适配体调控“Turn-off/Turn-on”硅量子点类酶活性的农药残留比色传感研究

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.

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。

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。本项目基于硅量子点的优越性能，采用不同方法制备了各种不同组分和形貌的硅量子点，通过控制实验条件，制备了各种基于硅量子点的纳米探针如氮掺杂硅量子点探针、硅量子点/纳米银探针和氮掺杂硅量子点/纳米银探针等。以这些探针为敏感光学元件，通过调控各步骤实验参数和条件使这些探针具有优越的传感性能，构建了系列农药及其有机污染物的比色/荧光传感新方法。基于这些方法所获得的检测限和线性范围优于许多已经报道的方法，其为可为农药及其相关污染物的实际低痕量分析提供新的技术手段。本项目经过三年的研究，本项目在analytical chemistry、biosensors and bioelectronics发表相关SCI论文十余篇篇，有9篇影响因子大于9.0，一区6篇。通过本项目的研究，所发展的系列比色/荧光传感方法有望在环境等各领域的农药物及其它污染物高灵敏检测中得到广泛应用，具有较重要的潜在应用价值。