Molecularly imprinted polymers (MIPs) may be used to confer specific recognition properties to a variety of practical sensors and sorbents. However, the synthetic parameters (monomer species, template/monomer ratio, etc.) used to generate MIPs significantly impact their sensitivity and selectivity, generally requiring arduous empirical optimization to obtain materials with maximal target affinity. We present a MIP synthesis strategy that prioritizes the optimization of the pre-polymerization complex as a predictive model for the final polymer properties and demonstrate how greater target affinity may be obtained without iterative analysis of the polymer film. 2,4-Dichlorophenoxyacetic acid (2,4-D), a prevalent herbicide, was chosen for detection using electrogenerated molecularly imprinted polymers (eMIPs). eMIPs were rationally designed using molecular simulations to down-select an ideal functional monomer with a maximal affinity for 2,4-D. Following monomer selection, proton-based nuclear magnetic resonance (¹H NMR) titrations were used to verify the simulation results and optimize the monomer/2,4-D ratio by tracking the chemical shift associated with monomer/target binding. Following optimization, eMIPs were synthesized by the anodic electropolymerization of the selected monomer, o-phenylenediamine, onto gold substrates in the presence of 2,4-D, which was subsequently stripped away via solvent washing to reveal 2,4-D-specific binding sites. Surface sites were blocked upon 2,4-D association with the eMIP when placed in contaminated water, which was tracked electrochemically. The ability of molecular simulations and ¹H NMR titrations to predict optimal monomer/2,4-D ratios was evaluated by fitting the experimental data to a Langmuir–Freundlich isotherm, revealing a significant increase in target affinity (K_a) and binding site homogeneity (m) related to the chemical shifts exhibited by the pre-polymerization complex for o-phenylenediamine (o-PD). The two techniques, when evaluated on o-PD, predicted ideal monomer/template ratios with remarkable agreement. Thus, the synthetic strategy outlined herein represents a streamlined approach for the rapid prototyping and design of eMIP-based sensing elements essential for the realization of next-generation polymeric sensors and sorbents.

中文翻译：

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电生分子印迹聚合物 (eMIP) 的合理设计：最大化单体/模板亲和力

分子印迹聚合物 (MIP) 可用于为各种实用的传感器和吸附剂赋予特定的识别特性。然而，用于生成 MIP 的合成参数（单体种类、模板/单体比率等）会显着影响其灵敏度和选择性，通常需要艰苦的经验优化才能获得具有最大目标亲和力的材料。我们提出了一种 MIP 合成策略，该策略优先考虑预聚合复合物的优化作为最终聚合物特性的预测模型，并展示了如何在不对聚合物膜进行迭代分析的情况下获得更大的目标亲和力。选择 2,4-二氯苯氧基乙酸 (2,4-D) 是一种流行的除草剂，用于使用电生成的分子印迹聚合物 (eMIP) 进行检测。eMIP 是使用分子模拟合理设计的，以向下选择对 2,4-D 具有最大亲和力的理想功能单体。在单体选择之后，基于质子的核磁共振（¹ H NMR) 滴定用于验证模拟结果并通过跟踪与单体/目标结合相关的化学位移来优化单体/2,4-D 比率。优化后，在 2,4-D 存在下，通过所选单体邻苯二胺在金基材上的阳极电聚合合成 eMIP ，随后通过溶剂洗涤将其剥离以显示 2,4-D 特异性结合网站。当放置在受污染的水中时，表面位点与 eMIP 的 2,4-D 关联被阻断，这是电化学跟踪的。分子模拟的能力和¹通过将实验数据拟合到 Langmuir-Freundlich 等温线来评估 H NMR 滴定以预测最佳单体/2,4-D 比率，揭示了与化学物质相关的目标亲和力 ( K _a ) 和结合位点均匀性 ( m )的显着增加由预聚合复合物表现出位移为ö苯二胺（ø -PD）。当对o -PD进行评估时，这两种技术预测了理想的单体/模板比率，并且具有显着的一致性。因此，本文概述的合成策略代表了一种基于 eMIP 的传感元件的快速原型制作和设计的简化方法，对于实现下一代聚合物传感器和吸附剂至关重要。