基于工具酶信号放大技术电化学发光法检测凝血酶

利用巯基乙胺将合成的金纳米粒子氨基化;基于纳米粒子负载羧基化的联吡啶钌和巯基DNA制得电化学发光信号探针;采用酶循环信号放大技术,获得大量含新增DNA的溶液来捕获信号探针;以金电极为载体,将巯基DNA自组装到电极表面,依次杂交互补DNA和信号探针,构建电化学发光生物传感器.在优化的条件下,此传感器对凝血酶具有良好的响应,在3.0× 10-13～6.0×10-11 mol/L范围内,凝血酶的浓度与发光强度呈良好的线性关系,检出限为1.8× 10-13 mol/L(3a).采用酶切循环放大技术制备的生物传感器具有灵敏度高,选择性和重现性良好等特点.

Electrochemiluminescence Biosensor for Detection of Thrombin Using Enzyme-based Signal Amplification

Amino functionalized gold nanoparticles(GNP) were synthesized in this work.Electrochemiluminescence(ECL) probe was synthesized by covalently linking tris(2,2-bipyridyl) ruthenium(Ⅱ) and self-assembly of thiol DNA5 to this GNP.By using nicking endonuclease signal amplification technology,large amount of newly obtained DNA fragments was obtained to capture ECL probe.Thiol DNA probe was self-assembled on gold electrode surface,and then ECL biosensor was fabricated by sequentially hybridization of complementary DNA(newly obtained DNA fragment) and ECL probe to this modified gold electrode.Under optimized conditions,the ECL intensity of this biosensor exhibited linear relationship with thrombin concentration in the range of 3.0×10-13-6.0×10-11 mol/L,and the detection limit was 1.8×10-13 mol/L(3σ).The biosensor shows good application prospect in the field of biological samples analysis owing to its high sensitivity,good stability and reproducibility.