氟哌酸分子印迹共混膜的制备及结构表征

以氟哌酸为模板分子,α-甲基丙烯酸为功能单体,三甲氧基丙烷三甲基丙烯酸酯为交联剂,利用本体聚合方法制备了具有特异选择性的氟哌酸分子印迹聚合物,并利用聚砜与氟哌酸分子印迹聚合物共混的方法制备了分子印迹聚合物膜.运用红外光谱分析和透射电子显微镜研究了氟哌酸分子印迹聚合物的结构.运用扫描电子显微镜研究了分子识别膜的机理和吸附性能,运用平衡结合实验法证明了分子识别膜对氟哌酸表现出了较高的选择性.     

Silica nanoparticle supported molecularly imprinted polymer layers with varied degrees of crosslinking for lysozyme recognition

Surface imprinting over nanosized support materials is particularly suitable for protein templates, considering the problems with mass transfer limitation and low binding capacity. Previously we have demonstrated a strategy for surface protein imprinting over vinyl-modified silica nanopartiles with lysozyme as a model template by polymerization in high-dilution monomer solution to prevent macrogelation. Herein, the synthesis process was further studied toward enhancement of the imprinting performance by examining the effect of several synthesis conditions. Interestingly, the feed crosslinking degree was found to have a great impact on the thickness of the formed imprinting polymer layers and the recognition properties of the resulting imprinted materials. The imprinted particles with a crosslinking degree up to 50% showed the best imprinting effect. The imprinting factor achieved 2.89 and the specific binding reached 23.3 mg g⁻¹, which are greatly increased compared to those of the lowly crosslinked imprinted materials reported previously. Moreover, the relatively high crosslinking degree led to no significant retarding of the binding kinetics to the imprinted particles, and the saturated adsorption was reached within 10 min. Therefore, this may be a promising method for protein imprinting.     

Preparation of Z-L-Phe-OH-NBD imprinted microchannel and its molecular recognition study

An integrated microchip was presented for selective recognition of Z-L-Phe-OH-NBD, using molecular imprinting technique. Molecularly imprinted polymer (MIP) were prepared by copolymerization in the presence of template molecule Z-L-Phe-OH-NBD, in which methacrylic acid and 4-vinylpyridine were used as functional monomers and ethylene dimethacrylate used as crosslinker. Imprinted polymer particles were introduced into a microchannel fabricated with a new material i.e. poly(methylvinylsiloxane) by simply rapid prototyping method. Imprinted effects were evaluated by laser-induced fluorescence (LIF) detection where the results indicated that good selective recognition for Z-L-Phe-OH-NBD in the imprinted polymer was obtained; the adsorption percentage of Z-L-Phe-OH-NBD was 61%. In contrast to conventional molecular imprinting analysis, integration shortened overall analysis time from 4h to 10 min.     

应用分子印迹-固相萃取法提取中药活性成分非瑟酮

分别以中药黄栌的主要成分非瑟酮为印迹分子、 丙烯酰胺为功能单体及乙二醇二甲基丙烯酸酯为交联剂, 通过封管聚合法合成了分子印迹聚合物; 将其装于自制的固相萃取柱中, 研究了以不同体积比的乙醇-水溶液为溶剂时非瑟酮在柱上的保留行为; 通过优化清洗及洗脱条件, 使非瑟酮与它的结构相似物槲皮素在柱上得到了很好的分离.     

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％．     

Synthesis and characterization of micro/nanoparticles of poly(vinylalcohol-co-vinylcinnamate) derivatives

Various poly(vinylalcohol-co-vinylcinnamate) derivatives including poly(vinylalcohol-co-vinylcinnamate), poly(vinylalcohol-co-vinyl-4-methoxycinnamate), poly(vinylalcohol-co-vinyl-2,4-dimethoxycinnamate) and poly(vinylalcohol-co-vinyl-2,4,5-trimethoxycinnamate) were synthesized by grafting poly(vinylalcohol) with appropriate cinnamoyl groups. The self-assembly of grafted products into spherical micellar nanoparticles was performed, and particles were analyzed using dynamic light scattering, scanning electron microscopy, and transmission electron microscopy. ¹H NMR analyses of the well-dispersed micellar particle suspensions and polymer solutions indicated that the hydroxyl groups of the polymer were on the outer surface of the spheres, while the cinnamoyl moieties were buried inside the spheres forming crystalline structure. Polymer with a higher degree of cinnamoyl substitution gave smaller particles upon self-assembly. Variations in particle sizes obtained from PV(OH) grafted with cinnamoyl derivatives of different methoxy substitution on the benzene ring were observed. Molecular weight of the polymers did not significantly affect nanoparticle size and morphology. In addition, self-assembly of the poly(vinylalcohol-co-vinylcinnamate) derivatives into hollow reverse micellar microparticles of uniform size was also demonstrated. ¹H NMR spectrum of the reverse micellar micro-particle suspension indicated that the cinnamoyl moieties were not in a crystalline state.     

Synthesis of molecularly imprinted polymer of βcyclodextrin for the efficient recognition of cholesterol

Polymeric receptors for cholesterol were synthesized by crosslinking β-cyclodextrin (β-CyD) with hexamethylene diisocyanate or toluene 2,4-diisocyanate in dimethyl sulfoxide (DMSO) in the presence of cholesterol as the template. Non-imprinted β-CyD polymers were much poorer in the cholesterol adsorption. When β-CyD was cross-linked by epichlorohydrin in aqueous alkaline solutions (even in the presence of cholesterol), the cholesterol adsorbing activity was nil. Use of DMSO as the cross-linking solvent is necessary for the imprinting, since β-CyD molecules form inclusion complexes with cholesterol in this solvent and thus their mutual conformation in the polymer is regulated appropriately for cholesterol binding. The adsorbed cholesterol was completely removed from the polymers by treating the adducts with ethanol, indicating a strong potential for practical applications.     

Chromatographic characterization of a molecular imprinted polymer binding cortisol

A cortisol-binding polymer was prepared by utilising a non-covalent molecular imprinting polymerisation technique. The obtained polymer was packed in a high-performance liquid chromatography (HPLC) column; the selectivity was studied by liquid chromatography, eluting cortisol, cortisone, corticosterone, progesterone, 11-ketoprogesterone, 11alpha-hydroxyprogesterone, 17alpha-hydroxyprogesterone, cortisol 21-hemisuccinate, and cortisol 21-acetate with chloroform, containing 0.5% (v/v) acetic acid, as mobile phase. The mechanism of molecular imprinting was confirmed and a good selectivity for cortisol, with limited recognition for cortisone and 11alpha-hydroxyprogesterone, was found.     

EDTA-β-CD交联聚合物的微波合成及其吸附性能

以β-环糊精(1)为原料,乙二胺四乙酸(2)为交联剂,聚乙二醇(PEG-400)为改性剂,磷酸二氢钠(MSP)为催化剂,采用微波法合成了一种双功能吸附剂——EDTA-β-CD交联聚合物(3),其结构经IR确证。通过单因素实验和响应曲面分析法优化了3的合成条件。结果表明:在最优反应条件(1 4.00 g,2 6.00 g,MSP 2.73 g,PEG-400 0.5 g,于90℃,80 W反应60 min)下,3产率70%。采用废水中亚甲基蓝(MB)和Cu2+的吸附实验研究了3的吸附性能。结果表明:3可同时吸附废水中的MB和Cu2+,吸附率分别为86.3%和96.2%。     

Preparation of sterol-imprinted polymers with the use of 2-(methacryloyloxy)ethyl phosphate.

Steroid-selective polymers were prepared by the molecular imprinting technique, using 2-(methacryloyloxy)ethyl phosphate as functional monomer. The retentivity and selectivity of the obtained imprinted polymers were evaluated by liquid chromatography. The cholesterol-imprinted polymer showed higher affinity for cholesterol than that for cholesterol derivatives. The selectivity of the imprinted polymer was superior to the imprinted polymer prepared with the conventional functional monomer, 2-(trifluoromethyl)acrylic acid. Estradiol was also imprinted and gave similar results, demonstrating that 2-(methacryloyloxy)ethyl phosphate would be suitable for imprinted polymers of cholesterol and related compounds.     

胆固醇分子印迹的聚合有机凝胶及其吸附性能研究

报道了一种新型胆固醇分子印迹的聚合有机凝胶.以3-胆固醇酰氧基丙酸(COPA)为模板分子,通过可聚合凝胶剂N-十八烷基马来酰胺酸(ODMA)在甲基丙烯酸β-羟乙酯、甲基丙烯酸和聚乙二醇二甲基丙烯酸酯混合溶液的自组装,首先形成稳定的超分子有机凝胶,经UV光引发原位聚合,再经乙醇提取模板分子后制得胆固醇非共价印迹的聚合有机凝胶.偏光显微镜(POM)和场发射扫描电镜(FE-SEM)表明ODMA在单体混合物中自组装形成带状聚集体,这为其后形成的印迹聚合有机凝胶的孔穴稳定性提供了保证.印迹聚合有机凝胶对胆固醇的吸附效率可达到64%,并与ODMA和COPA的含量有关.实验表明,当ODMA的含量由1wt%增加到3 wt%时,吸附量由15.7 mg/g增加到22.9 mg/g.当COPA的含量由4 wt%增加到7 wt%时,吸附量由16.8 mg/g增加到22.2 mg/g.然而,当ODMA含量过多时,吸附量反而下降,这主要归因于体系网络密度的增加导致扩散阻力增加.而COPA含量过多时,可能干扰ODMA的自组装,影响印迹孔穴的稳定性,同样使得吸附量下降.     

Molecular imprinting of β-cyclodextrin/cholesterol template into a silica polymer for cholesterol separation

The molecular assembly formed by the inclusion complex of cholesterol in β-cyclodextrin (β-CD:chol) was used as a template for the molecular imprinting of a sol–gel polymer (MIP/β-CD:chol), produced with tetraethoxysilane (TEOS) as precursor. The MIP/β-CD:chol and pure silica matrix (PSM) were tested for the efficiency of cholesterol removal from solutions at different cholesterol concentrations (1–10 mg/mL). The adsorption tests were run at 25°C using 1% (w/v) solid/liquid suspensions during 24 h. The MIP/β-CD:chol data on cholesterol adsorption was fitted by the Langmüir isotherm model, giving a maximum adsorption capacity of 76.5 mg cholesterol/g-adsorbent. The PSM data did conform to the Langmüir model. The maximum cholesterol adsorption achieved with the PSM was higher, 251 mg/g, probably due to multilayer adsorption. The hydrophobic silica matrix, imprinted with the inclusion complex of β-CD and a target molecule, has the potential of being used as an adsorbent for other organic molecules.     

Chromatographic characteristics of cholesterol-imprinted polymers prepared by covalent and non-covalent imprinting methods

Cholesterol-imprinted polymers were prepared in bulk polymerization by the methods of covalent and non-covalent imprinting. The former involved the use of a template-containing monomer, cholesteryl (4-vinyl)phenyl carbonate, while the latter used the complexes of template and functional monomer, methacrylic acid or 4-vinylpyridine prior to polymerization. Columns packed with these molecularly imprinted polymers (MIPs) were all able to separate cholesterol from other steroids. For different combinations of cholesterol and beta-estradiol concentrations in a total of 1 g/l, the peak retention times for both compounds were nearly constant. The adsorption capacity for cholesterol onto the MIPs was found to significantly depend on the use of functional monomers, but the selectivity factors were only slightly different from each other at 2.9 to 3.2 since the separation was all based on the specific binding of cholesterol to recognition sites formed on the imprinted polymers. The capacity factors for cholesterol were determined to be 3.5, 4.0 and 3.1, respectively, for covalently imprinted, 4-vinylpyridine-based, and methacrylic acid-based non-covalently imprinted polymers. However, the covalently imprinted polymer was found to have a higher adsorption capacity for cholesterol and about fivefold higher chromatographic efficiency for cholesterol separation, in comparison with non-covalently imprinted polymers. The use of covalent imprinting significantly reduced the peak broadening and tailing. This advantage along with constant retention suggests that the covalently imprinted polymer has potential for quantitative analysis.     

The preparation of bovine serum albumin surface-imprinted superparamagnetic polymer with the assistance of basic functional monomer and its application for protein separation

Currently, small proteins imprinting are more reported since large proteins molecular imprinting faces challenge due to their bulk size and complex structure. In this work, bovine serum albumin (BSA) surface-imprinted magnetic polymer was successfully synthesized based on atomic transfer radical polymerization (ATRP) method in the presence of common monomer (N-isopropylacrylamide) with the assistant of basic functional monomer (N-[3-(dimethylamino)propyl]-methacrylamide), which provides a achievable attempt for imprinting larger target proteins based on the ATPR with the mild reaction conditions. The BSA-imprinted polymer exhibited higher adsorption capacity and selectivity to BSA over the non-imprinted polymer. Competitive adsorption tests indicated the BSA-imprinted polymer had better selective adsorption and recognition properties to BSA in the mixture. The obtained BSA-imprinted polymer was applied to bovine serum, which also showed selectivity to BSA. In addition, a conventional aqueous two-phase solution of PEG/sulphate was used as elution for adsorbed BSA, which was compared with common NaCl elution.     

A sol-gel derived pH-responsive bovine serum albumin molecularly imprinted poly(ionic liquids) on the surface of multiwall carbon nanotubes

A pH-responsive surface molecularly imprinted poly(ionic liquids) (MIPILs) was prepared on the surface of multiwall carbon nanotubes (MWCNTs) by a sol-gel technique. The material was synthesized using a 3-aminopropyl triethoxysilane modified multiwall carbon nanotube (MWCNT-APTES) as the substrate, bovine serum albumin (BSA) as the template molecule, an alkoxy-functionalized IL 1-(3-trimethoxysilyl propyl)-3-methyl imidazolium chloride ([TMSPMIM]Cl) as both the functional monomer and the sol-gel catalyst, and tetraethoxysilane (TEOS) as the crosslinking agent. The molecular interaction between BSA and [TMSPMIM]Cl was quantitatively evaluated by UV–vis spectroscopy prior to polymerization so as to identify an optimal template/monomer ratio and the most suitable pH value for the preparation of the MWCNTs@BSA-MIPILs. This strategy was found to be effective to overcome the problems of trial-and-error protocol in molecular imprinting. The optimum synthesis conditions were as follows: template/monomer ratio 7:20, crosslinking agent content 2.0–2.5 mL, temperature 4 °C and pH 8.9 Tris–HCl buffer. The influence of incubation pH on adsorption was also studied. The result showed that the imprinting effect and selectivity improved significantly with increasing incubation pH from 7.7 to 9.9. This is mainly because the non-specific binding from electrostatic and hydrogen bonding interactions decreased greatly with the increase of pH value, which made the specific binding affinity from shape selectivity strengthened instead. The polymers synthesized under the optimal conditions were then characterized by BET surface area measurement, FTIR, thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The adsorption capacity, imprinting effect, selective recognition and reusability were also evaluated. The as-prepared MWCNTs@BSA-MIPILs were also found to have a number of advantages including high surface area (134.2 m² g⁻¹), high adsorption capacity (55.52 mg g⁻¹), excellent imprinting effect (imprinting factor of up to 5.84), strong selectivity (selectivity factor of 2.61 and 5.63 for human serum albumin and bovine hemoglobin, respectively), and good reusability.     

Hemoglobin-imprinted polymer gel prepared using modified glucosamine as functional monomer

A new functional glycomonomer was obtained from modified glucosamine. Hemoglobin-imprinted polymer gel was prepared with allyl-bromide modified glucosamine as functional monomer, poly（ethylene-glycol）diacrylate （PEGDA） as cross-linker and ammonium persulfate [（NHn）2S2O8]/sodium hydrogen sulfite （NaHSO3） as initiators in a phosphate buffer. The adsorption capacity and selective adsorption of the molecular imprinting polymer （MIP） were also discussed.     

Molecular imprinting of cyclodextrin to physiologically active oligopeptides in water

β-Cyclodextrin (β-CyD)-based polymeric receptors for γ-endorphin (γ-endor, an opioid heptadecapeptide) were prepared using the molecular imprinting method. When mono-3-(N-acrylamido)-3-deoxy-β-CyD bearing a vinyl group in the secondary hydroxyl side of the cavity of β-CyD was polymerised in water in the presence of γ-endor, the binding activity of the β-CyD polymer to this peptide in water was enormously promoted by the imprinting. By contrast, the bindings towards methionine–enkephalin (N-terminal pentapeptide of γ-endor) and its homologue leucine–enkephalin were suppressed. Thus, the binding of γ-endor by the imprinted polymer was highly selective. The imprinting towards γ-endor was also successful with the use of the β-CyD monomer bearing a vinyl group in the primary hydroxyl side of the cavity, although the recognition was less strict. Various factors affecting the imprinting efficiency (kinds of β-CyD vinyl monomer and template, as well as the pH of imprinting mixture) are discussed.     

Kinetic study for adsorption of α-naphtholphthalein onto silica gel surface-imprinted polymer and non-imprinted polymer

In this study, the molecular imprinting polymer (MIP) was prepared using α-naphtholphthalein as a template, 2-(diethylamino)ethyl acrylate as a functional monomer and ethylene glycol dimethacrylate as a crosslinking agent by aid of free radical polymerization onto surfaces of vinyltrimethoxysilane modified silica gel. The MIP was extracted with acetonitrile for overnight to remove the template molecule from the MIP. Non-imprinted polymer (NIMP) was synthesized using the same materials except α-naphtholphthalein as template molecule. α-Naphtholphthalein adsorption on surfaces of the both polymer was studied at three different temperatures (19°C, 25°C and 35°C). It was observed that the adsorption capacity increased with increasing temperature and with time. The time required to reach the equilibrium for two polymers and all temperature was accepted to be nearly 6 h. The saturated adsorption amounts at the equilibrium were found as 120 mg/g, 123 mg/g and 127 mg/g at 19°C, 25°C and 35°C, respectively, for MIP, and 78 mg/g, 98 mg/g and 120 mg/g at 19°C, 25°C and 35°C, respectively, for NIMP. The mechanism of adsorption of α-naphtholphthalein onto MIP and NIMP is nearly appropriate to pseudo-first-order kinetic model with an activation energy of 11.63 kJ/mol for MIP, and 23.69 kJ/mol for NIMP. Thermodynamic parameters of activated complex in the adsorption process showed that the adsorption was carried out with an endothermic activation enthalpy, large negative entropy changes and the positive values of ΔG* that the adsorption processes is not favorable.     

溶菌酶分子印迹聚合物膜的制备及其吸附性能

以溶菌酶为模板蛋白质，结合分子印迹技术在硅烷化的基质玻片上制备了溶菌酶分子印迹聚合物膜。实验优化了溶菌酶聚合物膜的印迹体系，考察了溶菌酶分子印迹聚合物膜的吸附平衡时间、最大吸附量、特异识别能力、重复使用性以及对实际样品中溶菌酶的分离情况。结果表明，在最优条件下，制备的分子印迹聚合物膜对溶菌酶具有特异吸附能力，印迹因子为3.0，吸附平衡时间为5 min，吸附行为符合Langmuir吸附模型，理论最大吸附量为42.5 mg/g，实际样品中的吸附量为30 mg/g。且此印迹聚合物膜在重复使用5次后，最大吸附量仅下降了5%，具有良好的重复使用性。该方法为复杂生物样品中目标蛋白质的分离富集提供了一种快速、高效的手段。     

橙皮苷印迹聚合物的识别性能及机理研究

为了制备对橙皮苷(HES)具有特定识别能力的吸附材料,以HES为模板分子,丙烯酰胺(AM)为功能单体,甲基丙烯酸乙二醇酯(EDMA)为交联剂,在甲醇中制备了HES印迹聚合物(MIP),采用平衡吸附实验方法研究了聚合物的吸附性能和选择性能,探讨了聚合物的印迹机理和识别机理.结果表明,MIP对HES具有较高的亲和性和选择性.当HES浓度为0.048 mmol/L时,MIP及相应NMIP对HES的分配系数KD分别为10.17 和2.973,印迹因子α达到3.421.MIP对结构相似物芦丁及柚皮苷的选择因子β分别为2.446和1.246.机理研究表明识别位点来自AM与HES苯甲酰系统的氢键作用,吸附溶液中水含量的增加对MIP的识别能力有较大的影响.最后,以高效液相色谱研究了MIP在样品中的分离富集能力,表明该印迹聚合物具有一定的应用潜能.