We report on a new type of artificial receptor formed by hybridization of two DNA aptamers for human thrombin (aptabody). This aptasensor based on multiwalled carbon nanotubes allowed us to detect thrombin with detection limit of 0.3 nM, which was 3 times better in comparison with conventional aptamer.
Novel affinity biosensors for detecting cellular prions, PrP(C), based on DNA aptamers and antibodies immobilized onto the carbon nanotubes have been designed and compared in accordance with their binding ability and analytical performance. The biosensors allowed us to detect PrP(C) with the limits of detection of 20 to 50 pM.
Using an acoustic method we showed that the aptamer configuration, especially those comprised of dimers with binding exosites sensitive to heparin and fibrinogen at thrombin, substantially increases the aptasensor sensitivity.
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.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.