Document Detail

Development of a highly enantioselective capacitive immunosensor for the detection of alpha-amino acids.
MedLine Citation:
PMID:  17073432     Owner:  NLM     Status:  MEDLINE    
This work describes a highly enantioselective and sensitive immunosensor for the detection of chiral amino acids based on capacitive measurement. The sensor was prepared by first binding mercaptoacetic acid to the surface of a gold electrode, followed by modification with tyramine utilizing carbodiimide activation. The hapten 4-amino-D-phenylalanine was then covalently immobilized onto the electrode by diazotization. Stereoselective binding of an anti-D-amino acid antibody to the hapten-modified sensor surface resulted in capacitance changes that were detected with high sensitivity by a potentiostatic step method. Using capacitance measurement, detection limits of 5 pg of antibody/mL were attained. The exquisite stereoselectivity of the antibody was also utilized in a competitive setup to quantitatively determine the concentration of the analyte d-phenylalanine in nonracemic samples containing both enantiomers of this amino acid. Trace impurities of d-phenylalanine as low as 0.001% could be detected.
Song Zhang; Jingjing Ding; Ying Liu; Jilie Kong; Oliver Hofstetter
Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  Analytical chemistry     Volume:  78     ISSN:  0003-2700     ISO Abbreviation:  Anal. Chem.     Publication Date:  2006 Nov 
Date Detail:
Created Date:  2006-10-31     Completed Date:  2007-04-19     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  0370536     Medline TA:  Anal Chem     Country:  United States    
Other Details:
Languages:  eng     Pagination:  7592-6     Citation Subset:  IM    
Department of Chemistry, Fudan University, Shanghai 200433, People's Republic of China.
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MeSH Terms
Amino Acids / analysis*
Biosensing Techniques*
Phenylalanine / analogs & derivatives
Reg. No./Substance:
0/Amino Acids; 0/Haptens; 2410-24-4/4-aminophenylalanine; 63-91-2/Phenylalanine

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

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