纸芯片固态电化学发光平台的建立及在食品安全检测中的应用研究

Development of rapid and sensitive detection techniques for food safety is greatly significant because it is closely related to the national economy and people's lives. Paper-based chip is one kind of new microfluidics, which possesses the advantages of low cost, simpleness and speediness, etc. By its capillary action, the sample transportation and filtration can be easily accomplished along the channels without any external power or moving parts. Due to the oxidation-reduction reaction mechanism of tris(2,2'-bipyridyl)ruthenium(II) electrochemiluminescence (ECL), it can be regenerated in situ at the electrode surface during the ECL process. Therefore, regenerable solid-state ECL sensors can be established by immobilizing the tris(2,2'-bipyridyl)ruthenium(II) on the electrode surface. Compared with the solution-phase ECL procedure, the immobilization approaches can reduce the consumption of expensive reagent, simplify the experimental design, and are with the advantages of high reproducibility, stability and sensitivity. The two techniques are with good compatibility, however, there has been no report on cooperation of paper-based chip and solid-state ECL sensor for food safety detection by now. Combining their advantages, this research is to develop a cost-effective, simple, rapid, highly selective and sensitive food safety detection method. Firstly, appropriate channal and three-electrode system will be desighed and integrated on the paper-based substrates and then stable efficient solid-state ECL sensor will be fabricated. The paper-based chip will provide channels and platforms for sample injection, simple pretreatment and sensitive detection. Finally, taking cocaine, tetracyclines and ochratoxin A as representatives of harmful substances in food matrix, appropriate detection modes such as direct, indirect and specific detections will be investigated. The developed methods will provide basis for establishing one system of techniques and microminiaturized instruments for rapid, effective food safety detection.

食品安全关乎国计民生，发展其快速灵敏检测技术具有重要意义。纸芯片是一种新型微流控芯片技术，它通过毛细作用带动液体流动、过滤样品，具有低耗、简单快速等优势。三联吡啶钌在电化学发光反应中具有可再生与循环利用的特性，所以可将其固定在电极表面建立固态电化学发光平台，该平台可节省试剂、简化装置，具稳定、重现、灵敏度高等优势。两类技术具有很好的兼容性和互补性，但结合用于食品安全分析尚属空白。本项目拟结合二者的优势，在纸芯片基底上集成合适的样品通道和三电极体系，并制得稳定的固态电化学发光传感器，为食品安全检测的样品进样、在线前处理、灵敏检测提供一体化通道和平台，以食品中有害物质可卡因、四环素类抗生素或赭曲霉毒素A为例，探索合适的电化学发光检测模式，如：直接检测、间接检测、特异性检测等，以实现食品中有害物质的低耗、简单快速、高选择性的灵敏检测，为发展一套食品安全实时快速检测的分析技术、微小型设备奠定基础。

食品安全关乎国计民生，发展其快速灵敏检测技术具有重要意义。纸芯片是一种新型微流控芯片技术，它通过毛细作用带动液体流动、过滤样品，具有低耗、简单快速等优势。三联吡啶钌在电化学发光反应中具有可再生与循环利用的特性，所以可将其固定在电极表面建立固态电化学发光平台，该平台可节省试剂、简化装置，具有稳定、重现、灵敏度高等优势。这两类技术具有很好的兼容性和互补性。本项目结合二者的优势，选择全纤维的色谱纸作为纸芯片的制作原料，通过照相平板印刷术，在纸芯片基底上优化设计制得亲水和疏水界面清晰的样品通道和检测池，通过丝网印刷术得到合适的三电极体系，通过不断地优化设计，制备得到高质量纸芯片。结合新材料如功能化石墨烯、碳量子点、功能化高分子等，通过离子交换、静电吸附、π-π叠加等作用，分别实现了纸芯片碳印刷电极上Ru(bpy)32+或其共反应物的固定，从而建立简单、高效、稳定的纸芯片固态电化学发光传感器，同时可通过纸芯片通道进行样品进样、在线前处理、并到达检测传感界面，采用了不同的检测模式包括：直接检测、间接检测及基于核酸适配体的特异性检测等，以实现四环素类抗生素、三丙胺等食品中有毒有害物质的灵敏检测。本项目严格按照计划书要求，在2014年1月至2016年12月项目执行期间，已顺利执行所有研究计划，超额完成了研究目标，发表SCI论文29篇，申请专利9项，发表专著1部。本项目充分发挥了纸芯片和固态电化学发光在节省试剂、简化装置等方面优势充分结合，相辅相成，获得了一系列简单快速、低耗、灵敏度高的食品中有毒有害物质的检测方法，为发展一套低耗、简单、便携、选择性高的食品安全灵敏检测的分析技术、微小型设备奠定基础。