本项目立足于功能纳米材料对酶联免疫吸附法（ELISA）的改进，拟设计一种灵敏稳定的信号探针用于食品中黄曲霉毒素B1的可视化检测。主要研究内容如下：1）基底改进——通过席夫碱反应将AFB1适配体修饰在纳米磁珠的表面，制备特异性识别的磁性基底，实现磁分离和磁富集一体化；2）信标改进——将多孔纳米二氧化硅负载的Au-Pt纳米酶(Au-Pt/m-SiO2)作为酶标记物代替传统ELISA中的HRP酶，以提高传统ELISA的灵敏度；3）显色改进——探索新的显色试剂，解决传统ELISA显色单一性问题，进而构建一种基于磁富集和纳米酶催化的新型可视化检测系统。该方法将磁性基底物、纳米酶标记物和显色新试剂三部分有效结合起来，能够实现对传统ELISA的综合改进，从而提供一种灵敏快速的可视化分析方法。此外，该可视化分析方法有望应用于食品中痕量有害物质的快速检测和重大疾病的早期诊断。

In this research, on the basis of functional nanoparticles, a kind of signal label with high stability and sensitivity is proposed for improving ELISA performance, which is supposed to realize the visual detection of AFB1 in food samples. The main contents of the research are listed as follows, 1) Substrate improvement: to specifically bind with the target and capture them from samples by magnetic enrichment, AFB1 aptamers are conjugated to the surface of magnetic beads (MBs) via Schiff base reaction; 2) Signal improvement: to enhance the sensitivity of conventional ELISA, Au-Pt/m-SiO2 with intrinsic peroxidase-like activity (nanoenzyme) act as labels to replace HRP conjugated antibody; 3) Colouring improvement: to solve monochromic problem of TMB/H2O2 system, a new coloring system with multicolor variations is explored, based on which a new visual analytical system can be developed with the enrichment of magnet and the catalysis of nanoenzyme. This method unites effective magnetic substrate, nanoenzyme labelled signal and new colouring agents together to improve the conventional ELISA, which provides a new strategy for the construction of a simple and sensitive detection method. In addition, this strategy can be further applied in the sensitive and rapid detection of trace toxic substance in food and the early diagnosis of critical diseases.