Preparation of l‐phenylalanine‐imprinted solid‐phase extraction sorbent by Pickering emulsion polymerization and the selective enrichment of l‐phenylalanine from human urine

Abstract

A novel l-phenylalanine molecularly imprinted solid-phase extraction sorbent was synthesized by the combination of Pickering emulsion polymerization and ion-pair dummy template imprinting. Compared to other polymerization methods, the molecularly imprinted polymers thus prepared exhibit a high specific surface, large pore diameter, and appropriate particle size. The key parameters for solid-phase extraction were optimized, and the result indicated that the molecularly imprinted polymer thus prepared exhibits a good recovery of 98.9% for l-phenylalanine. Under the optimized conditions of the procedure, an analytical method for l-phenylalanine was well established. By comparing the performance of the molecularly imprinted polymer and a commercial reverse-phase silica gel, the obtained molecularly imprinted polymer as an solid-phase extraction sorbent is more suitable, exhibiting high precision (relative standard deviation 3.2%, n = 4) and a low limit of detection (60.0 ± 1.9 nmol·L(-1) ) for the isolation of l-phenylalanine. Based on these results, the combination of the Pickering emulsion polymerization and ion-pair dummy template imprinting is effective for preparing selective solid-phase extraction sorbents for the separation of amino acids and organic acids from complex biological samples.

Designing and controlling the morphology of spherical molecularly imprinted polymers

“…Hydrophilic particles tend to form oilin-water emulsions while hydrophobic particles lead to the opposite situation. Until now, silica, [43][44][45][46][47][48][49][50][51][52][53] Fe 3 O 4 particles, [54][55][56][57][58][59] chitosan, [60][61][62] halloysite nanotubes, [54][55][56]63 Janus hydroxyapatite NPs, 64,65 BHb, 66 yeast, 67 lignin, 68 fluorescent NPs, 69 etc., were adopted to stabilize Pickering emulsions for preparation of MIPs. Different particles enjoy different advantages.…”

Molecularly Imprinted Materials for Selective Biological Recognition

“…For example, as shown in Figure C, a dummy template anine‐imprinted polymer (DMIPs) using vinyl‐SiO 2 microspheres as substrate was prepared via surface imprinting technique by Zhu et al A high performance liquid chromatography for the simultaneous determination of eighteen amino acids in tobacco was prepared using the resulting DMIPs as sorbents for solid phase extraction . In addition, the suitable “dummy” template could contribute to the improvement of specific selectivity for the target template . For example, as shown in Figure D, Li et al have prepared a novel l ‐Phe MIPs using 1‐butyl‐3‐vinylimidazolium α‐aminohydrocinnamic acid salt ([Vbim][Phe]) as dummy template.…”

Pickering emulsion-based molecular imprinting

“…在生物样本中, 基于Pickering乳液的分子印迹技术也展现出巨大潜 力. 例如, Yang等人 [20] [21] , 我们将近年来已发表的采用Pickering乳液聚 [22,23] 、荧光 [19] 、空心 分子印迹 [22,29] 等)方向发展; (2) 向制备能在复杂样品 体系(如河水 [37,38] 、血液 [39,45] 、尿液 [20,39] [53,54] ; 对于疏水性蛋白质分子, 目前还没有利用Pickering乳液聚合成功合成蛋白质印 迹的报道. 但疏水蛋白具有在亲水-疏水界面通过自 组装形成蛋白膜的重要特性, 自组装的蛋白质颗粒本 身能作为固体颗粒稳定剂制备界面印迹MIP材料 [55] .…”