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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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DPVs of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 50 μM AA, 12 μM UA and different concentrations of DA (from a to k: 1.6, 3, 5, 8, 10, 14, 15.9, 19.9, 23.9, 29.8 and 39.7 μM). Inset: The calibration curve of DA. Scan rate: 10 mV/s, pulse amplitude: 50 mV, pulse width: 40 ms, pulse period: 0.3 s.
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sensors-15-16614-f007: DPVs of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 50 μM AA, 12 μM UA and different concentrations of DA (from a to k: 1.6, 3, 5, 8, 10, 14, 15.9, 19.9, 23.9, 29.8 and 39.7 μM). Inset: The calibration curve of DA. Scan rate: 10 mV/s, pulse amplitude: 50 mV, pulse width: 40 ms, pulse period: 0.3 s.

Mentions: Figure 7 showed the DPV responses of the obtained electrode in 0.1 M PBS (pH = 7.0) containing different concentrations of DA in the presence of 50 μM AA and 12 μM UA at the Au1Pt1NPs-GR/GCE. It could be observed that three peak potentials of AA, DA and UA appeared at −0.07 V, 0.17 V and 0.30 V, respectively. In addition, the potential separations of the DPV oxidation peak were estimated to be 177 mV, 130 mV and 307 mV for DA and AA, DA and UA, and AA and UA, respectively. The separations were large enough to allow the selective detection of DA in the presence of AA and UA. Results implied that the DPV peak currents were proportional to DA concentrations in the range of 1.6–39.7 μM and a linear regression equation of Ipa (μA) = −1.7914 + 1.0806C (μM) (R2 = 0.9943). The limit of detection (LOD) was computed to be 0.1 μM (S/N = 3), based on the following equation where is the standard deviation of five measurements and S is the slope of the calibration line:LOD=3σS


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)

DPVs of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 50 μM AA, 12 μM UA and different concentrations of DA (from a to k: 1.6, 3, 5, 8, 10, 14, 15.9, 19.9, 23.9, 29.8 and 39.7 μM). Inset: The calibration curve of DA. Scan rate: 10 mV/s, pulse amplitude: 50 mV, pulse width: 40 ms, pulse period: 0.3 s.
© Copyright Policy
Related In: Results  -  Collection

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

sensors-15-16614-f007: DPVs of Au1Pt1NPs-GR/GCE in 0.1 M PBS (pH = 7.0) containing 50 μM AA, 12 μM UA and different concentrations of DA (from a to k: 1.6, 3, 5, 8, 10, 14, 15.9, 19.9, 23.9, 29.8 and 39.7 μM). Inset: The calibration curve of DA. Scan rate: 10 mV/s, pulse amplitude: 50 mV, pulse width: 40 ms, pulse period: 0.3 s.
Mentions: Figure 7 showed the DPV responses of the obtained electrode in 0.1 M PBS (pH = 7.0) containing different concentrations of DA in the presence of 50 μM AA and 12 μM UA at the Au1Pt1NPs-GR/GCE. It could be observed that three peak potentials of AA, DA and UA appeared at −0.07 V, 0.17 V and 0.30 V, respectively. In addition, the potential separations of the DPV oxidation peak were estimated to be 177 mV, 130 mV and 307 mV for DA and AA, DA and UA, and AA and UA, respectively. The separations were large enough to allow the selective detection of DA in the presence of AA and UA. Results implied that the DPV peak currents were proportional to DA concentrations in the range of 1.6–39.7 μM and a linear regression equation of Ipa (μA) = −1.7914 + 1.0806C (μM) (R2 = 0.9943). The limit of detection (LOD) was computed to be 0.1 μM (S/N = 3), based on the following equation where is the standard deviation of five measurements and S is the slope of the calibration line:LOD=3σS

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