基于功能化重组铁蛋白的免疫分析信号放大系统的研究

Signal amplification system plays a vital role in the development of novel immunoassay methods with high sensitivity. However, the amplification efficiency of traditional enzyme labeled secondary antibody-based signal amplification is unsatisfactory; the new signal amplification systems based on nano-materials have better performance but with the drawback of potential nanotoxicity. Therefore, it is of great need to develop nanomaterial-independent and efficient signal amplification strategies. This project intends to introduce recombinant protein technology, take ferritin as the target, and fuse antibody recognition unit and signal output unit with ferritin to construct dual-functional recombinant ferritin with antibody binding property and signal output function. The fact that recombinant ferritin consists of multiple subunits endows it with the advantages of multi binding sites and multi-signal amplification effect. Therefore, combined with piezoelectric, optic and electrochemical sensing technology, it is expected to develop versatile signal amplification system based functional recombinant ferritin. Furthermore, on the basis of this signal amplification, this project plans to develop novel immunoassays and apply to the detection of food-borne pathogens in agricultural products.

高效的信号放大系统对发展高灵敏度的免疫分析新方法具有重要意义。然而，传统的酶标二次抗体信号放大效果不理想，新型基于纳米材料的信号放大系统又面临潜在的纳米毒性风险，因此亟待发展非纳米材料依赖的高效信号放大策略。本项目拟引入重组蛋白技术，以可融合表达的铁蛋白为载体，将抗体识别单元、信号输出单元与铁蛋白亚基融合表达，构建具有抗体识别功能和信号输出功能的双功能重组铁蛋白。并基于铁蛋白多亚基特性获得的多重识别/信号放大能力，结合压电、光、电化学等手段，发展基于功能化重组铁蛋白的通用型免疫信号放大系统，藉此研制高灵敏的免疫传感新方法，进一步应用于农产品中食源性致病菌的检测。

高效的信号放大系统对发展高灵敏度的生物新方法具有重要意义，相关研究在临床诊断和食品全领域具有潜在的应用价值和迫切需求。针对这一需求，本课题利用重组蛋白质及纳米材料开发高效的信号转换放大系统，并进一步基于该信号放大系统发展生物传感新方法。本课题将脲酶的高效催化活性和抗菌肽的高亲和力识别作用相结合，完成了基于蛋白质分子工具的信号放大系统的构建，并基于此发展了快速、灵敏检测食源性致病菌的生物传感新方法。本课题还利用新型二维材料碳化钛MXenes的广谱、高效荧光猝灭能力，发展了基于碳化钛MXenes的荧光生物传感平台，应用于蛋白质和核酸等重要生物标志物的检测，并实现了活细胞中糖蛋白和microRNA等标志物的实时原位荧光成像，为研究不同标志物之间相互作用关系以及相关疾病的早期诊断和监测提供了新方法。