阵列式微流控纸芯片的农药残留比率荧光可视化检测方法

Due to the excess pesticide residues remain do great harm to the health of human and the limitation of current detection methods for pesticide residues, this project proposed a simple and rapid sensing method for the visual and fluorescent detection of pesticide residues on ratiometric fluorescent quantum dots on an arraying paper-based microfluidic chip. Firstly, the excellent optical performance and good stability of the gold nanoparticles and the ratiometric fluorescent have been prepared. Further, during the pesticide residue detection, the mechanism of action on the dispersity of the gold nanoparticles, the interactions among the various substance, and the response of the fluorescence will be researched. The appetency’s difference and proposed compensation method between different pesticides and aptamers should be researched, and fluorescent signal’s perception model of residual pesticides will be established. For the arraying paper-based microfluidic chip, flowing-mixing characteristics of reagents on paper-based chip under micro scale and the relationship between air permeability, surface micromorphology and mixedness will be studied through PIV and surface profilometer. Resisting reverse-flow’s mechanism and resisting flow’s performance of one-way flowing structure will be analyzing. Optimal mixed structure, paper material and parameters of one-way flowing structure should be determined. Then structure of arraying paper-based chip will be designed and the sensor of arraying paper-based microfluidic chip based on ratiometric fluorescence and aptamers will be established. Lastly, the testing of detecting pesticide residues through fluorescent visualization should be conducted. By this subject research, it will be to break through the problem of detecting many pesticides through visual method with rapid speed, simple step, low cost, high sensitivity.

针对蔬果中农药残留量超标危害人类健康，而现有检测方法存在诸多不足的问题，本项目提出阵列式微流控纸芯片的农药残留比率荧光可视化检测方法。研究制备具有光学性能和稳定性好的金纳米粒子和比率荧光探针，探明农药残留检测反应过程的金纳米粒子“团聚-分散-团聚”作用机制、多物质之间的作用关系、荧光响应规律，研究不同农药与适配体之间的结合亲和力差异性以及误差补偿方法，建立农药残留荧光信号感知模型；借助粒子图像测速仪、表面形貌仪等研究微尺度下多种试剂在纸芯片上的流动与混合特性、纸质的透气度和表面微粗糙形貌与混合度的对应关系，分析单向流动结构的逆向阻流作用机制及阻流性能，确定最优的混合结构、纸质材料和阻流结构参数；设计阵列纸芯片结构，构建基于比率荧光探针耦合核酸适配体的阵列式微流控纸芯片传感器，进行农药残留荧光可视化检测验证试验。本项目将突破快速、简便、低成本、高灵敏度、多种农药可视化检测的难题。

针对蔬果中农药残留量超标危害人类健康，而现有检测方法存在诸多不足的问题，本项目提出了基于比率荧光探针的阵列式微流控纸芯片的农药残留检测方法。深入研究了金纳米粒子和比率荧光探针的制备方法；探明了金纳米粒子团聚效应、多种试剂和物质之间的作用关系、目标农药分子浓度的荧光响应规律，建立了基于比率荧光探针和适配体的农药残留荧光信号感知方法；建立了纸芯片上流动数学模型、不同纸质芯片的混合模型，研究了微混合结构、通道内肋和阻流结构、三维多层纸芯片设计及混合性能，探明了阻流和混合作用机制，确定了最优混合结构和纸芯片参数；构建了基于比率荧光探针-金纳米粒子耦合核酸适配体的三维阵列式微流控纸芯片，设计了可以同时检测九组样品中不同农药的纸芯片检测装置，实现了蔬菜农药残留的可视化检测；利用石墨烯量子点优异的光/电化学性质，构建了基于石墨烯量子点/三联吡啶钌电化学发光的农药残留传感器、基于信号双放大-双抑制原理的农药残留光电化学传感器、以及基于信号“开-关-开”原理的适配体农药残留光电化学传感器，并利用标准加入法对果蔬中的农药残留含量进行了测定，研究表明，上述所制备的传感器均实现了对农药残留的灵敏、选择性检测，且均具有优异的重现性和较好的稳定性。本项目突破了快速、简便、低成本、高灵敏度、多种农药可视化检测的难题。