In this work, a novel molecularly imprinted electrochemical sensor based on the amino-functionalized silica nanoparticles was built for the sensitive and selective detection of 2,4-dichlorophenoxyacetic acid (2,4-D). The hierarchical porous dendrimer-like silica nanoparticles (HPSNs-NH₂) were synthesized by an ethyl ether emulsion method. The selective molecularly imprinted polymers (MIP) was prepared on the HPSNs-NH₂ modified electrode via electropolymerization by using 2,4-D as the template and o-phenylenediamine (OPD) as the monomer. The porous structure of HPSNs-NH₂ reduced the diffusion limitations of the analytes, enhanced the accessibility and increased the surface area of the sensor, while the MIP layer offered the ability to recognize and quantify target 2,4-D by using ferro/ferricyanide as probes. Several significant experimental parameters on the analytical performance of the MIP/HPSNs-NH₂ sensor were explored and optimized. Under the optimized condition, the sensor displayed an appreciable selectivity over structurally related compounds and good sensitivity toward 2,4-D. The linear range of 2,4-D detection was from 1.00 × 10⁻¹⁰ to 2.50 × 10⁻⁸ M and the detection limit was down to 1.17 × 10^–11 M according to the 3S_a/b criteria. This method has been applied to detect 2,4-D in bean sprout samples with satisfying results.

在这项工作中，建立了一种基于氨基官能化二氧化硅纳米粒子的新型分子印迹电化学传感器，用于灵敏和选择性地检测2,4-二氯苯氧基乙酸（2,4-D）。通过乙醚乳液法合成了分层的多孔树状大分子状二氧化硅纳米粒子（HPSNs-NH ₂）。以2,4-D为模板，邻苯二胺（OPD）为单体，通过电聚合在HPSNs-NH ₂修饰电极上制备了选择性分子印迹聚合物（MIP）。HPSNs-NH ₂的多孔结构降低了分析物的扩散限制，增强了可及性并增加了传感器的表面积，而MIP层则提供了通过使用铁/铁氰化物作为探针来识别和量化目标2,4-D的能力。探索和优化了MIP / HPSNs-NH ₂传感器分析性能的几个重要实验参数。在优化的条件下，该传感器对结构相关的化合物具有明显的选择性，并且对2,4-D具有良好的敏感性。2,3-D检测的线性范围从1.00×10 ^-10到2.50×10 ^-8  M，检测极限 根据3S _a降低到1.17×10 ^–11 M/ b标准。该方法已用于豆芽样品中2，4-D的检测，结果令人满意。