PMID- 18586483
OWN - NLM
STAT- MEDLINE
DCOM- 20090212
LR  - 20191210
IS  - 1873-4235 (Electronic)
IS  - 0956-5663 (Linking)
VI  - 24
IP  - 4
DP  - 2008 Dec 1
TI  - Electrochemical selective determination of ascorbic acid at redox active polymer 
      modified electrode derived from direct blue 71.
PG  - 518-23
LID - 10.1016/j.bios.2008.05.007 [doi]
AB  - A simple selective method for determination of ascorbic acid using polymerized 
      direct blue 71 (DB71) is described. Anodic polymerization of the azo dye DB71 on 
      glassy carbon (GC) electrode in 0.1M H(2)SO(4) acidic medium was found to yield 
      thin and stable polymeric films. The poly(DB71) films were electroactive in wide 
      pH range (1-13). A pair of symmetrical redox peaks at a formal redox potential, 
      E('0)=-0.02V vs. Ag/AgCl (pH 7.0) was observed with a Nernstian slope -0.058V, is 
      attributed to a 1:1 proton+electron involving polymer redox reactions at the 
      modified electrode. Scanning electron microscope (SEM), atomic force microscope 
      (AFM) and electrochemical impedance spectroscopy (EIS) measurements were used for 
      surface studies of polymer modified electrode. Poly(DB71) modified GC electrode 
      showed excellent electrocatalytic activity towards ascorbic acid in neutral 
      buffer solution. Using amperometric method, linear range (1x10(-6)-2x10(-3)M), 
      dynamic range (1x10(-6)-0.01M) and detection limit (1x10(-6)M, S/N=3) were 
      estimated for measurement of ascorbic acid in pH 7.0 buffer solution. Major 
      interferences such as dopamine and uric acid are tested at this modified 
      electrode and found that selective detection of ascorbic acid can be achieved. 
      This new method successfully applied for determination of ascorbic acid in 
      commercial tablets with satisfactory results.
FAU - Kumar, S Ashok
AU  - Kumar SA
AD  - Department of Chemical Engineering and Biotechnology, National Taipei University 
      of Technology, No. 1, Section 3, Chung-Hsiao East Road, Taipei, 106, Taiwan, ROC.
FAU - Lo, Po-Hsun
AU  - Lo PH
FAU - Chen, Shen-Ming
AU  - Chen SM
LA  - eng
PT  - Evaluation Study
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
DEP - 20080528
PL  - England
TA  - Biosens Bioelectron
JT  - Biosensors & bioelectronics
JID - 9001289
RN  - 0 (Azo Compounds)
RN  - 0 (Polymers)
RN  - MA5K8N8952 (Direct Blue 71)
RN  - PQ6CK8PD0R (Ascorbic Acid)
SB  - IM
MH  - Ascorbic Acid/*analysis/chemistry
MH  - Azo Compounds/*chemistry
MH  - Biosensing Techniques/*instrumentation/methods
MH  - Electrochemistry/*instrumentation/methods
MH  - Equipment Design
MH  - Equipment Failure Analysis
MH  - Oxidation-Reduction
MH  - Polymers/chemistry
MH  - Reproducibility of Results
MH  - Sensitivity and Specificity
EDAT- 2008/07/01 09:00
MHDA- 2009/02/13 09:00
CRDT- 2008/07/01 09:00
PHST- 2008/03/03 00:00 [received]
PHST- 2008/05/01 00:00 [revised]
PHST- 2008/05/20 00:00 [accepted]
PHST- 2008/07/01 09:00 [pubmed]
PHST- 2009/02/13 09:00 [medline]
PHST- 2008/07/01 09:00 [entrez]
AID - S0956-5663(08)00246-7 [pii]
AID - 10.1016/j.bios.2008.05.007 [doi]
PST - ppublish
SO  - Biosens Bioelectron. 2008 Dec 1;24(4):518-23. doi: 10.1016/j.bios.2008.05.007. 
      Epub 2008 May 28.