基于纳米金适配体传感器的激光诱导检测凝血酶

Determination of thrombin by laser induction based on gold nanoparticleaptamer sensor

利用激光可使纳米金修饰的双链DNA(dsDNA)去杂化和适配体的特异性,设计了一种新颖、稳定、可控且高灵敏的凝血酶检测方法。将两端分别修饰金纳米粒子与荧光标记物的核酸适配体与其互补链杂化制成稳定的dsDNA传感器,当凝血酶存在时,通过激光触发传感器去杂化释放适配体并与凝血酶结合,拉近金纳米粒子与荧光标记物的距离,产生猝灭使荧光信号发生变化。对激光照射时间、激光输出功率、温育时间等条件进行优化。在最优条件下,荧光强度变化值(ΔI)与凝血酶浓度在0.55~33 nmol/L范围内呈现出良好的线性关系,其线性回归方程为y=0.0082x+0.2714,相关系数R^2为0.98,血清中加标回收率为95.5~102.7%,且溶菌酶等无明显干扰。该方法可作为凝血酶的检测方法。

A novel,stable,controllable and sensitive method for thrombin detection was designed based on the gold nanoparticle-modified double-stranded DNA(dsDNA)dehybridized by laser and specific aptamer.A nucleic acid aptamer which was respectively labeled by a fluorescein and a gold nanoparticle on its terminals was hybridized with its complementary strand to form a stable dsDNA sensor.When thrombin was present,the sensor was dehybridized by laser to release the aptamer and binded with thrombin,with resulted closer distance between the labeled gold nanoparticles and the fluorescien.This led to quench,wich changed the fluorescence signal.The conditions such as laser irradiation time,laser output power,and incubation time were optimized.Under the optimal conditions,satisfied linear relationship between the fluorescence intensity change value(ΔI)and the thrombin concentration was obtained in the range of 0.55-33 nmol/L.The linear regression equation was y=0.0082 x+0.2714,and the coefficient R^2 was 0.98.The spiked recoveries in serum assays were 95.5%-102.7%,and these results were undisturbed by the presence of lysozyme.This strategy can be employed as a determination method for thrombin.