典型农药残留的双重信号增强SPR免疫传感检测技术研究

Residual pesticides are used to be considered as one of the most important pollutants in environment and foods. Signal enhanced detecting technology with high sensitivity is exigently required, for the reason that target pollutants are usually contained by samples with complex matrix.The object of this research is to establish a double enhanced surface plasmon resonance (SPR) immunosensing system for rapid determination of typical pesticide residues (parathion, atrazine, ractopamine, etc.). The targets are separated and enriched by magnetic nanospheres-antibody conjugates which are also performed as the sensitive recognize element and primary signal enhanceing material. Membrane of high biocompatibility material (chitosan etc.) is prepared on SPR chip surface to immobilize the antigen and increase the stability of the modified sensor chip. Staphylococcal protein A (SPA) is introduced into the detecting system as a secondary signal enhanceing material. A immunoseneing system with double signal enhancement will be established, which can be used to detect trace amount pesticides in environment and food samples. The results of this research can be utilized in environment pollutants monitoring, food safety and bioengineering, and will promote the development of relative subject analyzing techniques. Furthermore, good potential theoretical values and technique applications will be accomplished.

农药残留是造成环境污染、危害食品安全的重要因素之一，加强环境中农药残留检测，有利于保障人民身体健康、促进相关产业健康发展。但农药残留样品往往基质复杂、含量极低，高灵敏检测技术联合信号放大技术是实现环境中痕量农药残留快速检测的重要手段。本研究拟以多种典型农药（对硫磷、阿特拉津、毒死蜱等）为靶标，以SPR传感器件为换能器，磁性纳米微球-抗体偶联物为前处理分离富集材料和一级传感信号增强元件，在传感器芯片表面制备高生物相容性的壳聚糖膜，以固定抗原并提高芯片贮存稳定性，同时在免疫检测体系中引入SPA作为二级放大传感元件，构建集分离、富集和检测于一体的磁性微球-SPA双重信号放大SPR免疫传感系统，实现环境和食品中农药残留的痕量检测。该项目研究成果可用于环境监测、食品安全和生物工程等领域，推动相关学科的分析检测技术发展，具有重要的理论意义和广阔的应用前景。

本项目分别引入免疫磁颗粒及金标二抗作为信号放大材料，建立了农兽药残留快速检测的SPR免疫传感技术和检测方法，初步实现了对农兽药残留灵敏、特异的定量分析，为建立SPR免疫传感检测技术平台奠定了基础。分别采用MUA自组装固定法与壳聚糖旋涂固定法在SPR芯片表面固化包被原，在此基础上，通过间接竞争法构建了SPR免疫传感检测技术。制备了氨基修饰的MNP，并将其与抗体偶联，获得免疫磁颗粒。分别在SPR传感检测系统中引入免疫磁颗粒与金标二抗作为信号放大材料，建立了信号放大的SPR免疫传感检测技术，明显改善了灵敏度和检测范围。经过实样加标回收实验及与HPLC方法的比对实验，证明所建立的传感检测技术具有灵敏、特异的特点，可初步用于实际样品中的农兽药残留分析，为农兽药残留的高灵敏检测提供了新方法，为环境与食品中有机小分子污染物残留检测平台的建立奠定了基础，具有广阔的应用前景。