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 values from a to e: 6.5, 7, 7.5, 8.0, 8.5) containing 0.2 mM DA at scan rate of 100 mV/s; (B) Plots of anodic peak potential (Epa) and anodic peak current (Ipa) vs. pH value.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-16614-f005: (A) Cyclic voltammetrys of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH values from a to e: 6.5, 7, 7.5, 8.0, 8.5) containing 0.2 mM DA at scan rate of 100 mV/s; (B) Plots of anodic peak potential (Epa) and anodic peak current (Ipa) vs. pH value.

Mentions: The above results showed that Au1Pt1NPs-GR/GCE displayed the best electrocatalytic activity toward DA and thus was used to selectively detect DA. In this section, the effects of pH value on DA oxidation at the Au1Pt1NPs-GR/GCE were systematically studied. Figure 5A showed cyclic voltammetric responses of the obtained electrode in 0.1 M PBS (pH values from a to e: 6.5, 7, 7.5, 8.0, 8.5) containing 0.2 mM DA. It was obvious that the anodic peak current (Ipa) reached the maximum value at pH = 7.0, and therefore, pH 7.0 was selected to detect DA in the following experiments. As shown in Figure 5B, anodic peak potential (Epa) linearly decreased as pH changed from 6.5 to 8.0, and the linear regression equation could be expressed as Epa (V) = 0.616 − 0.052 pH (R2 = 0.991). The slope of −52 mV/pH was close to the theoretical value of −59 mV/pH calculated by the Nernst equation, which indicated the same number of electrons and protons involved in DA oxidation reaction at the Au1Pt1NPs-GR/GCE [46].


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 values from a to e: 6.5, 7, 7.5, 8.0, 8.5) containing 0.2 mM DA at scan rate of 100 mV/s; (B) Plots of anodic peak potential (Epa) and anodic peak current (Ipa) vs. pH value.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-16614-f005: (A) Cyclic voltammetrys of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH values from a to e: 6.5, 7, 7.5, 8.0, 8.5) containing 0.2 mM DA at scan rate of 100 mV/s; (B) Plots of anodic peak potential (Epa) and anodic peak current (Ipa) vs. pH value.
Mentions: The above results showed that Au1Pt1NPs-GR/GCE displayed the best electrocatalytic activity toward DA and thus was used to selectively detect DA. In this section, the effects of pH value on DA oxidation at the Au1Pt1NPs-GR/GCE were systematically studied. Figure 5A showed cyclic voltammetric responses of the obtained electrode in 0.1 M PBS (pH values from a to e: 6.5, 7, 7.5, 8.0, 8.5) containing 0.2 mM DA. It was obvious that the anodic peak current (Ipa) reached the maximum value at pH = 7.0, and therefore, pH 7.0 was selected to detect DA in the following experiments. As shown in Figure 5B, anodic peak potential (Epa) linearly decreased as pH changed from 6.5 to 8.0, and the linear regression equation could be expressed as Epa (V) = 0.616 − 0.052 pH (R2 = 0.991). The slope of −52 mV/pH was close to the theoretical value of −59 mV/pH calculated by the Nernst equation, which indicated the same number of electrons and protons involved in DA oxidation reaction at the Au1Pt1NPs-GR/GCE [46].

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