Abstract: Thrombin is an important enzyme in physiology. It palys an important role in some physiological and pathological process, such as blood solidification, wound cicatrization and inflammation. Therefore, thrombin detection is very important in medicine. A novel nano-biosensor based on aptamer was designed and thrombin detection with sandwich-type based on magnetic separation was proposed. The equation of calibration plot is I=09758×1011c-668 in the concentration range of 2.24×10^-11—4.03×10^-9 mol/L and the detective limit is 1×10^-11 mol/L of thrombin. The relative standard deviation(n=10) was 2.56%. The fluorescence intensity obtained was very stable, even no attenuation observed after 24 h. The experiments results demonstrate that the proposed method possesses the feasibility, high specificity and sensitivity. It is also hopeful to be applied to the field of biomedicine.

Key words: Aptamer, Thrombin, Magnetic nanoparticle, Fluorescence