Design And Synthesis Of Biomolecules Imprinted Polymer By Dummy Template Imprinting And Imprinting Mechanism Research

In recent years,the molecularly imprinting technology has become one of a hot research in analytical chemistry,and it is mainly focused on the small organic molecules.However,the imprinting of biologic molecules,especially the amino acid,peptide and protein.Still faces severe challenges,such as incompatible with the week polarity organic solvent,flexible conformation,complex structures,and more binding sites.Firstly,the biological molecules must be the noncovalent imprinting is sensitive to even slight disruption of the interactions holding the complex together?for example,the presence of water?,and it is therefore not very robust.Secondly,there were very few functional monomers and cross-linker that suit for biological molecules imprinting in aqueous.In addition,many inherent problems of biological macromolecules hinder the advancement of their imprinting,such as large molecular size,structural complexity,environmental sensitivity,and flexible conformation.Therefore,it is imperative to develop novel strategies for the imprinting of biological molecules.The object of this work is to achieve the effective imprinting and accurate recognition of biological molecules.In order to solve the long plagued problem of low efficiency of molecularly imprinted polymers?MIPs?.This work is focused on forming the structural stability of biological template-monomer complex in pre-polymerization solution and recognition process of obtaining molecularly imprinted polymers for a target molecule over molecular dynamics?MD?simulation.The main research contents and results are listed as follows:?1?The MIPs is determined by the proper selection of a functional monomer capable of forming a stable monomer-template complex.In order to rational design the biological MIPs with high specific recognition toward target molecules,the MD technique was carried out to research the biological template-monomer complex in aqueous.In this work,the L-phenylalanine?L-Phe?act as template.Materials Studio 6.1 was used to screen functional monomers by calculating the binding energy of the complex between L-Phe with 18monomers.The results show that the acrylic acid?AA?and acrylamide?AM?are good functional monomers for L-Phe imprinting,and the hydroxyl ethyl methacrylate?HEMA?and4-vinyl pyridine?4VP?are not conducive to obtain high selective MIPs.To verify the reliability of the results of MD,four kinds of MIPs were synthesized.Their selective factor was 2.63?MIPs1,the AA as a functional monomer?,2.55?MIPs2,the AM as a functional monomer?,2.18?MIPs3,the HEMA as a functional monomer?and 2.14?MIPs4,the 4VP as a functional monomer?,respectively.The results of experiments and MD are consistent.To further investigation of the imprinting mechanism of L-Phe MIPs,the crosslinked network of MIPs were established by MD method,and the interaction between each MIPs and L-Phe was researched.The results indicated that the accurate imprinting cavity was formed in MIPs1,which have five hydrogen bonds between MIPs1 and L-Phe.For MIPs2,there were two hydrogen bonds.But there is one?or zero?hydrogen bonds were observed between MIPs3?or MIPs4?and L-Phe in imprinting cavity.All these results show that the MD method could be a candidate for reasonable design biological molecules imprinted polymers in water,and it is also as a tool for imprinting and recognition mechanism of MIPs research.?2?The porogenic solvent plays a critical role for selectivity of molecularly imprinted polymers due to their solvation effect,which governs the stability of the pre-polymerization complex during the imprinting process.In this present work,the 1-butyl-3-methylimidazolium aminohydrocinnamic acid dummy template imprinted polymers was prepared in water,ethanol,DMSO,acetonitrile and chloroform,respectively.And the influence of the porogen on the selectivity of dummy template imprinted polymers was investigated for L-phenylalanine recognition.The results indicated that the affinity of obtained dummy template for L-phenylalanine increased with the above mentioned solvent sequence.It coincides with the Kamlet-Taft solvatochromic parameters,which represents the capacity to form hydrogen bonds between solvent and solute.Subsequently,the fluorescence quenching analysis and molecular dynamics simulations were carried out.All these results shown that the dummy template imprinted method is a useful way to improve the specific recognition of molecularly imprinted polymers,and the Kamlet-Taft solvatochromic parameters would be the basis for selection of porogen during molecularly imprinted polymers preparation.The results indicate that the chloroform was the best prorgen for dummy template imprinting,and the selective factor of MIPs for L-Phe up to 4.44.?3?Ionic liquid based molecularly imprinted polymers have attracted considerable attention as a biomimetic recognition materials due to water-compatibility and high binding capacity.However,the selective recognition was unsatisfactory.In order to overcome this defect,we developed a novel dummy template ionic liquid based molecularly imprinted polymer,which use 1-butyl-3-vinylimidazolium?-aminohydrocinnamic acid salt as a functional monomer and dummy template.The binding experiment shows that the obtained molecularly imprinted polymer possesses high binding capacity(161.49?mol·g^-1),imprinting factor?3.17?,the selective factor?5.83?.In addition,the obtained MIPs can be enantioseparation D,L-Phe racemate.The e.e.%value of L-Phe was up to 97.64%when racemate was separated by ion-pair dummy template MIPs.The molecular simulation results demonstrated that the high selectivity is attributed to forming the ion-pairs between imidazolium and L-phenylalanine,which might be located in imprinted cavities to improve imprinted efficiency.?4?In order to achieve the effective imprinting and accurate recognition of biological macromolecules.Herein,the C-terminal nonapeptide of Cytochrome C?Cyt C?was act as a template,the combined methods of the ion-pair dummy template imprinting method and Pickering emulsion polymerization was used to prepare interface MIPs.Results show that the obtained PEP@IL@MIPs displayed a fast recognition rate?22 min the adsorption reached equilibrium?toward Cyt C.Subsequently,Canonical Monte Carlo?CMC?simulations were performed using the Sorption package in Materials Studio 6.1 to identify and characterize the specific binding sites of obtained PEP@IL@MIPs.The results indicate that the precise imprinting cavities were formed in PEP@IL@MIPs due to the induction effect of imidazolium to C-terminal nonapeptide of Cyt C.The obatined MIPs was employed as sorbent to separate the Cyt C from the quaternary protein mixtures?Cyt C/lysozyme/bovine serum albumin/bovine hemoglobin?.The results indicated that the obtained MIPs has a good selection for Cyt C?the selective factor was 7.09?.Thus,the ion-pair dummy imprinting combined with Pickering emulsion polymerization is a useful way to improve the specific recognition of peptides MIPs,so that this method offers promising new applications in the field of proteomics.It could also be suggested as an important research idea for the future biological molecules imprinting technology.