NR AWOC
AU Sonlajtnerova,M.; Grman,I.; Hinaik,T.
TI DNA aptamers based biosensors for detection proteins in blood plasma
QU International Conference - Prion 2006: Strategies, advances and trends towards protection of society - 3.10.-6.10.2006, Torino, Italy, Lingotto Conference Centre - Poster sessions DIA-47
PT Konferenz-Poster
AB DNA aptamers are single stranded nucleic acids with specific binding sites for proteins. They can be immobilized onto a solid support, e.g. by avidin-biotin technology. This aptasensor can be used for detection biologically important proteins, e.g. prions. So far the effectivity of aptamers was demonstrated mostly in buffers but not in a complex biological liquids, e.g. in blood or blood plasma. In this work we examined the sensitivity of detection the protein in a blood plasma using aptamer specific for thrombin. Two basically different methods were used for detection - the method based on electrochemical indicators and the method based on quartz crystal microbalance (QCM). We also examined how the structure of the aptamers affect the protein binding and optimized the method of regeneration of the sensor surface. Finally the sensor was tested in blood plasma of a health donors. We showed, that using the electrochemical indicator - methylene blue - and diffential pulse voltammetry (DPV) or chronocoulometry (CC) it is possible to detect human thrombin wih detection limit of 100 pM. The DPV method was, however more sensitive. The aptamer used selectively binded the heparing binding site of the thrombin. This has been proved in experiments in which the heparinthrombin complexes were investigated. 2 M NaCl was effectively used for sensor regeneration. After this treatment the sensor can be used at least three times with similar sensitivity. The results obtained can be applied for another aptamer based biosensors, e.g. for detection prions. Detection of thrombin in blood plasma caused certain difficulties. Possibilities of improvement sensor sensitivity in blood plasma is discussed.
AD Department of Nuclear Physics and Biophysics, FMFI UK, Mlynska dolina F1, 842 48 Bratislava, Slovakia. Email: hianik@fmph.uniba.sk
SP englisch
PO Italien