基于金磁纳米颗粒的光磁复合效应灵敏检测尿液中结核标志物

Tuberculosis (TB) is a common and deadly infectious disease caused by Mycobacterium tuberculosis. Sensitive and simple immunoassay devices would provide an opportunity to gain new insight into detection of Mtb. In our approach to the goal, we employed an SPR and gold-magnetic nanoparticles (GMP) which has good biocompatible and optical-magnetic combined effect. Based on immunosensing, CFP-10 was selected for development of TB diagnosis. Monoclonal antibodies (Ab1) to CFP-10 were immobilized onto calixarene deritives modified Au-SPR chips. CFP-10 in urine was separated and enriched off-line by synthesized gold-magnetic particle-Ab2 bioconjugates (GMP-Ab2).The resulting GMP-Ab2-CFP-10 particles were washed with blocking buffers, then injected into an SPR flow system and captured by antibodies on the gold SPR chip. SPR was monitored continuously after injection of the GMP-Ab2-CFP-10 bioconjugates in the magnetic field. The comparing study of GMP aggregation on the chip surface and GMP sizes effect on the SPR signal and the reaction kinetics would reveal the influence of GMP's optical-magnetic combined effect on the SPR signal in an external magnetic field. The signal enhancement mechanism of GMP for SPR immunochip would be clarified. This sensitive method based on GMP amplification, using urine samples and SPR spectroscopy, is promising and can be rapidly developed into a reliable diagnostic method to monitor TB. The research results would provide basic data and the theoretical basis for in-depth study of the GMP as a signal amplification material.

结核病是由结核杆菌引起的一种常见且致命的传染病，灵敏、简便诊断结核病具有重要意义。本研究选取以生物相容性好、具有光磁两重特性的金磁纳米颗粒（GMP）为目标化合物，结合单独利用金或磁纳米颗粒构建的SPR免疫芯片均能起到信号放大的实际情况，开展以GMP作为SPR信号放大的开发灵敏芯片研究。首先通过自组装技术把CFP-10的一抗定向吸附到金膜表面；然后通过GMP与CFP-10的二抗共孵育，与尿样中存在的结核标志物CFP-10相结合，在外磁场作用下分离富集；进而与芯片上一抗特异性相互作用，在外加磁场下检测SPR信号变化。通过对芯片表面GMP聚集情况、不同大小GMP对SPR信号和反应动力学的影响，揭示尚不清楚的在外磁场作用下GMP光磁复合效应对SPR信号影响，阐明GMP对SPR免疫芯片信号增强规律，构建高灵敏的尿液中结核标志物检测SPR芯片，从而为GMP作为传感器信号放大材料的深入研究提供基础数据。

本项目以常见且致命的传染病即结核病为研究对象，开发了灵敏、简便诊断结核病的传感器。以生物相容性好、具有光磁两重特性的金磁纳米颗粒（GMP）为目标化合物，结合单独利用金或磁纳米颗粒构建的SPR免疫芯片均能起到信号放大的实际情况，开展以GMP作为SPR信号放大的开发灵敏芯片研究。首先通过自组装技术把CFP-10的一抗定向吸附到金膜表面；然后通过GMP与CFP-10的二抗共孵育，与尿样中存在的结核标志物CFP-10相结合，在外磁场作用下分离富集；进而与芯片上一抗特异性相互作用，在外加磁场下检测SPR信号变化。通过对芯片表面GMP聚集情况、不同大小GMP对SPR信号和反应动力学的影响，揭示尚不清楚的在外磁场作用下GMP光磁复合效应对SPR信号影响，阐明GMP对SPR免疫芯片信号增强规律，构建了高灵敏的尿液中结核标志物检测SPR芯片，为GMP作为传感器信号放大材料的深入研究提供基础数据。本项目还研究了其他多功能纳米材料比如NiO和复合蛋白纳米管作为信号放大元件在SPR中的应用，并成功的构建了TB检测免疫芯片。