基于免疫磁珠和微流控协同增敏高通量阻抗生物传感方法快速检测食源性致病菌研究

In this project we propose a novel impedimetric immunoassay method for high-throughput and rapid detection of foodborne pathogens in complex samples. In this approach, firstly, the target bacteria in the sample are captured on the magnetic beads with antigen/antibody reaction. Then, the immunomagnetic beads without targets are separated to eliminate nonspecific signals through the nano/micro channels. Finally, impedimetric measurement signals are carried out to detect target bacteria in the sample which are synergistic sensitizized by microfluidic and immunomagnetic beads. In this project, we will investigate 1) fabrication and promotion of multichannel microelectrode; 2) immunomagnetic separation methodology for foodborne pathogens under complex background; 3) non-target binding immunomagnetic beads separation mechanism under nano/micro channels; 4) research of microfluidic and immunomagnetic beads synergistic sensitizized impedimetric biosensing analysis; 5) the equivalent circuit detection model for foodborne pathogens. This method is capable of handling complex food samples. And it has the advantages such as short response time, high sensitivity, and simple measurement setup, which facilitates its applications on rapid screening of food samples. In this project, common foodborne pathogens are selected as detection targets. At the same time, this method can also be easily extended to the detection of other targets in food or environment samples. To our knowledge, there is no report of such method in the literatures up to now.

本项目提出一种在复杂背景下高通量、高灵敏快速检测食源性致病菌的阻抗生物传感新方法。该方法先采用免疫磁分离技术来快速浓缩和分离致病菌，然后采用微纳通道进一步消除空白免疫磁珠对阻抗检测信号的影响。最后通过绑菌免疫磁珠和微流控通道的灵敏度协同调控，建立高灵敏、稳定的阻抗检测方法。研究主要内容包括：1）多通道微电极的制备与优化；2）微纳磁珠对复杂背景下致病菌的分离和富集规律；3）空白微纳磁珠在微纳通道中的分离机理与调控方法；4）绑菌微纳磁珠与微流控通道协同增敏机制研究；5）致病菌检测等效电路模型研究。该方法对待测目标能进行有效预处理，具有分离速度快、灵敏度高、装置体积小、检测结果稳定等优点，能够满足食源性致病菌快速检测和筛查的需要。在项目实施过程中，选用常见致病菌作为检测目标。同时，该方法也可以方便地拓展到食品或环境样本中其他有害因子的检测中去。根据我们的了解，目前国内外还未有相似方法的研究报道。

食源性疾病已成为目前国际上最突出的公共卫生问题之一，研发可用于现场快速检测的技术或仪器是减少我国食品安全事件，确保人们健康的重要举措。基于阻抗分析技术的生物传感器具有无需标记、快速、易于自动化等特点已经在食品安全检测中体现其突出的技术优势。但是该技术存在检测仪器体积大、设备价格昂贵，检测电极成本较高，阻抗信号灵敏度和稳定性较差等问题。针对这些挑战，本项目研发了小型阻抗检测系统，研发了新型检测电极、制备了用于样品高效前处理的磁性材料，构建了微流控装置，探索了检测等效电路模型以及阻抗信号协同增敏方法。本项目尝试为解决食品安全现状提供了一种新的检测技术，具有理论研究和实际应用价值。