Aptamers and biosensors.
The immobilization procedure to a biosensor surface has a major influence on the measurement results. To characterize the immobilization onto various biolayers, the interaction of DNA anti-thrombin aptamer with the protein thrombin was used as a model system. The aptamer was immobilized to a two-dimensional alkanethiol SAM via carboxylamide bonds and to a three-dimensional dextran matrix via streptavidin-biotin interaction. The calculated K (D) values of about 260 and 267 nM, respectively, were comparable, while the amount of bound analyte varied by a factor of 2, depending on the accessibility of the immobilized aptamer. Differences in the specificity were shown by use of the similar protein elastase.
Biosensor GmbH, Bonn, Germany.
Thomas M A
TM
Gronewold
D000473:Alkanes / Q000737:chemistry; D052157:Aptamers, Nucleotide / Q000737:chemistry* / Q000378:metabolism*; D015374:Biosensing Techniques / Q000379:methods*; D001710:Biotin / Q000378:metabolism; D003911:Dextrans / Q000737:chemistry; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry; D011485:Protein Binding; D012680:Sensitivity and Specificity; D019809:Streptavidin / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry; D013917:Thrombin / Q000378:metabolism*
D000473:Alkanes; D052157:Aptamers, Nucleotide; D003911:Dextrans; D013438:Sulfhydryl Compounds; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D001710:Biotin; D019809:Streptavidin; D013917:Thrombin