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Electrochemical oxidation of cysteine at a film gold modified carbon fiber microelectrode its application in a flow-through voltammetric sensor.

Wang LH, Huang WS - Sensors (Basel) (2012)

Bottom Line: The possible reaction mechanism of the oxidation process is described from the relations to scan rate, peak potentials and currents.For the pulse mode, and measurements with suitable experimental parameters, a linear concentration from 0.5 to 5.0 mg·L(-1) was found.The limit of quantification for cysteine was below 60 ng·mL(-1).

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Chemistry, Chia Nan University of Pharmacy and Science, Tainan, Taiwan. e201466.wang@msa.hinet.net

ABSTRACT
A flow-electrolytical cell containing a strand of micro Au modified carbon fiber electrodes (CFE) has been designedand characterized for use in a voltammatric detector for detecting cysteine using high-performance liquid chromatography. Cysteine is more efficiently electrochemical oxidized on a Au /CFE than a bare gold and carbon fiber electrode. The possible reaction mechanism of the oxidation process is described from the relations to scan rate, peak potentials and currents. For the pulse mode, and measurements with suitable experimental parameters, a linear concentration from 0.5 to 5.0 mg·L(-1) was found. The limit of quantification for cysteine was below 60 ng·mL(-1).

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Scanning electron micrographs (at 4 kV) of a Au-coated carbon fiber composite surface. (a) Au (4 mM) deposits 240 s; (b) Au (4 mM) deposits 360 s; (c) Au (4 mM) deposits 480 s; (d) Au (4 mM) deposits 540 s in 0.1 M acetate buffer (pH 5.02).
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f9-sensors-12-03562: Scanning electron micrographs (at 4 kV) of a Au-coated carbon fiber composite surface. (a) Au (4 mM) deposits 240 s; (b) Au (4 mM) deposits 360 s; (c) Au (4 mM) deposits 480 s; (d) Au (4 mM) deposits 540 s in 0.1 M acetate buffer (pH 5.02).

Mentions: The gold needle-like leaf particles were dispersed with very slight aggregation, as seen in Figure 9(b). A comparision of deposition time and the results are shown in SEM Figure 9(a–d). In Figure 9(c) gold spherical particles were seen and coverage was more uniformly distributed than in the other samples. The particle sizes (Figure 9(a–d)) had diameters of 3.9 μm, 2.5 μm, 0.71 μm and 2.7 μm, respectively. The concentration 4.0 mM of HAuCl4 and 480 s of deposition time were used for coating, because the peak height of cysteine was higher than in the other examples.


Electrochemical oxidation of cysteine at a film gold modified carbon fiber microelectrode its application in a flow-through voltammetric sensor.

Wang LH, Huang WS - Sensors (Basel) (2012)

Scanning electron micrographs (at 4 kV) of a Au-coated carbon fiber composite surface. (a) Au (4 mM) deposits 240 s; (b) Au (4 mM) deposits 360 s; (c) Au (4 mM) deposits 480 s; (d) Au (4 mM) deposits 540 s in 0.1 M acetate buffer (pH 5.02).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376634&req=5

f9-sensors-12-03562: Scanning electron micrographs (at 4 kV) of a Au-coated carbon fiber composite surface. (a) Au (4 mM) deposits 240 s; (b) Au (4 mM) deposits 360 s; (c) Au (4 mM) deposits 480 s; (d) Au (4 mM) deposits 540 s in 0.1 M acetate buffer (pH 5.02).
Mentions: The gold needle-like leaf particles were dispersed with very slight aggregation, as seen in Figure 9(b). A comparision of deposition time and the results are shown in SEM Figure 9(a–d). In Figure 9(c) gold spherical particles were seen and coverage was more uniformly distributed than in the other samples. The particle sizes (Figure 9(a–d)) had diameters of 3.9 μm, 2.5 μm, 0.71 μm and 2.7 μm, respectively. The concentration 4.0 mM of HAuCl4 and 480 s of deposition time were used for coating, because the peak height of cysteine was higher than in the other examples.

Bottom Line: The possible reaction mechanism of the oxidation process is described from the relations to scan rate, peak potentials and currents.For the pulse mode, and measurements with suitable experimental parameters, a linear concentration from 0.5 to 5.0 mg·L(-1) was found.The limit of quantification for cysteine was below 60 ng·mL(-1).

View Article: PubMed Central - PubMed

Affiliation: Department of Medical Chemistry, Chia Nan University of Pharmacy and Science, Tainan, Taiwan. e201466.wang@msa.hinet.net

ABSTRACT
A flow-electrolytical cell containing a strand of micro Au modified carbon fiber electrodes (CFE) has been designedand characterized for use in a voltammatric detector for detecting cysteine using high-performance liquid chromatography. Cysteine is more efficiently electrochemical oxidized on a Au /CFE than a bare gold and carbon fiber electrode. The possible reaction mechanism of the oxidation process is described from the relations to scan rate, peak potentials and currents. For the pulse mode, and measurements with suitable experimental parameters, a linear concentration from 0.5 to 5.0 mg·L(-1) was found. The limit of quantification for cysteine was below 60 ng·mL(-1).

Show MeSH