NR ATJX
AU Hianik,T.; Ostatna,V.; Sonlajtnerova,M.; Grman,I.; Vaisocherova,H.; Homola,J.
TI Biosensors based on DNA aptamers - sensitive tool for protein detection
QU International Conference - Prion 2005: Between fundamentals and society's needs - 19.10.-21.10.2005, Congress Center Düsseldorf - Poster Session: Diagnosis DIA-09
PT Konferenz-Poster
AB DNA aptamers represent new tools for detection of proteins. They consist of RNA or single stranded DNA that contain specific binding site with high affinity to desired molecule, e.g. prions. This affinity is comparable with the affinity of antibodies. Recently, we have reported a novel method of detection thrombin by means of DNA aptamers using electrochemical indicators. In this contribution, we compare the method of electrochemical indicators with two other techniques - quartz crystal microbalance (QCM) and surface plasmon resonance (SPR). The SPR sensor used in this work is a recently developed 8-channel SPR sensor based on wavelength modulation and wavelength division multiplexing of sensing channels. We have investigated the influence of the method of immobilization of aptamers on sensitivity and selectivity of the trombin-aptamer binding. For this purpose the aptamers modified by SH groups were immobilized to a gold support by chemisorption, or aptamers modified by biotin were immobilized to a solid support coated with avidin, neutravidin or streptavidin utilizing high affinity of biotin to avidin, neutravidin or streptavidin. In one series of experiments we also used dendrimers as a support for immobilization of the aptamers. The influence of various conditions (pH, ionic strength) as well as influence of interferences (human serum albumin (HSA), human immunoglobuline (IgG)) has been studied. We compared the binding affinity of thrombin to the conventional aptamers and to aptamer beacons. The results obtained on antithrombin aptamer can be useful for development biosensor for detection prions in a complex biological fluids.
AD T.Hianik, V.Ostatna, M.Sonlajtnerova, I.Grman, Comenius University, Slovakia; H.Vaisocherová, J.Homola, IRE, Czech Republic
SP englisch
PO Deutschland