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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).

Show MeSH
Gold particle distribution in the Au -coated carbon fiber as the working electrode in the flow cell after (a) 0 h; (b) 2 h; (c) 5 h; (d) 7 h; (e) 9 h; (f) 12 h.
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f13-sensors-12-03562: Gold particle distribution in the Au -coated carbon fiber as the working electrode in the flow cell after (a) 0 h; (b) 2 h; (c) 5 h; (d) 7 h; (e) 9 h; (f) 12 h.

Mentions: The operational stability of the sensors was studied by continuous exposure to the flow stream. Figure 13 shows the stability of the sensor over 12 h of repetitive injections. The sensor was run with an interval time of 30 min for every injection. The Au/CFE can be used average 12–15 times and after 9 h ceases to perform better than a bare CFE. The presence of a few gold spherical particles was observed on the SEM images over 9 h (Figure 13(e)). This is due the flow assumptions, the dispersion and hydrodynamic effects would predict SEM pattern, i.e., Au particles decrease as the flow time in the flow cell increases at a flow rate 0.5 mL·min−1.


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)

Gold particle distribution in the Au -coated carbon fiber as the working electrode in the flow cell after (a) 0 h; (b) 2 h; (c) 5 h; (d) 7 h; (e) 9 h; (f) 12 h.
© Copyright Policy
Related In: Results  -  Collection

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

f13-sensors-12-03562: Gold particle distribution in the Au -coated carbon fiber as the working electrode in the flow cell after (a) 0 h; (b) 2 h; (c) 5 h; (d) 7 h; (e) 9 h; (f) 12 h.
Mentions: The operational stability of the sensors was studied by continuous exposure to the flow stream. Figure 13 shows the stability of the sensor over 12 h of repetitive injections. The sensor was run with an interval time of 30 min for every injection. The Au/CFE can be used average 12–15 times and after 9 h ceases to perform better than a bare CFE. The presence of a few gold spherical particles was observed on the SEM images over 9 h (Figure 13(e)). This is due the flow assumptions, the dispersion and hydrodynamic effects would predict SEM pattern, i.e., Au particles decrease as the flow time in the flow cell increases at a flow rate 0.5 mL·min−1.

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