分子印记识别与磁性粒子类酶催化结合的选择性化学发光分析

Chemiluminescence (CL) owns some unique advantages including high sensitivity, simplicity, low cost of instrumentation and maintenance, and hence has been used in quite diverse fields such as medical diagnostics, chemical/biological analysis, environmental monitoring and food safety. The traditional CL systems usually use enzyme to catalyzedly enhance CL intensity, and use antibody to improve the selectivity. However, these biological materials have some disadvantages such as poor stability, limited kinds and high cost, which limit the further development and popularization of CL assay. In this proposal, aiming at the above needs and difficulties, our strategy is to develop a selective CL system by a cooperative approach of nanotechnology, nano catalysis and molecular imprinting. Based on the molecular structure of the organophosphorus pesticides, we will explore the principle and method to molecular imprinting at surface of magnetic nanoparticles and in the matrix of magnetic nanoparticles, for preparing magnetic nanoprobes with high dense imprinted sites. Through the amplifying of CL signal by the peroxidase-like catalysis of magnetic nanoparticles and the selective binding of target molecules in the imprinted sites, the qualitative and quantitative analysis will be realized for untrasensitive detection of target pesticides. After studying sensitivity, selectivity and reliability to the different pesticide molecules, the nanoprobes with different sensitivity will further be assembled into array to develop the high-throughput sensor for detecting pesticide residues. The obtained results in this project will provide new theoretical basis and technical fundament for developing selective, high integrated and miniaturized CL sensors.

化学发光分析以其灵敏度高、设备简单等优点，广泛应用在医学诊断、生化分析、环境监测及食品安全等领域。经典的化学发光体系普遍使用酶催化提高发光效率，用抗体识别目标种。然而生物材料性质不稳定、来源有限且价格昂贵，严重阻碍发光分析的发展和普及。针对上述难题，本研究项目拟运用纳米合成、纳米催化特性和仿生分子印记手段，发展新的选择性化学发光体系及其分析方法。重点针对有机磷农药分子结构特点，探索磁性纳米粒子表面和之间的分子印记新方法，设计制备具有高密度分子识别位点的磁性纳米探针。借助磁性粒子对化学发光的类酶催化增强效应和印记位点对目标分子的特异捕获能力，实现对目标种定性定量的超敏感分析。在验证对不同农残检测灵敏性、选择性和可靠性的基础上，建立不同印记磁性探针阵列组装的方法，结合成像分析，发展高通量的农残快速检测传感器，为未来高选择性、高度集成化和微型化的化学发光传感器件提供理论基础和技术储备。

本项目以目前社会公众高度关注的农药残留和重金属离子污染的快速检测为目标牵引，发展了基于化学发光及荧光纳米探针的传感检测技术，实现了对多种农残的快速痕量检测，以及重金属离子的可视化定量识别。主要发现点和成果如下：（1）筛选和制备了多种高效的化学发光及荧光纳米敏感材料如上转换纳米材料，多色发光碳材料等；（2）结合纳米敏感材料对农残及重金属离子的选择性富集与快速敏感识别，建立了高选择性、高敏感性的纳米光学传感原理与实现途径；（3）提出了几种新颖的纳米荧光开关设计原理和制备方法，在此基础上制备了剂量敏感的荧光宽色度比色试纸，实现了对复杂环境中农残和重金属离子的可视化定量分析检测。上述研究工作取得了多项具有创新性和系统性的研究成果，部分研究成果已经在国际期刊J. Am. Chem. Soc.，Angew. Chem. Int. Ed.，Anal. Chem.，J. Phys. Chem. C.，Nanoscle，Biosens. Bioelectron.，RSC Adv.，Analyst和Anal. Chim. Acta上共发表SCI 论文14 篇。