高灵敏度高选择性环糊精量子点探针的构筑及对食品中芳(杂）环类农兽药残留的识别机理研究

Currently, there is no rapid and reliable method for detecting aromatic and heterocyclic pesticide and veterinary drug residues in food. Quantum dots (QDs) are used as fluorescent probes in recent years which are rapid and sensitive in analysis, but its application in food safety detection field is still under development. Low sensitivity, poor stability and narrow detection range of the present QDs probes are responsible for this situation. In this study, based on the concept of molecular design and the effective molecular recognition abilities of cyclodextrin (CD), amphiphilic CD will be designed, synthesized and self-assembled onto the surface of QDs by a “one-step” method of ligand exchange. Consequently, the cyclodextrin modified QDs (CD-QDs) probe with fluorescence properties and multiple-molecular recognition abilities will be prepared. Meanwhile, through the theories of quantum chemistry and structural chemistry, it will be investigated that the mechanisms of molecular recognition and signal conversion between probe and analytes. In addition, the effect of detecting environment on the sensitivity、specificity and stability of CD-QDs probe will be investigated. Based on these results, effective and stable probes will be prepared and screened. This study will provide scientific basis for design of rapid, sensitive, stable and specific detecting method toward aromatic and heterocyclic pesticide and veterinary drug residue in food safety field.

目前国内外尚无快速可靠的芳（杂）环类农兽药残留检测方法，量子探针是近年来兴起的快速灵敏的新型荧光分析技术，但在食品安全检测领域的应用还处于初步研究阶段。困扰这一问题的是现有的量子探针存在灵敏度低、稳定性差及检测范围窄等缺陷。本项目引入分子设计理念，利用环糊精具有高效的分子识别能力的特性，采用配体交换“一步法”将两亲性环糊精组装到量子点表面，制备出兼具量子点荧光特性及环糊精多分子识别能力的探针。同时，采用量子化学和结构化学的理论和方法，从分子角度解析探针和分析物的分子识别机理及信号转换机制，并研究检测环境对探针特异性、灵敏性及稳定性的影响。在此基础上优化和筛选出高效、稳定的探针，为食品安全中芳（杂）环类农兽药残留的快速、灵敏、稳定、高选择性的检测方法提供科学依据。

农兽药残留问题已成为食品安全中较为突出的问题，对此进行有效的监测显得非常重要。目前食品中农兽药残留的基本检测方法中色谱法具有较高的准确率、灵敏度和精密度，但存在操作费时、成本较高等缺点；免疫分析法具有快速、高通量等优点，但假阳性高、重复性差。本项目结合超分子化学、纳米科学和分析化学，创新性地提出了一种利用环糊精空腔的识别能力和量子点优良的光学性质，采用温和的偶联方法制备成量子点探针，检测杂环农药残留的新方法。本项目引入分子设计理念，利用环糊精具有高效的分子识别能力的特性，采用配体交换“一步法”将两亲性环糊精组装到量子点表面，制备出兼具量子点荧光特性及环糊精多分子识别能力的探针。同时，采用量子化学和结构化学的理论和方法，从分子角度解析探针和分析物的分子识别机理及信号转换机制，并研究检测环境对探针特异性、灵敏性及稳定性的影响。在此基础上优化和筛选出高效、稳定的探针，为食品安全中芳环类农兽药残留的快速、灵敏、稳定、高选择性的检测方法提供科学依据，并为其他生物分子的检测也提供了参考。