Document Detail

Simultaneous voltammetric measurement of ascorbic acid, epinephrine and uric acid at a glassy carbon electrode modified with caffeic acid.
MedLine Citation:
PMID:  15871920     Owner:  NLM     Status:  MEDLINE    
A stable electroactive thin film of poly(caffeic acid) has been deposited on the surface of a glassy carbon electrode by potentiostatic technique in an aqueous solution containing caffeic acid. Poly(caffeic acid) was used as a modified electrode for the detection of ascorbic acid (AA), epinephrine (EP), uric acid (UA) and their mixture by cyclic voltammetry. This modified electrode exhibits potent and persistent electron-mediating behavior followed by well-separated oxidation peaks towards AA, EP and UA with activation overpotential. For the ternary mixture containing AA, EP and UA, the three compounds can well separate from each other at the scan rate of 20 mVs(-1) with a potential difference of 156, 132 and 288 mV between AA and EP, EP and UA and AA and UA, respectively, which was large enough to determine AA, EP and UA individually and simultaneously. The catalytic peak current obtained, was linearly dependent on the AA, EP and UA concentrations in the range of 2.0 x 10(-5) to 1.0 x 10(-3) mol l(-1), 2.0 x 10(-6) to 8.0 x 10(-5) mol l(-1) and 5.0 x 10(-6) to 3.0 x 10(-4) mol l(-1), and the detection limits for AA, EP and UA were 7.0 x 10(-6), 2.0 x 10(-7) and 6.0 x 10(-7) mol l(-1), respectively. The modified electrode shows good sensitivity, selectivity and stability, and has been applied to the determination of EP in practical injection samples and that of EP, UA and AA simultaneously with satisfactory results.
Wang Ren; Hong Qun Luo; Nian Bing Li
Publication Detail:
Type:  Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Biosensors & bioelectronics     Volume:  21     ISSN:  0956-5663     ISO Abbreviation:  Biosens Bioelectron     Publication Date:  2006 Jan 
Date Detail:
Created Date:  2005-12-21     Completed Date:  2006-03-17     Revised Date:  2009-07-14    
Medline Journal Info:
Nlm Unique ID:  9001289     Medline TA:  Biosens Bioelectron     Country:  England    
Other Details:
Languages:  eng     Pagination:  1086-92     Citation Subset:  IM    
School of Chemistry and Chemical Engineering, Southwest China Normal University, Chongqing 400715, China.
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MeSH Terms
Ascorbic Acid / analysis*
Biosensing Techniques / instrumentation,  methods*
Caffeic Acids / chemistry*
Carbon / chemistry
Coated Materials, Biocompatible / chemistry*
Complex Mixtures / analysis
Electrochemistry / instrumentation,  methods*
Epinephrine / analysis*
Glass / chemistry
Uric Acid / analysis*
Reg. No./Substance:
0/Caffeic Acids; 0/Coated Materials, Biocompatible; 0/Complex Mixtures; 331-39-5/caffeic acid; 50-81-7/Ascorbic Acid; 51-43-4/Epinephrine; 69-93-2/Uric Acid; 7440-44-0/Carbon

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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