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QCM Immunosensor Based on Polyamidoamine Dendrimers
Author(s) -
Svobodová Lenka,
Šnejdárková Maja,
Polohová Vladimíra,
Grman Igor,
Rybár Peter,
Hianik Tibor
Publication year - 2006
Publication title -
electroanalysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.574
H-Index - 128
eISSN - 1521-4109
pISSN - 1040-0397
DOI - 10.1002/elan.200603623
Subject(s) - quartz crystal microbalance , dendrimer , biosensor , monolayer , poly(amidoamine) , chemistry , detection limit , surface modification , protein g , materials science , chemical engineering , chromatography , amidoamine , nanotechnology , antibody , polymer chemistry , adsorption , organic chemistry , engineering , immunology , biology
The poly(amidoamine)(PAMAM) dendrimers of fourth generation (G4) and 1‐hexadecanethiol (HDT) has been used for formation of self assembled monolayers on a gold surface for preparation of quartz crystal microbalance (QCM) immunosensor for detection of human IgG. The anti‐IgG antibodies were immobilized on a surface of G4‐HDT layers or those covered by Protein A. In later case the oriented immobilization of anti‐IgG takes place due to preferred interaction of F c portion of antibodies with the Protein A. The detection limit in a flow mode was 7 nM both for biosensor with and without Protein A. However, in the case of Protein A the number of bounded Ab was 1.4 times lower in comparison with those without Protein A. Thus, the sensitivity of the Protein A based sensor was higher due to orientation effect in comparison with randomly oriented Ab at a dendrimer surface without Protein A. Increased concentration of IgG and formation of Ab‐Ag complexes resulted in increase of motional resistance, that suggest increased contribution of viscoelasticity, as revealed from impedance analysis. The most important property of the immunosensor was its ability for regeneration using 0.1 M glycine‐HCl.