Preparation Of Magnetic Deep Eutectic Solvents Molecularly Imprinted Polymers And Study On The Recognition Property For The Proteins

Molecular imprinted technology(MIT)is a preparative technique which could obtain the polymer that possesses peculiar recognizability for template molecule.In recent years,as a new type and high selectivity adsorption separation technology,MIT has rapidly developed,applied in many fields.The specific binding between molecular imprinted polymers and template protein is similar to the natural binding of"antigen-antibody",and the molecular imprinted polymers have advantages such as stability,efficient and high repeatability which natural antibodies do not have.However,compared with the rapid development on the aspect of small molecule,the direction of protein molecular imprinting has become a significant and challenging research field due to the complex conformation,flexible structure and large size of protein.The deep eutectic solvents(DES)is a novel green solvent,usually composed of Hydrogen-Bond Acceptor with a certain molar ratio of Hydrogen-Bond Donor,which freezing point is significantly lower than the melting point of pure material of each component.Deep eutectic solvents(DES)shares the same properties with ionic liquid,including low vapor pressure,solubility,electrochemical stability.Moreover,it has the unique feature of simple preparation,non-toxic and biodegradability.As a new-type green solvent,it has been applied in multiple aspects,but the study in the field of molecular imprinting still not mature.Therefore,it is very significant to study the application of DES in molecular imprinting direction.In this study,three types of magnetic molecularly imprinted polymers for the selective recognition and separation of proteins were prepared by the combination of deep eutectic solvents and molecular imprinted technology.(1)Preparation of magnetic molecularly imprinted polymer based on MAA-ChCl deep eutectic solvents as monomer for the recognition and separation of proteinsA novel and facile magnetic deep eutectic solvents(DES)molecularly imprinted polymers(MIPs)for the selective recognition and separation of Bovine hemoglobin(BHb)was prepared.The magnetic DES-MIPs were synthesized by using MAA-ChCl DES as the functional monomer,Fe3O4 as a magnetic provider and Bovine hemoglobin(BHb)as the template protein.The obtained particles were characterized by FT-IR,TGA,FESEM,TEM,DLS,VSM and elemental analysis.The results suggested that the imprinted polymers were successfully formed and possessed a charming magnetism.The imprinted particles reached the equilibrium adsorption within 4 h while it took 6 h for the non-imprinted particles controlled to achieve the saturation sorption.In addition,it is noted that the adsorption capacity of magnetic DES-MIPs was significantly higher than that of magnetic DES-NIPs,and the maximum adsorption capability and the imprinting factor of magnetic DES-NIPs were estimated to be 175.44 mg/g and 4.57.Last but not least,the magnetic DES-MIPs presented outstanding recognition specificity and selectivity so that it can be utilized to separate template protein from the mixture of proteins and real samples.(2)Preparation of molecularly imprinted polymer based on deep eutectic solvents double bond-modified magnetic nanoparticles carrier for the recognition and separation of lysozyme.With the lysozyme as template protein,IA-ChCl deep eutectic solvents modified Fe3O4 as carrier and acrylic acid as functional monomer,a new kind of magnetic molecularly imprinted polymers for the recognition and separation of lysozyme were prepared(MIP-Fe3O4@DES@AA).Fourier transform infrared spectrometry,thermogravimetric analysis,field emission scanning electron microscope and vibrating sample magnetometer(VSM)were used to characterize the composition of the obtained particles.The study discussed the synthesis formulation of MIP-Fe3O4@DES@AA,and the optimized monomer acrylic acid content of 120 ?L and template protein lysozyme content of 25 mg were chosen.The MIP-Fe3O4@DES@AA could absorb protein rapidly within a period of 2 h and reach the equilibrium adsorption within 8 h in 1.0 mg/mL lysozyme solution,the imprinting factor was 4.48.Meanwhile,the adsorption isotherm was consistent with Langmuir model and the theoretical maximum adsorption capacity was 106.38 mg/g.The selective adsorption experiments and competitive batch rebinding tests both showed outstanding specificity and selectivity in the recognization of lysozyme.Lastly,the reusability experiment was studied and the result demonstrated that MIP-Fe3O4@DES@AA still maintain a high stability and good reusability after five times repeat.(3)Preparation of magnetic molecularly imprinted polymer based on IA-ChCl deep eutectic solvents as monomer for the recognition and separation of bovine hemoglobinA kind of magnetic molecularly imprinted polymers(MIP-Fe3O4@DES)were synthesized by using IA-ChCl deep eutectic solvents as the functional monomer,Fe3O4 as a magnetic provider and Bovine hemoglobin(BHb)as the template protein.The preparation method simplified the modification of Fe3O4,and directly used the eutectic solvent to synthesize the imprinted polymer on the surface of the particles.The analysis of infrared,thermogravimetric,transmission electron microscopy and magnetic hysteresis loops showed that the "shell core" polymer was finally synthesized.The results of thermodynamic adsorption and kinetic adsorption demonstrated that MIP-Fe3O4@DES could reach the equilibrium adsorption at the optimum bovine hemoglobin concentration of 1.2 mg/mL within 5 h and the imprinting factor was estimated to be 2.89.Besides,the adsorption isotherm was consistent with Langmuir model and the theoretical maximum adsorption capacity was 196.08 mg/g.Selective adsorption experiments and competitive adsorption experiments indicated that MIP-Fe3O4@DES could separate bovine hemoglobin form a single environment and binary protein mixture environment and have a very good ability to specifically recognize template proteins.The real sample adsorption experiment makes it possible to apply the MIP-Fe3O4@DES to the complex sample separation analysis so that the MIP possess a certain practicability.Lastly,the reusability experiment was studied and the MIP-Fe3O4@DES could be reused more than four times.This result showed the MIP-Fe3O4@DES possess a high stability and good reusability.