基于Ru(bpy)32+-SiO2纳米颗粒的核酸适配体传感器对凝血酶的电致化学发光检测

本文应用核酸适配体构建了一种新型的电致化学发光检测蛋白体系。两个核酸适配体结合凝血酶的两个不同位点，利用这两核酸适配体与凝血酶的高亲和力构建三明治传感体系检测凝血酶。一个核酸适配体固定在金电极上用来捕获凝血酶，另一个标记有包裹电致化学发光活性物Ru(bpy)₃²⁺的二氧化硅纳米颗粒，用来检测电致化学发光信号。此核酸适配体传感器对凝血酶具有特异识别性，电致化学发光信号与凝血酶的浓度直接相关，非特异性识别的牛血红蛋白、牛血清白蛋白不干扰测定。由于在检测的核酸适配体上标记的纳米颗粒包裹有多个发光活性物，因此大大提高了发光效率和灵敏度，此法对凝血酶的线性响应范围为2.0 fmol•L^-1～2.0 pmol•L^-1，检测限可达1.0 fmol•L^-1。

Ru(bpy)32+‐doped Silica Nanoparticle Aptasensor for Detection of Thrombin Based on Electrogenerated Chemiluminescence

A new electrogenerated chemiluminescent (ECL) detection system for protein using the aptamers was developed. Two different aptamers, which recognize different positions of thrombin, were chosen to construct sandwich type sensing system for protein, one was immobilized onto the gold electrode for capturing thrombin onto the electrode and the other was used for detection. To obtain the signal, the aptamer for detection was labeled with tris(2,2′‐bipyridyl)ruthenium(II)‐doped silica nanoparticles (Ru(bpy)₃²⁺‐doped SNPs). The increase of the ECL signal generated by Ru(bpy)₃²⁺‐doped SNPs was observed in dependent manner on the concentration of thrombin added. Bovine serum albumin and bovine hemoglobin had almost negligible responses. The assay allows detection at levels as low as 1.0 fmol·L^?1 of the thrombin due to that there are a large number of Ru(bpy)₃²⁺ molecules inside SNPs labeled on the aptamer used for detection. The ECL signal was linearly related to the concentration of the thrombin analyte in the range of 2.0 fmol·L^?1 to 2.0 pmol·L^?1.