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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.

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Cyclic voltammetrys of bare GCE (a); PtNPs-GR/GCE (b); AuNPs-GR/GCE (c); Au1Pt2NPs-GR/GCE (d); Au2Pt1NPs-GR/GCE (e) and Au1Pt1NPs-GR/GCE (f) in 0.1 M PBS (pH = 7.0) containing 0.2 mM DA. Scan rate: 100 mV/s.
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sensors-15-16614-f004: Cyclic voltammetrys of bare GCE (a); PtNPs-GR/GCE (b); AuNPs-GR/GCE (c); Au1Pt2NPs-GR/GCE (d); Au2Pt1NPs-GR/GCE (e) and Au1Pt1NPs-GR/GCE (f) in 0.1 M PBS (pH = 7.0) containing 0.2 mM DA. Scan rate: 100 mV/s.

Mentions: Figure 4 showed the cyclic voltammetric responses of different electrodes in 0.2 mM DA solution prepared with 0.1 M PBS (pH = 7.0). On bare GCE (curve a), a pair of poor redox peaks with a big peak potential separation of 255 mV appeared. After modified with PtNPs-GR nanocomposite (curve b), the current responses evidently increased, and the potential difference between anodic peak potential and corresponding cathodic peak potential was remarkably reduced to 93 mV, which demonstrated that the synergistic effects of GR and PtNPs could significantly promote electron transfer rates. For AuNPs-GR/GCE (curve c), the redox peak currents further increased. However, the redox current responses of Au1Pt2NPs-GR/GCE (curve d), Au2Pt1NPs-GR/GCE (curve e) and Au1Pt1NPs-GR/GCE (curve f) were obviously bigger than that of PtNPs-GR/GCE and AuNPs-GR/GCE, which indicated that AuPt bimetallic nanoparticles-GR nanocomposites possessed faster electron transfer rates and better electrocatalytic activity toward DA compared with the corresponding monometallic nanoparticles-GR nanocomposites. Of these three bimetallic nanoparticles-GR nanocomposite modified GCE, Au1Pt1NPs-GR/GCE displayed the biggest redox current responses and lowest peak potential difference (only 85 mV), which was consistent with the results of EIS. The above results implied that when the HAuCl4/H2PtCl6 concentration ratio was 1:1 during the preparation of bimetallic nanoparticles-GR nanocomposites, the obtained electrode (Au1Pt1NPs-GR/GCE) showed the best electrocatalytic activity toward DA. Therefore, Au1Pt1NPs-GR/GCE was used to selectively detect DA in the following experiments.


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)

Cyclic voltammetrys of bare GCE (a); PtNPs-GR/GCE (b); AuNPs-GR/GCE (c); Au1Pt2NPs-GR/GCE (d); Au2Pt1NPs-GR/GCE (e) and Au1Pt1NPs-GR/GCE (f) in 0.1 M PBS (pH = 7.0) containing 0.2 mM DA. Scan rate: 100 mV/s.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-16614-f004: Cyclic voltammetrys of bare GCE (a); PtNPs-GR/GCE (b); AuNPs-GR/GCE (c); Au1Pt2NPs-GR/GCE (d); Au2Pt1NPs-GR/GCE (e) and Au1Pt1NPs-GR/GCE (f) in 0.1 M PBS (pH = 7.0) containing 0.2 mM DA. Scan rate: 100 mV/s.
Mentions: Figure 4 showed the cyclic voltammetric responses of different electrodes in 0.2 mM DA solution prepared with 0.1 M PBS (pH = 7.0). On bare GCE (curve a), a pair of poor redox peaks with a big peak potential separation of 255 mV appeared. After modified with PtNPs-GR nanocomposite (curve b), the current responses evidently increased, and the potential difference between anodic peak potential and corresponding cathodic peak potential was remarkably reduced to 93 mV, which demonstrated that the synergistic effects of GR and PtNPs could significantly promote electron transfer rates. For AuNPs-GR/GCE (curve c), the redox peak currents further increased. However, the redox current responses of Au1Pt2NPs-GR/GCE (curve d), Au2Pt1NPs-GR/GCE (curve e) and Au1Pt1NPs-GR/GCE (curve f) were obviously bigger than that of PtNPs-GR/GCE and AuNPs-GR/GCE, which indicated that AuPt bimetallic nanoparticles-GR nanocomposites possessed faster electron transfer rates and better electrocatalytic activity toward DA compared with the corresponding monometallic nanoparticles-GR nanocomposites. Of these three bimetallic nanoparticles-GR nanocomposite modified GCE, Au1Pt1NPs-GR/GCE displayed the biggest redox current responses and lowest peak potential difference (only 85 mV), which was consistent with the results of EIS. The above results implied that when the HAuCl4/H2PtCl6 concentration ratio was 1:1 during the preparation of bimetallic nanoparticles-GR nanocomposites, the obtained electrode (Au1Pt1NPs-GR/GCE) showed the best electrocatalytic activity toward DA. Therefore, Au1Pt1NPs-GR/GCE was used to selectively detect DA in the following experiments.

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