticles-graphene nanocomposites were obtained by electrochemical co-reduction of graphene oxide (GO), HAuCl4 and H2PtCl6.The linear range of the constructed DA sensor was from 1.6 μM to 39.7 μM with a detection limit of 0.1 μM (S/N = 3).The obtained DA sensor with good stability, high reproducibility and excellent selectivity made it possible to detect DA in human urine samples.

View Article: PubMed Central - PubMed

Affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China. zhaozongya2010@stu.xjtu.edu.cn.

ABSTRACT
In this paper, AuPt bimetallic nanoparticles-graphene nanocomposites were obtained by electrochemical co-reduction of graphene oxide (GO), HAuCl4 and H2PtCl6. The as-prepared AuPt bimetallic nanoparticles-graphene nanocomposites were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and other electrochemical methods. The morphology and composition of the nanocomposite could be easily controlled by adjusting the HAuCl4/H2PtCl6 concentration ratio. The electrochemical experiments showed that when the concentration ratio of HAuCl4/H2PtCl6 was 1:1, the obtained AuPt bimetallic nanoparticles-graphene nanocomposite (denoted as Au1Pt1NPs-GR) possessed the highest electrocatalytic activity toward dopamine (DA). As such, Au1Pt1NPs-GR nanocomposites were used to detect DA in the presence of ascorbic acid (AA) and uric acid (UA) using the differential pulse voltammetry (DPV) technique and on the modified electrode, there were three separate DPV oxidation peaks with the peak potential separations of 177 mV, 130 mV and 307 mV for DA and AA, DA and UA, AA and UA, respectively. The linear range of the constructed DA sensor was from 1.6 μM to 39.7 μM with a detection limit of 0.1 μM (S/N = 3). The obtained DA sensor with good stability, high reproducibility and excellent selectivity made it possible to detect DA in human urine samples.

Show MeSH

Related in: MedlinePlus

(A) Cyclic voltammetrys of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 0.2 mM dopamine at 30, 50, 80, 100, 150, 200, 250, 300, 350 and 400 mV/s (from a to j); (B) Plots of anodic (Ipa) and cathodic peak currents (Ipc) vs. scan rates.
© Copyright Policy
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4541896&req=5

sensors-15-16614-f006: (A) Cyclic voltammetrys of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 0.2 mM dopamine at 30, 50, 80, 100, 150, 200, 250, 300, 350 and 400 mV/s (from a to j); (B) Plots of anodic (Ipa) and cathodic peak currents (Ipc) vs. scan rates.

Mentions: The effects of scan rate on the electrochemical oxidation at the Au1Pt1NPs-GR/GCE was studied using cyclic voltammetry (CV) techniques in 0.1 M PBS (pH = 7.0) containing 0.2 mM DA with the scan rates varying from 30 mV/s to 400 mV/s. As shown in Figure 6A, as the scan rate increased, the anodic peak potentials (Epa) became more positive whereas the cathodic peak potentials (Epc) became more negative, which indicated that the charge transfer rate slowed and that the reversibility of electrochemical redox reaction of DA became poor. Figure 6B implied that the anodic (Ipa) and cathodic (Ipc) peak currents displayed a linear relationship with the square root of scan rates, and the linear regression equations of Ipa (μA) = −31.013 + 10.993v1/2 (mV/s)1/2 and Ipc (μA) = 25.761 − 9.9627v1/2 (mV/s)1/2 with respective correlation coefficients of R2 = 0.9926 and 0.9964 were obtained, which indicated that the electrochemical oxidation of DA at the obtained electrode was a typical quasi-reversible diffusion-controlled process [39].


Electrochemical Co-Reduction Synthesis of AuPt Bimetallic Nanoparticles-Graphene Nanocomposites for Selective Detection of Dopamine in the Presence of Ascorbic Acid and Uric Acid.

Zhao Z, Zhang M, Chen X, Li Y, Wang J - Sensors (Basel) (2015)

(A) Cyclic voltammetrys of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 0.2 mM dopamine at 30, 50, 80, 100, 150, 200, 250, 300, 350 and 400 mV/s (from a to j); (B) Plots of anodic (Ipa) and cathodic peak currents (Ipc) vs. scan rates.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4541896&req=5

sensors-15-16614-f006: (A) Cyclic voltammetrys of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 0.2 mM dopamine at 30, 50, 80, 100, 150, 200, 250, 300, 350 and 400 mV/s (from a to j); (B) Plots of anodic (Ipa) and cathodic peak currents (Ipc) vs. scan rates.
Mentions: The effects of scan rate on the electrochemical oxidation at the Au1Pt1NPs-GR/GCE was studied using cyclic voltammetry (CV) techniques in 0.1 M PBS (pH = 7.0) containing 0.2 mM DA with the scan rates varying from 30 mV/s to 400 mV/s. As shown in Figure 6A, as the scan rate increased, the anodic peak potentials (Epa) became more positive whereas the cathodic peak potentials (Epc) became more negative, which indicated that the charge transfer rate slowed and that the reversibility of electrochemical redox reaction of DA became poor. Figure 6B implied that the anodic (Ipa) and cathodic (Ipc) peak currents displayed a linear relationship with the square root of scan rates, and the linear regression equations of Ipa (μA) = −31.013 + 10.993v1/2 (mV/s)1/2 and Ipc (μA) = 25.761 − 9.9627v1/2 (mV/s)1/2 with respective correlation coefficients of R2 = 0.9926 and 0.9964 were obtained, which indicated that the electrochemical oxidation of DA at the obtained electrode was a typical quasi-reversible diffusion-controlled process [39].

Bottom Line: In this paper, AuPt bimetallic nanoparticles-graphene nanocomposites were obtained by electrochemical co-reduction of graphene oxide (GO), HAuCl4 and H2PtCl6.The linear range of the constructed DA sensor was from 1.6 μM to 39.7 μM with a detection limit of 0.1 μM (S/N = 3).The obtained DA sensor with good stability, high reproducibility and excellent selectivity made it possible to detect DA in human urine samples.

View Article: PubMed Central - PubMed

Affiliation: The Key Laboratory of Biomedical Information Engineering of Ministry of Education, Institute of Biomedical Engineering, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an 710049, China. zhaozongya2010@stu.xjtu.edu.cn.

ABSTRACT
In this paper, AuPt bimetallic nanoparticles-graphene nanocomposites were obtained by electrochemical co-reduction of graphene oxide (GO), HAuCl4 and H2PtCl6. The as-prepared AuPt bimetallic nanoparticles-graphene nanocomposites were characterized by scanning electron microscopy (SEM), electrochemical impedance spectroscopy (EIS) and other electrochemical methods. The morphology and composition of the nanocomposite could be easily controlled by adjusting the HAuCl4/H2PtCl6 concentration ratio. The electrochemical experiments showed that when the concentration ratio of HAuCl4/H2PtCl6 was 1:1, the obtained AuPt bimetallic nanoparticles-graphene nanocomposite (denoted as Au1Pt1NPs-GR) possessed the highest electrocatalytic activity toward dopamine (DA). As such, Au1Pt1NPs-GR nanocomposites were used to detect DA in the presence of ascorbic acid (AA) and uric acid (UA) using the differential pulse voltammetry (DPV) technique and on the modified electrode, there were three separate DPV oxidation peaks with the peak potential separations of 177 mV, 130 mV and 307 mV for DA and AA, DA and UA, AA and UA, respectively. The linear range of the constructed DA sensor was from 1.6 μM to 39.7 μM with a detection limit of 0.1 μM (S/N = 3). The obtained DA sensor with good stability, high reproducibility and excellent selectivity made it possible to detect DA in human urine samples.

Show MeSH
Related in: MedlinePlus