| Popis: |
Aptamers are synthetic single-stranded oligonucleotides which bind specifically to their target. They offer several advantages over antibodies. For example, aptamers can be produced under unphysiological conditions against almost any target, including toxic or pathological substances. They are also quicker and cheaper produced than antibodies, and are easy to modify without loss of activity. Furthermore, they exhibit high stability under a width range of conditions. Consequently, they make excellent receptors for the use in biosensors. This article describes the evaluation of a novel aptasensor based on the Surface Plasmon Resonance (SPR)-system developed by the Fraunhofer Institute for Applied Optics and Precision Engineering IOF (Jena, Germany) using a thrombin-aptamer interaction as a model system. The biotin-tagged aptamer was attached to the sensor's gold surface by means of its interaction with streptavidin. Thrombin solutions of different concentrations were pumped over this surface, and the interaction was measured under buffer flow. The binding signals for the thrombin-aptamer interaction were compared to those arising from a control random-oligonucleotide of the same size and bearing the same modifications. Using this approach, we were able to obtain reproducible, significant and stable signals with a limit of detection of about 26 nmol/L. |
