In this study, a novel kind of pH-responsive, magnetic and core-shell structured molecularly imprinted polymer (pH-MMIPs) was synthesized for the selective recognition of sulfamethoxazole (SMX). It was synthesized by way of surface imprinting and free radical polymerization. The composition and structure of pH-MMIPs has magnetic nanoparticles as its core, a thin imprinted polymer layer as its shell using 2-(Dimethylamino) ethyl methacrylate and 4-vinylphenylbronic acid as the pH-sensitive monomers, and SMX as template molecule. Interestingly, the pH-MMIPs could control the capture/release process in the selective recognition and detection of SMX by changing the pH value. Evaluation of the property of pH-MMIPs through series of adsorption experiments showed that it has an adsorption capacity of 25.41 mg·g⁻¹ with a very rapid speed of magnetic separation. Additionally, it was successfully applied to selectively detect SMX in real milk samples, and the recoveries was in ranges of 89.7% and 98.2%. This study provides a new method and idea for the selective separation of SMX residue in food using molecularly imprinted polymers with pH- response and identification.

在这项研究中，新型的pH响应，磁性和核壳结构分子印迹聚合物（pH-MMIPs）合成用于选择性识别磺胺甲恶唑（SMX）。它是通过表面压印和自由基聚合反应合成的。pH-MMIPs的组成和结构以磁性纳米粒子为核心，以甲基丙烯酸2-（二甲基氨基）乙酯和4-乙烯基苯基溴酸为pH敏感单体，以SMX为模板分子的壳层为薄的印迹聚合物。有趣的是，pH-MMIPs可以通过更改pH值来控制SMX的选择性识别和检测中的捕获/释放过程。通过一系列吸附实验评价pH-MMIPs的性质，表明其吸附容量为25.41 mg·g ^-1磁分离速度非常快。此外，它已成功应用于选择性检测纯牛奶样品中的SMX，回收率在89.7％和98.2％之间。这项研究提供了一种新的方法和思想，可以使用具有pH响应和鉴定功能的分子印迹聚合物选择性分离食品中的SMX残留物。