A New Mechanistic Diagram for Molecularly Imprinted Polymers

2003 ◽  
Vol 787 ◽  
Author(s):  
David A. Spivak

ABSTRACTA new mechanistic diagram describing the non-covalent molecular imprinting process is put forth in the text. A significant consequence of the new mechanistic picture is that the pre-polymer complex structure does not necessarily reflect the structure of the final binding sites in the polymer. Two independent studies are presented in combined form that support the suggested changes to the mechanistic diagram. In the first study, the maximum number of functional groups surrounding the template molecule in solution are shown to be less than the average number of functional groups in the binding sites of the polymers. In the second study, shape selectivity is shown to be an important contributor to molecular recognition by the imprinted polymers; which is significant because contributions of shape cannot be predicted by the solution phase pre-polymer complex.

2011 ◽  
Vol 306-307 ◽  
pp. 638-641 ◽  
Author(s):  
Fu Guang Lu ◽  
Yu Lei Xi ◽  
Zhen Lv ◽  
Lu Lu Fan ◽  
Hua Min Qiu ◽  
...  

Molecular imprinting technology was employed to produce one kind of Phenylalanine ( Phe) molecularly imprinted polymers (MIP)by precipitation polymerization using Phe, anhydrous alcohol, acrylamide, ethylene glycol dimethacrylate, and azobisisobutyronitrile as template, porogen, functional monomer, cross-linker and initiator respectively. In this study, the polymerization conditions were optimized. The template on particle size and morphology of polymers were investigated in detail by scanning electron microscopy (SEM) and adsorption isotherm determination. The binding properties of Phe on imprinted polymers were evaluated in water by equilibrium rebinding experiments, and the maximum number of adsorption was 0.60 mmol/g. It is indicated that the existence of binding sites in imprinted polymers was proved and the binding sites showed good specific and selective capability to the template molecule Phe. So the polymers would be used to separate Phe from medicine and food.


e-Polymers ◽  
2009 ◽  
Vol 9 (1) ◽  
Author(s):  
Manuela Curcio ◽  
Ortensia Ilaria Parisi ◽  
Giuseppe Cirillo ◽  
Umile Gianfranco Spizzirri ◽  
Francesco Puoci ◽  
...  

AbstractThe aim of this study is the preparation of molecularly imprinted polymers with high selectivity for metotrexate (MTX), a useful antineoplastic drug widely employed in clinical trials. Methacrylic acid, 2-(dimethylamino)ethyl methacrylate and a mixture of them were tested as functional monomers in order to optimize the performance of imprinted materials. The specificity and the selectivity of imprinted polymers was tested by performing rebinding experiments in water at pH 7.4. The best results were obtained by employing both functional monomers in the polymeric feed. In this way, each monomer interacts with complementary functionalities on template molecule, stabilizing the prepolymerization complex and minimizing the repulsive effects (due to the ionization of functional groups) in the rebinding media.


Sensors ◽  
2021 ◽  
Vol 21 (8) ◽  
pp. 2757
Author(s):  
W. Rudolf Seitz ◽  
Casey J. Grenier ◽  
John R. Csoros ◽  
Rongfang Yang ◽  
Tianyu Ren

This perspective presents an overview of approaches to the preparation of molecular recognition agents for chemical sensing. These approaches include chemical synthesis, using catalysts from biological systems, partitioning, aptamers, antibodies and molecularly imprinted polymers. The latter three approaches are general in that they can be applied with a large number of analytes, both proteins and smaller molecules like drugs and hormones. Aptamers and antibodies bind analytes rapidly while molecularly imprinted polymers bind much more slowly. Most molecularly imprinted polymers, formed by polymerizing in the presence of a template, contain a high level of covalent crosslinker that causes the polymer to form a separate phase. This results in a material that is rigid with low affinity for analyte and slow binding kinetics. Our approach to templating is to use predominantly or exclusively noncovalent crosslinks. This results in soluble templated polymers that bind analyte rapidly with high affinity. The biggest challenge of this approach is that the chains are tangled when the templated polymer is dissolved in water, blocking access to binding sites.


RSC Advances ◽  
2018 ◽  
Vol 8 (1) ◽  
pp. 311-327 ◽  
Author(s):  
Xi Wu ◽  
Jiajun Du ◽  
Mengyao Li ◽  
Lintao Wu ◽  
Chun Han ◽  
...  

Molecularly imprinted polymers (MIPs) are tailor-made materials with special binding sites.


2014 ◽  
Vol 955-959 ◽  
pp. 239-242
Author(s):  
Ping Geng ◽  
Qing Shan Liu ◽  
Kebaituli Gulibanumu ◽  
Xu Li ◽  
Ke Qin Li ◽  
...  

Molecularly imprinted polymers (MIPs) are synthetic materials that can be the environmental protection extraction method in TCM research and industry. They can overcome the defects of traditional extract methods and environmental pollution. In our research, MIPs were prepared by precipitation polymerization with neuro-protective picroside I and ginsenoside Rb1 as the template molecule. Moreover, the morphology of MIPs was characterized by electron microscope scanning and the static adsorption capacity was measured by the Scatchard equation. Finally, MIPs were made into MIP-SPE columns to enrich the template molecule and its analogues comparing with C18-SPE column and the results show that MIPs have good affinity and selectivity towards the Rb1 and Picroside I in SPE columns. This research may offer a more environmentally friendly method to extract active compounds in the traditional herbal.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ziqi Xie ◽  
Yunjing Luo ◽  
Zhen Na ◽  
Wei Zhang ◽  
Yufei Zong

AbstractIn this study, a novel method based on genistein magnetic molecularly imprinted polymers (Gen-MMIPs) was developed utilizing a surface molecular imprinting technique, in which genistein was used as the template molecule and Fe3O4 was used as the carrier. The synthesis of Gen-MMIPs was characterized by using scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which indicated that the diameter of the Gen-MMIPs was approximately 500 nm. Via analysis with a vibrating sample magnetometer (VSM), the saturation magnetization of Gen-MMIPs was determined to be 24.79 emu g−1. Fourier transform infrared (FT-IR) spectroscopy showed that polymer groups were on the surface of the magnetic carrier. Adsorption experiments suggested that the genistein adsorption capability of Gen-MMIPs was 5.81 mg g−1, and adsorption equilibrium was achieved within 20 min. Gen-MMIPs as dispersive solid-phase extraction (dSPE) adsorbents combined with HPLC were used to selectively separate genistein in soy sauce samples, and the recoveries ranged from 85.7 to 88.5% with relative standard deviations (RSDs) less than 5%, which proved that this method can be used for the detection of genistein residues in real samples.


2021 ◽  
Author(s):  
Ziqi Xie ◽  
Yunjing Luo ◽  
Zhen Na ◽  
Wei Zhang ◽  
Yunfei Zong

Abstract In this study, a novel method based on genistein magnetic molecularly imprinted polymers (Gen-MMIPs) was developed by surface molecular imprinting technique, in which genistein was used as the template molecule and Fe3O4 was used as the carrier. The synthesis of Gen-MMIPs were characterized by using of scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which indicated the diameters of Gen-MMIPs were about 500 nm. Through the technique of vibrating sample magnetometer (VSM), the saturation magnetization of Gen-MMIPs were detected as 24.79 emu/g. Fourier transform infrared (FR-IR) spectroscopy showed that polymer groups were on the surface of the magnetic carrier. Adsorption experiment suggested the adsorption capability of Gen-MMIPs to genistein were 1.55 mg/g, and 2 the adsorption equilibrium was achieved within 20 min. Gen-MMIPs as dispersive solid-phase extraction adsorbent combined with HPLC was used to selectively separate genistein in soy sauce samples, the recoveries were ranged from 85.7% to 88.5% with the relative standard deviations (RSD) less than 5%, which proved this method can be used for the detection of genistein residues in real samples.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Shanwen Zhao ◽  
Chanling Wei ◽  
Zhian Sun ◽  
Huachun Liu ◽  
Yanqiang Zhou ◽  
...  

Chloramphenicol- (CAP-) restricted access media-molecularly imprinted polymers (CAP-RAM-MIPs) were prepared by precipitation polymerization using CAP as a template molecule, 2-diethylaminoethyl methacrylate (DEAEM) as a functional monomer, ethylene glycol dimethyl acrylate (EDMA) as a crosslinking agent, glycidyl methacrylate (GMA) as an outer hydrophilic functional monomer, and acetonitrile as a pore former and solvent. The CAP-RAM-MIPs were successfully characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorption performance was investigated in detail using static, dynamic, and selective adsorption experiments. Adsorption equilibrium could be reached within 11 min. The CAP-RAM-MIPs had a high adsorption rate and good specific adsorption properties. Scatchard fitting curves indicated there were two binding sites for CAP-RAM-MIPs. Adsorption was Freundlich multilayer adsorption and consistent with the quasi-second kinetic model. Using CAP-RAM-MIPs for selective separation and enrichment CAP in bovine serum in combination with high-performance liquid chromatography (HPLC), CAP recovery ranged from 94.1 to 97.9% with relative standard deviations of 0.7–1.5%. This material has broad application prospects in enrichment and separation.


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