农药的大量使用已经对人类和环境造成了严重的危害，对生物多样性构成了巨大威胁，因此，发展高效和易于推广的农药残留检测技术具有十分重大的意义。本项目利用硅量子点（SiQDs）的类过氧化物酶催化性质，结合农药分子与其适配体（Aptamer）的特异性作用，设计构建比色传感器用于高灵敏的农药检测。含有农药特定序列的Aptamer通过静电作用在SiQDs的表面进行组装，使SiQDs类酶活性处于“Turn-off”状态，当目标物（农药）存在时，Aptamer与农药特异性作用并脱离SiQDs表面，SiQDs的类酶活性恢复而处于“Turn-on”状态，并催化过氧化氢氧化底物显色，从而实现农药的比色检测，以此建立简便、快速、低成本、易于推广的高灵敏农药残留分析新方法。本项目的实施不仅能拓展SiQDs纳米材料的应用范围，同时为环境中农药残留分析提供技术支持，具有重大的基础理论意义和实际应用价值。

The abundant use of pesticides has caused serious harm to humanity and the environment, and posed a tremendous threat to biodiversity, thus it is of great significance to develop highly efficient and easy to spread means for the detection of pesticide residues. Motivated by these severe situation above, by using the peroxidase-like catalytic ability of Si quantum dots (SiQDs) and the specificity effect of the pesticide molecules with aptamer, the aim of this project is to develop colorimetric sensing platform for the high sensitive detection of pesticides. The peroxidase-like activity of SiQDs can be turned-off by blocking its surface through the assembly of pesticide-specific aptamer sequences; however, in the presence of target (pesticide), the aptamer sequences leave the SiQDs surface in a pesticide concentration-dependent manner, reactivating SiQDs peroxidase-like activity, and the peroxidase-like activity of SiQDs can be turned-on again. H2O2 can oxidate chromogenic substrates under the catalytic of SiQDs, and the colorimetric method for the detection of pesticides is realized. Based on this mechanism, the simple, rapid and inexpensive colorimetric sensor is established, and also we provide a new method for high sensitive colorimetric determination of pesticide residues. The implementation of this project is not only of significant value for developing the application of SiQDs, but also provide technical support for the analysis of pesticide residues in the environment, and has the great significance in scientific theory and practical application.