基于三维纳米适配体传感器的蔬菜中有机磷农药多残留同步检测方法研究

It is of great significance to develop a high efficiency and reliable method for simultaneous and rapid detection of organophosphorus pesticide residues in vegetables. Aptamers are artificial functional oligonucleic acids that are screened and amplified in vitro. Their recognition characteristics are similar to those of antibodies, exhibiting excellent accuracy & repeatability, and high purity. The sensing analysis method based on aptamers is expected to be an effective method to detect pesticide residues. However, the stability and reproducibility of aptasensor is a bottleneck of its application and development. The reasons are that the recognition mechanism of pesticide and aptamer, and the interference mechanism of sample compositions are not clear. In this project, we are going to make good use of a stable three-dimensional nano-aptamer rigid structure with nanoparticle to study the spatial conformation of the nano-aptamers before and after incubating with pesticides, and to explore the recognition mechanism of three-dimensional nano-aptamers and pesticide in order to improve the stability of the sensor. The influence rule of different labeling methods on dissolution voltammetry will be studied and a new method for simultaneous detection of organophosphorus pesticide residues in vegetables will be established by using special elements to label the aptamers. It will clarify the main interfering factors affecting the specificity of the aptamer and reveal the influence rule of the interference factors on the sensor signal, and provide a theoretical guidance for the processing method of vegetable samples. This research will provide a theoretical guidance and technical support for the establishment of a rapid and simultaneous detection method of multiple pesticide residues with high-selectivity and high-sensitivity.

研究高效、可靠的蔬菜中有机磷农药多残留同步快速检测方法具有十分重要的意义。适配体是体外筛选和扩增获得的核酸序列，其识别特性与抗体相似，具有极好的准确性、重复性和很高的纯度。基于适配体的传感分析方法有望成为农药残留的有效检测手段，但稳定性、重现性仍然是限制其应用和发展的瓶颈，究其原因农药与适配体识别影响机制、样品成分干扰机理不明晰。本项目拟利用纳米颗粒组装性能稳定的三维纳米适配体刚性结构，研究适配体与农药作用前后的空间构象规律，探明三维纳米适配体与农药识别影响机制，提高传感器的稳定性。利用特殊元素标记适配体，研究不同标记方法对溶出伏安谱图的影响规律，构建有机磷农药多残留的同步检测新方法。阐明蔬菜成分对适配体识别造成干扰的主要因子，揭示不同干扰因子对传感器信号的影响规律，为蔬菜样品处理方法提供理论指导。以上研究为建立高特异性、高灵敏度的农药多残留同步快速检测技术发展奠定理论基础。

有机磷农药作为一种广谱且高效的杀虫剂而经常被用于保障蔬菜质量，但因其种类繁多、违规滥用，对食品安全、人体健康和环境保护等都造成了巨大的威胁，也导致对其残留的检测面临着严峻的挑战。利用适配体构建快速检测方法大多具有灵敏度高、方便携带、操作简单等优势，便于推广应用。但在多残留同步检测中，各靶标适配体链易相互缠绕，产生信号干扰。本项目主要探究靶标农药与适配体之间的识别影响机制、样品成分干扰机理，构建蔬菜中有机磷农药多残留同步检测新方法。通过对三维纳米适配体与农药识别影响机制的探索，实现了有针对性地对适配体进行修饰和再构造，为高灵敏、高特异性适配体传感器的制备提供技术支撑。研究不同标记方法对适配体识别性能的影响规律，并拓展讨论了重金属、电活性物质等多种标记材料的标记效果。基于上述研究，构建了基于三维纳米适配体传感器的有机磷农药多残留检测新方法。对蔬菜成分中可能对适配体识别造成干扰的主要因子进行了探究，揭示不同干扰因子对传感器信号的影响规律，建立了蔬菜样品处理方法，为蔬菜中有机磷农药多残留同步检测技术的发展提供了重要理论参考和技术指导。