Recent Advances in Molecularly Imprinted Polymers for Antibiotic Analysis

The abuse and residues of antibiotics have a great impact on the environment and organisms, and their determination has become very important. Due to their low contents, varieties and complex matrices, effective recognition, separation and enrichment are usually required prior to determination. Molecularly imprinted polymers (MIPs), a kind of highly selective polymer prepared via molecular imprinting technology (MIT), are used widely in the analytical detection of antibiotics, as adsorbents of solid-phase extraction (SPE) and as recognition elements of sensors. Herein, recent advances in MIPs for antibiotic residue analysis are reviewed. Firstly, several new preparation techniques of MIPs for detecting antibiotics are briefly introduced, including surface imprinting, nanoimprinting, living/controlled radical polymerization, and multi-template imprinting, multi-functional monomer imprinting and dummy template imprinting. Secondly, several SPE modes based on MIPs are summarized, namely packed SPE, magnetic SPE, dispersive SPE, matrix solid-phase dispersive extraction, solid-phase microextraction, stir-bar sorptive extraction and pipette-tip SPE. Thirdly, the basic principles of MIP-based sensors and three sensing modes, including electrochemical sensing, optical sensing and mass sensing, are also outlined. Fourthly, the research progress on molecularly imprinted SPEs (MISPEs) and MIP-based electrochemical/optical/mass sensors for the detection of various antibiotic residues in environmental and food samples since 2018 are comprehensively reviewed, including sulfonamides, quinolones, β-lactams and so on. Finally, the preparation and application prospects of MIPs for detecting antibiotics are outlined.     

扑热息痛分子印迹聚合物应用于固相萃取的研究

以扑热息痛为印迹分子,丙烯酰胺为功能单体,乙二醇二甲基丙烯酸酯为交联剂合成了棒状的印迹聚合物;把其装于自制的固相萃取柱中,研究了以乙腈和水为溶剂时扑热息痛在柱上的保留行为;通过优化清洗、洗脱条件,使扑热息痛和与其具有相似结构的非那西丁、对叔丁基苯酚在柱上得到了很好的分离;同时也测定了治疗感冒的药物海王银得菲中扑热息痛的含量,其回收率可达94．3％．     

Application of Molecularly Imprinted Polymers in the Analysis of Waters and Wastewaters

The increase of the global population and shortage of renewable water resources urges the development of possible remedies to improve the quality and reusability of waste and contaminated water supplies. Different water pollutants, such as heavy metals, dyes, pesticides, endocrine disrupting compounds (EDCs), and pharmaceuticals, are produced through continuous technical and industrial developments that are emerging with the increasing population. Molecularly imprinted polymers (MIPs) represent a class of synthetic receptors that can be produced from different types of polymerization reactions between a target template and functional monomer(s), having functional groups specifically interacting with the template; such interactions can be tailored according to the purpose of designing the polymer and based on the nature of the target compounds. The removal of the template using suitable knocking out agents renders a recognition cavity that can specifically rebind to the target template which is the main mechanism of the applicability of MIPs in electrochemical sensors and as solid phase extraction sorbents. MIPs have unique properties in terms of stability, selectivity, and resistance to acids and bases besides being of low cost and simple to prepare; thus, they are excellent materials to be used for water analysis. The current review represents the different applications of MIPs in the past five years for the detection of different classes of water and wastewater contaminants and possible approaches for future applications.     

沉淀聚合法合成拟除虫菊酯类分子印迹聚合物及其吸附性能研究

采用沉淀聚合法,以拟除虫菊酯的结构类似物二苯醚-联苯共晶作为替代模板,优化得到最佳的拟除虫菊酯类分子印迹聚合物合成条件:模板分子(二苯醚-联苯共晶)、功能单体(4-乙烯吡啶)、交联剂(乙二醇二甲基丙烯酸酯)的摩尔比为1∶6∶20,反应温度为70℃,引发剂用量为1%。将合成的分子印迹聚合物通过扫描电镜进行表征,并对吸附性能进行测试,其对60μg·mL~(-1)的二苯醚-联苯共晶的最大吸附量为6 041μg·g~(-1),且在7 h后达到吸附平衡。通过选择性实验得到印迹聚合物对毒死蜱、联苯菊酯、甲氰菊酯、氯菊酯、氯氰菊酯、氰戊菊酯的吸附量分别为259、316、311、271、305、298μg·g~(-1),而非印迹聚合物的吸附量则为169、188、181、183、151、142μg·g~(-1),印迹聚合物的选择性能明显高于非印迹聚合物。     

Synthesis and Characterization of Molecularly Imprinted Nanoparticle Polymers for Selective Separation of Anthracene

Two anthracene molecularly imprinted nanoparticle polymers namely; An–MINP1 and An–MINP2, were synthesized using the precipitation polymerization method. An–MINPs were used for selective separation of anthracene from aqueous solutions. The data revealed that the maximum binding capacity of An–MINPs for anthracene were 320.8 and 374.3 mg g^?1 for An–MINP1 and An–MIPN2, respectively, compared with 2.8 and 4 µg g^?1 obtained by using their corresponding non-imprinted polymers NIP1 and NIP2, respectively. Under optimized conditions, An–MINPs give high selectivity and sensitivity of anthracene separation. The anthracene uptake percentage from aqueous solutions ranged from 90.3 to 99.9%.     

Magnetic Core-Shell Nanoparticles Using Molecularly Imprinted Polymers for Zearalenone Determination

This paper describes the synthesis of novel molecularly imprinted magnetic nano-beads for the selective extraction (MISPE) of zearalenone mycotoxin in river and tap waters and further analysis by high-performance liquid chromatography (HPLC) with fluorescence detection (FLD). A semi-covalent imprinting approach was achieved for the synthesis of the molecularly imprinted polymers (MIP). The nanoparticles were prepared by covering the starting Fe₃O₄ material with a first layer of tetraethyl orthosilicate (TEOS) and then with a second layer using cyclododecyl 2-hydroxy-4-(3-triethoxysilylpropylcarbamoyloxy) benzoate. The last was used with a dual role, template and functional monomer after the extraction of the template molecule. The material was characterized by transmission electron microscopy (TEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopies (FT-IR). The solid phase extraction was optimized in all the steps: loading, washing and elution. The optimal conditions allowed the determination of zearalenone in trace levels of 12.5, 25 and 50 µg L⁻¹ without significant differences between the fortified and found level concentrations.     

羟丙哌嗪分子印迹的固相萃取

以L-羟丙哌嗪为模板分子, α-甲基丙烯酸为功能单体, 三羟甲基丙烷三甲基丙烯酸酯为交联剂, 合成了羟丙哌嗪分子印迹聚合物, 利用该聚合物进行羟丙哌嗪固相萃取应用研究. 实验证明, 所合成的分子印迹聚合物具有良好的识别萃取模板分子羟丙哌嗪的能力, 能够用于羟丙哌嗪的富集浓缩, 而空白聚合物却不具备这样的特性. 考察了模板分子与其结构类似物苄基哌嗪、N-异丙基哌嗪和乙氧基羰基哌嗪的固相萃取分离情况, 研究表明, 虽然其中的苄基哌嗪在印迹材料上具有最强的保留, 但是通过先后使用不同的洗脱溶液实现了模板分子与苄基哌嗪的选择性分离.探讨了印迹识别机理,并用PM3 半经验计算机模拟方法进行了辅助分析验证.     

The Ultratrace Determination of Fluoroquinolones in River Water Samples by an Online Solid-Phase Extraction Method Using a Molecularly Imprinted Polymer as a Selective Sorbent

Fluoroquinolones (FQs) are broad-spectrum antibiotics widely used to treat animal and human infections. The use of FQs in these activities has increased the presence of antibiotics in wastewater and food, triggering antimicrobial resistance, which has severe consequences for human health. The detection of antibiotics residues in water and food samples has attracted much attention. Herein, we report the development of a highly sensitive online solid-phase extraction methodology based on a selective molecularly imprinted polymer (MIP) and fluorescent detection (HPLC-FLD) for the determination of FQs in water at low ng L⁻¹ level concentration. Under the optimal conditions, good linearity was obtained ranging from 0.7 to 666 ng L⁻¹ for 7 FQs, achieving limits of detection (LOD) in the low ng L⁻¹ level and excellent precision. Recoveries ranged between 54 and 118% (RSD < 17%) for all the FQs tested. The method was applied to determining FQs in river water. These results demonstrated that the developed method is highly sensitive and selective.     

核-壳型分子印迹聚合物的制备与应用

分子印迹聚合物是具有与模板分子形状、大小及官能团完全匹配的特异识别位点的高分子聚合物,能选择性识别、有效富集目标分析物(模板分子)并去除干扰物,已广泛应用于样品前处理、化学/生物传感、药物输送等领域.然而,在合成过程中,仍存在模板分子洗脱困难、有效识别位点少、结合容量低、传质速率慢等问题.核-壳型分子印迹聚合物即在核层颗粒表面进行分子印迹,即表面印迹,印迹位点仅存在于壳层结构中,利于模板分子洗脱及扩散,能够增加有效识别位点并提高印迹容量.依据核层材料的不同,本文详细介绍了以磁性材料及非磁性材料为核的核-壳型分子印迹聚合物的合成与应用,探讨了中空核-壳分子印迹聚合物的制备与发展,并对核-壳印迹聚合物的发展前景进行了展望.     

分子印迹聚合物微球的制备及应用研究进展

球形分子印迹聚合物具有制备简单、使用方便；分子识别效率高且便于功能设计等优点，近年来成为分子印迹技术领域研究的热点之一。对球形分子印迹聚合物微球的制备及其应用研究进展作了较为详细的介绍。     

Selective Preconcentration of Mezlocillin from Eggs by Molecularly Imprinted Polymers on Silica

Surface molecularly imprinted polymers for mezlocillin were used for the selective solid-phase extraction of mezlocillin from eggs. The molecularly imprinted polymers were prepared using mezlocillin as the template, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, silica particle as the support and were characterized by infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorption properties of polymers were investigated in detail. The obtained polymers provided high imprinting efficiency to mezlocillin with an imprinting factor of 3.72 and were used as selective sorbents for mezlocillin. Molecularly imprinted solid-phase extraction followed by high-performance liquid chromatography was used for the determination of mezlocillin in eggs and the conditions were evaluated. The average recovery of mezlocillin in fortified eggs was between 69.8 and 82.3% with a relative standard deviation less than 6.9%. The results demonstrate the application of molecularly imprinted polymers for the extraction of mezlocillin from biological samples.     

Efficient Separation of Hydrophobic Molecules by Molecularly Imprinted Cyclodextrin Polymers

Cyclodextrins were cross-linked with toluene 2,4-diisocyanate in dimethyl sufoxide in the presence of hydrophobic biomolecules as templates, and the imprinted polymers were applied to the stationary phases of high performance liquid chromatography. Molecular imprinting efficiently promoted the binding-affinity and substrate-selectivity towards the template molecule, compared with the control polymers prepared in their absence. When cholesterol (template molecule) was complexed with cyclodextrins prior to the polymerization, for example, the imprinted polymer retained cholesterol more strongly than other steroids. Upon the polymerization without a template molecule, the binding towards steroids was much weaker. Besides steroids, imprinting was effective for various hydrophobic and rigid template molecules. Since binding of the guest molecule was based on inclusion complex formation with cyclodextrins, separation could be achieved in the solvents containing water. These polymeric receptors are also applicable to selective recognition of biologically important molecules or removal of toxic molecules from aqueous media. Thus, imprinting of cyclodextrins is useful for the preparation of synthetic tailor-made receptors for various kinds of hydrophobic guest molecules.     

除草剂青莠定分子印迹聚合物的合成及结合性能研究

采用分子印迹技术,分别以α-甲基丙烯酸和4-乙烯基吡啶为功能单体,合成了两种对除草剂青莠定具有选择性结合能力的分子印迹聚合物．紫外光度法研究显示了模板分子青莠定和4-乙烯基吡啶的离子作用强于它和α-甲基丙烯酸之间的氢键作用,并用平衡结合实验研究了不同功能单体的聚合物对模板分子的结合能力和对底物的选择性,结果表明以4-乙烯基吡啶为功能单体合成的分子印迹聚合物对青莠定表现出更高的结合能力和更优的选择性．这对分子印迹技术用于环境样品中除草剂青莠定的分离和富集具有重要意义。     

邻香草醛分子印迹聚合物膜的制备及其透过选择性质的研究

采用紫外光引发原位聚合的方法制备了具有支撑膜的邻香草醛分子印迹聚合物膜. 紫外光度法测定了模板分子和功能单体之间的结合常数和化学计量比(n＝2). 用傅立叶红外光谱和扫描电镜分别测定了膜的结构和表面形貌; 膜渗透实验结果表明在干扰物存在时印迹膜对模板分子表现出良好的选择透过性能. 研究了分子印迹聚合物膜透过的机理、并为分子印迹技术应用于传感器领域增加了理论和实验方法.     

分子烙印固相萃取技术在环境样品分析中的应用

分子烙印固相萃取技术克服了传统固相萃取技术选择性差的缺陷,实现了对复杂样品中特定分析对象或杂质的选择性提取,从而大大提高了分析测试的精度和准确性,并降低了检测限。该文对分子烙印聚合物(MIPs)作为固相萃取填料从复杂的环境样品中分离、富集和纯化微量及痕量的目标化合物进行了综述,涉及的目标化合物包括杀虫剂、除草剂、兽药等各类农药残留以及重金属离子和某些生物毒素等。     

一种高选择性固相萃取吸附剂--分子印迹聚合物

固相萃取是对样品富集、分离的一种有效方法,因而得到广泛应用.分子印迹是近些年发展起来的新技术,由于分子印迹聚合物具有高的选择性,被应用于环境、药物、生物、食品等样品的分析.本文介绍了固相萃取和分子印迹技术的原理以及两者结合用于固相萃取的过程,对近10年来国内外分子印迹聚合物应用于固相萃取的研究工作进行了总结和评述,并对其将来的发展进行了展望.     

替代模板分子印迹技术在样品前处理中的应用

分子印迹聚合物具有抗恶劣环境、选择性高、稳定性好等特点,广泛应用于复杂样品的前处理。采用结构类似物作为替代模板分子,可以解决分子印迹聚合物制备时目标物溶解性差的问题,替代模板分子印迹聚合物不仅对目标分析物具有选择性识别能力,还可以避免模板泄露对痕量分析造成的影响。本文综述了替代模板分子印迹技术在样品前处理中的应用进展,包括替代模板分子印迹技术在固相萃取、固相微萃取、色谱固定相、基质固相分散萃取中的应用,最后对替代模板分子印迹技术在未来的样品前处理中的研究进行了展望。     

大黄酸磁性印迹聚合物的制备及其应用研究

以SiO2包覆的磁性粒子为载体,大黄酸为模板分子,苯基和氨基硅烷偶联剂为二元功能单体,正硅酸乙酯为交联剂制备大黄酸磁性印迹聚合物。采用红外光谱和扫描电镜对该印迹聚合物进行表征。结果表明,该印迹聚合物颗粒分散均匀,呈立方体结构,印迹壳层厚度约75～100nm。结合磁固相萃取技术和高效液相色谱技术对大黄蒽醌类组分进行富集分离,实现猕猴桃根提取液中大黄酸、大黄素、大黄酚和大黄素甲醚等组分的同时分离、富集和检测。     

高岭土磁性复合材料表面印迹聚合物选择性吸附分离环丙沙星

以氨基改性的磁性高岭土为基质材料,利用电子转移产生催化剂的原子转移自由基聚合法制备磁性高岭土表面印迹聚合物（MMIPs）。通过FTIR、TEM、TGA、XRD和VSM等方法对其物理化学性质进行表征,其比表面积112 m²·g^-1,且具有较好的热稳定性、超顺磁性（M_s=13.365 emu·g^-1）。吸附性能研究表明,准二级动力学模型能较好地描述MMIPs对环丙沙星（CIP）吸附动力学行为,Langmuir等温模型能较好地拟合MMIPs对CIP的吸附平衡数据,25℃时MMIPs的单分子层吸附容量为89.36 mg·g^-1。选择性实验研究表明,MMIPs对CIP具有较好地选择识别性。结合高效液相色谱分析技术,MMIPs已成功应用于鲜鱼样品中痕量CIP的分离、富集和回收,CIP的回收率为92.15%。     

高岭土磁性复合材料表面印迹聚合物选择性吸附分离环丙沙星

以氨基改性的磁性高岭土为基质材料,利用电子转移产生催化剂的原子转移自由基聚合法制备磁性高岭土表面印迹聚合物(MMIPs)。通过FTIR、TEM、TGA、XRD和VSM等方法对其物理化学性质进行表征,其比表面积112 m2·g-1,且具有较好的热稳定性、超顺磁性(Ms=13.365 emu·g-1)。吸附性能研究表明,准二级动力学模型能较好地描述MMIPs对环丙沙星(CIP)吸附动力学行为,Langmuir等温模型能较好地拟合MMIPs对CIP的吸附平衡数据,25℃时MMIPs的单分子层吸附容量为89.36 mg·g-1。选择性实验研究表明,MMIPs对CIP具有较好地选择识别性。结合高效液相色谱分析技术,MMIPs已成功应用于鲜鱼样品中痕量CIP的分离、富集和回收,CIP的回收率为92.15%。