来自驼科动物的纳米抗体亲和力高、稳定性好，对样品及检测环境具有高适应性，且易于在分子水平改造，在食品免疫分析中优势突出。我们在前期研究中发现，通过构建免疫抗体库筛选纳米抗体受限于动物免疫、药物分子量、毒性及免疫原有效性等问题，使得小分子化学污染物的纳米抗体制备效率低、成本高。针对此，本研究提出基于全合成纳米抗体库筛选小分子化学污染物纳米抗体的新策略。拟开展：(1)利用生物信息统计分析小分子纳米抗体序列构成规律，理性设计与构建一个通用型全合成纳米抗体库；(2)以“超小分子”—丙烯酰胺为代表性研究对象，筛选其特异性纳米抗体，并通过三维模建-分子对接确定抗体-药物相互作用的关键氨基酸位点，对其突变进化；(3)基于重组仿生磁性铁蛋白模拟酶定向标记纳米抗体，进而建立丙烯酰胺非酶标记免疫分析模式等3方面的研究。本项目将对创新免疫分析核心试剂，推进食品中小分子有害物快速检测技术具有重要意义。

Single domain antibodies (Abs) naturally present in camelids, referred to as nanobodies (Nbs), have advantages over conventional monoclonal Abs in their high affinity and specificity, better stability, high solubility and convenience to molecular modification, so Nbs are more suitable in robust behaviors such as immunoassay for food sample, in which components are more complex and matrix effects are more seriously. Based on the previous study, we found Nbs selection from immune library is always limited by animals, molecular weights and toxicities of antigens, therefore it is high cost and low efficiency to prepare Nbs for small-molecule chemical contaminants exist in food sample. So, in order to breakthrough the bottleneck of Nbs production for small molecular chemical contaminants in food, we proposed a new strategy to select Nbs by through full-synthesized library. Our study will focus on the following three aspects: (1) analysis of the regular pattern of the Nbs sequence by through bioinformatics and rational design and construction of a full-synthesized Nbs library specially against haptens (2) Selection of Nbs for the acrylamide and its evolution based on mutation of key amino acid residues recognized target drug identified by 3D modeling and docking; (3) directed labeling the Nbs with recombinant magnetoferritin and establishment of non-enzyme labeling immunoassay method for acrylamide. The study will be significant in innovating the core reagents used in immunoassay and promoting technological advances in the field of food safety rapid detection.