基于主客体竞争模式的凝血酶适配体传感器的研究

Preparation of Thrombin Aptamer Sensor Based on Host Guest Competition Model

基于β-环糊精(β-CD)主客体竞争模式,构建了开关型凝血酶适配体电化学传感器。将末端修饰了二茂铁(Fc)的核酸适配体通过与β-CD的主客体识别固定在金电极表面,当凝血酶存在时,适配体由原来的直立线状构型变为"G-四链体",远离电极表面,适配体探针的氧化还原电流强度减小,即"Signal-off"。利用此效应对凝血酶进行了灵敏检测,结果表明,在5.0×10^(-13)~5.0×10^(-9)mol/L浓度范围内,凝血酶的浓度与电化学响应信号呈良好的线性关系,检出限为2.0×10^(-13)mol/L(3σ)。与其它蛋白分子相比,本方法对凝血酶蛋白的检测具有高特异性。本传感器构建简单,再生性好,为生物血清样本中凝血酶的实时高效检测提供了方法。

A switch thrombin aptamer sensor was constructed based on the host-guest competition mode ofβ-cyclodextrin（β-CD）.The aptamer that modified with ferrocene（Fc） at its terminal was fixed on the surface of the gold electrode via the host-guest recognization with β-CD.When thrombin was present,the configuration of aptamer transformed from vertical linear to ＂G-quadruplex＂and far away from the electrode surface,which resulted in a decrease in the redox current of the aptamer probe and produce ＂ Signal-off＂ effect.On the basis of this,a high sensitive detection of thrombin was made.The detection result indicated that the thrombin concentration had a consideration linear response to the signal of aptasensor between 5.0×10^（-13）-5.0×^（-9）mol/L,and as low as 2.0×10^（-13）mol/L thrombin had been detected.This method for thrombin detection showed a higher specificity compared to other protein molecules.Besides,the sensor was constructed easily and possessed excellent regeneration,which provided a significant platform for highly efficient real-time detection of thrombin in biological serum samples.