Preparation of Molecular Imprinted Copolymer Membrane for Uracil Recognition

Uracil molecular imprinted membrane was prepared by phase inversion technique with [P(AN-co-MAA)] copolymer. SEM photograph shows that the resultant membrane has a typical ultrafiltration structure with Water Volume Flux of 3.7?0-5m3/m2穝, and uracil substrate permeation experiment shows that the resultant membrane can bind uracil into its structure, and shows a binding equilibrium.

Enantiomeric Resolution on L-Carnitine Selective Polymers Prepared by Molecular Imprinting

L-carnitine selective polymers were prepared by molecular imprinting using methacrylic acid as the functional monomer. The acid function of the monomer is expected to form hydrogen bond and ionic interactions with the amine function of the target molecule L-carnitine. The imprinted polymers were used as stationary phases in high-performance liquid chromatography (HPLC). It was shown that L-carnitine imprinted polymer exhibited a higher affinity to its template molecule, while the non-imprinted polymer had no affinity to the compounds tested. Racemic carnitine hydrochloride was efficiently resolved on the L-carnitine imprinted polymer, and the separation factor is 1.9.

Molecular Imprinting Fibrous Membranes of Poly(acrylonitrile-co-acrylic acid) Prepared by Electrospinning

IntroductionOver the past few decades, molecular imprinting has been described as a technology for preparing ＂molecular doors＂ which can be matched to ＂template keys＂. It has been found to be a simple and effective approach to introduce specific recognition sites into synthetic polymers, namely, to create molecular imprinting polymers Remarkable features such as stability, ease of preparation and low cost, have made molecular imprinting polymers particularly attractive in chemical sensors, catalysis, drug delivery, and dedicated separations. Practical applications of molecular imprinting polymers require accessible sites, fast mass transfer, and quick binding. However, present techniques used to prepare molecular imprinting polymers most often result in materials exhibiting a high affinity and selectivity but a low capacity and poor site accessibility for the target molecules. It is also very difficult to remove the imprinted molecules located in these molecular imprinting polymers because the highly cross-linked structures do not allow the templates to move freely. To some extent, combining molecular imprinting technology with membrane separation and surface imprinting can overcome the shortcomings, such as mass transfer limitations and non-quantitative recovery of the template molecules seen for imprinted materials fabricated by conventional bulk methods. In that ease, it appears to us that molecular imprinting polymers with high surface area to volume ratios are particularly desirable for largescale applications. Eleetrospun nano and ultrafine fibrous membranes are the most suitable materials due to advantages such as： （1） large specific surfaces, providing relatively high imprinting sites per unit mass; （2） fine porous structures, resulting in the accessibility of imprinting sites and low diffusion resistance necessary for high efficiency; and （3） easy recoverability from practical operation or applicability for continuous usages. Therefore, in this work, we prepared a unique kind of imprinted material--molecularly imprinted fibrous membranes of poly （ acrylonitrile-co-acrylic acid） fabricated by means of an electrospinning process.

Molecular Imprinting of (R)-(+)-α-Methylbenzylamine for Chiral Stationary Phase

A new type of molecular imprinting stationary phase was prepared by using R- (+)-α -methylbenzy lamine as the print molecule. Experiments of high performance liquid chromatography show that the new stationary phase has high enantio-selectivity and discriminates (R, S) -(± )- α -methylbenzylamine successful ly with α value of 1. 67

Computer Simulation and Experimental Investigations of Phenobarbital Molecular Imprinting System

The interaction process between the phenobarbital（PHN） and acrylamide（AM） was studied using the M062X/6-31G（d,p） method. The PHN and AM were used as the template and functional monomer,respectively. The molecular electrostatic potential（MEP） was simulated for predicting the reactive sites. The atoms in molecules theory helped to reveal the imprinting mechanism and optimize the molar ratios for PHN and AM. The molecular imprinted polymers（MIPs） containing PHN were synthesized through the precipitation polymerization. The diameter range of the obtained MIPs was from 150 to 390 nm. According to the computational results,MIPs with the molar ratio of PHN and AM equal to 1：6 showed high selective adsorption for PHN. The apparent maximum adsorption quantity（Q_（max）） of MIPs toward PHN was 7.9 mg/g,and the Qmax of nonimprinted polymer microspheres（NIPs） was 3.2 mg/g. Herein,the studies can provide theoretical and experimental references for the controllable fabrication of MIPs.

Development of a competitive format sorbent assay for the determination of parathion in water using molecular imprinted polymer as specific sorbent carrier

A rapid,simple,and reliable competitive molecular imprinted polymer sorbent assay（MIPSA） was developed and validated for measurement of parathion in water samples.This assay employed a molecular imprinted polymer（MIP） that was synthesized with non-covalent imprinting method as capture reagent and p-aminoparathion conjugate of horseradish peroxidase（para-HRP） as an enzyme label.The assay depended on a competitive binding reaction between the enzyme conjugate and analyte for the binding sites of the MIP.The optimized analysis conditions of 10 ng mL-1 para-HRP and 10 mg mL-1 polymer were found.The assay was acceptable to detect parathion in water samples under the optimized conditions,with a limit of detection of 50 ng mL-1.Mean analytical recoveries of added parathion in water samples ranged from 101.2%to 105%.The precision of the assay was satisfactory; relative standard deviation ranged from 4.3%to 6%.

Simulation and Preparation of Molecular Imprinting System with Atrazine as Template

In this work, atrazine functions as a template molecule, and trifluoromethacrylic acid （TFMAA）, methacrylic acid （MAA）, methyl methacrylate （MMA）, and acrylamide （AM） serve as functional monomers, respectively. By using density functional theory （DFT）, the computational approach was carried out to simulate the self-assembly system of template and functional monomer. The geometry optimization, action sites, binding energies, and molecular imprinting mechanism of complexes with different functional monomers in different proportions were predicted. The simulation results showed that atrazine and the functional monomers interacted through hydrogen bond. Among the 4 functional monomers, the imprinted complex formed by TFMAA and atrazine with a ratio of （1：6） has the lowest binding energy and the best imprinting effect. Then, the microspheres of molecularly imprinted polymer （MIPs） were prepared by precipitating polymerization using atrazine as the template molecule and TFMAA as the functional monomer. The microspheres were observed by scanning electron microscopy （SEM）. The results showed that atrazine MIP microspheres had average particle size of 400 nm, which was greater than the non-imprinted polymeric microspheres （NIPs）. Dynamic adsorption experiments of MIPs showed that the adsorption reaction reached balance after 200 min. Analysis of the Scatchard plot revealed that the binding sites of MIPs to atrazine were equal class under the studied concentration range. The dissociation constant （Kd） and apparent maximum adsorption quantity （Qmax） of MIPs were 3.6×10^-5 mol/L and 4.83μmol/g, respectively. The study of selective adsorption between atrazine and metribuzin showed that imprinted microspheres had high selectivity for the template molecule atrazine.

Simultaneous Chiral Separation Using a Combinatorial Molecular Imprinting Phase

Molecular imprinting chiral stationary phase against Cbz-L-Serine (Cbz-L-Ser) and Cbz-L-Alaine (Cbz-L-Ala) were prepared utilizing acrylamide + 2-vinylpyridine as combined basic functional monomers. Cross-selectivity was used to obtain simultaneous chiral separations of Cbz-DL-Ser and Cbz-DL-Ala by connecting two columns packed with Cbz-L-Ser and Cbz-L-Ala imprinted chiral stationary phase, respectively.

Molecular Imprinted Membrane with High Flux by Surface Photo-grafting Copolymerization

Molecular imprinted polymer membranes (MIM) combine the merits of molecular imprint and membrane technology. In this work, a very thin of imprinted polymer that can specifically and selectively absorb the basic template (adenine) was grafted on the surface of polyvinylidene fluoride membrane by photo-grafting copolymerization. Because the molecular imprinted polymer is grafted on the surface of the matrix membrane without blocking the membrane pores, the resultant MIMs have high flux as microfiltration membrane (0.26 mol·m^-2·h^-1 of template and flux for distilled water was 3.6 ml·mim^-1·cm^-2 at 0.8 MPa). Moreover, the MIMs can absorb/desorb template molecules rapidly. Usually, it only takes several minutes for MIMs to absorb more than 75% of the template (adenine) in aqueous solution. And the influences of the type and amount of the functional monomers, the amount of the cross-linker on the absorption capability are discussed to determine the optimal preparation conditions。

Molecular imprinting of protein by coordinate interaction

在这篇文章，由形成在牛的浆液白朊(BSA ) 和铜离子之间的建筑群的一个新奇强壮的相互作用在水的答案为分子的印的水疗院胶化的准备被利用。结果证明在准备的铜离子的包括能一起衔接模板 BSA 和功能的单体并且与没有增加的铜离子，做的聚合物相比改进印的效果。高选择因素和大吸附能力也为获得的印 BSA 的水疗院胶化被观察。

Template-Monomer Interaction in Molecular Imprinting: Is the Strongest the Best?

Molecularly imprinted polymers (MIPs) represent a new class of materials possessing high selectivity and affinity for the target molecule. They have been utilized as sensors, catalysts, sorbents for solid-phase extraction, stationary phase for liquid chromatography, mimics of enzymes, receptors, and antibodies. In this research, molecular imprinted polymers (MIPs) for luteolin were prepared using acrylamide, 4-vinylpyridine and 1-allyl-piperazine as functional monomers and ethylene glycol dimethacrylate as cross-linker by non-covalent imprinting method. UV-visible spectra were used to evaluate the interaction strength between the template and the monomers. The composites of the polymers were calculated from elementary analysis. The porous properties of the imprinted polymers have been determined from nitrogen adsorption-desorption isotherms. The imprinting efficiency of the prepared MIPs was evaluated by selective adsorption for luteolin and its structural analogues. Although the interaction strength of monomers to the template was in the order 1-ALPP > 4-VP > AA, the binding affinity of the imprinted polymers towards luteolin was in the order MIP 2 > MIP 3 > MIP 1. Our results demonstrated that the imprinting efficiency was depending not only on the interaction strength between the template and the monomer, but also on the fidelity in transferring the complex into the polymer.

MOLECULAR IMPRINTED POLYMERS——Novel Polymer Adsorbents

Molecular imprinted polymers (MIPs) are novel functional polymer materials and known as specific adsorbents for the template molecules. These novel functional polymers have promised potential applications in racemic resolution, sensor, chromatography, adsorptive separation and other fields. This review exhibits the approach for preparing MIPs, the features of MIPs obtained by different routes and the characteristics of adsorptive separations with MIPs. The molecular recognition mechanism and the idea of the present possibilities and limitations of molecular imprinting polymerization are discussed as well.

Efficient removal of polybrominated diphenyl ethers from soil washing effluent by dummy molecular imprinted adsorbents: Selectivity and mechanisms

Surfactant enhanced elution is an effective method for removing hydrophobic organic pollutants from soils.The key to the development of leaching technology is selective removal of targeted pollutants in soil washing effluent and recycling of surfactant solutions.In this study,a molecular imprinting technique was applied to selectively sorb polybrominated diphenyl ethers(PBDEs)in soil washing effluent.The novel molecular imprinted polymers(MIPs)using different template molecules were synthesized by precipitation polymerization.Adsorption behaviors andmechanisms ofMIPs were studied through experiments and theoretical calculations.The results show that 4-bromo-4'-hydroxybiphenyl and toluene can be effective imprinting molecule for MIPs synthesis.The maximal adsorption capacity of selected dummy molecular imprinted polymer(D1-MIP)was 1032.36μmol/g,and that of part molecular imprinted polymer(P-MIP)was 981.13μmol/g.Their imprinting factors in 5 PBDEs adsorption ranged from 2.13 to 5.88,the recovery percentage of Triton X-100 can reach 99.09%,confirming the feasibility of reusing surfactant.Various PBDEs could be removed by MIPs,and Quantitative Structure Property Relationship analysis revealed that PBDEs’molecular volume,planarity,polarity,and hydrophobicity have major influences on their adsorption performance.DFT calculation revealed that Van derWaals force and hydrogen bonding played important roles during selective adsorption.These results can provide effective theoretical guidance for surfactant enhanced soil elution in practical engineering applications.

A Novel Molecular Imprinted Polymers-Based Lateral Flow Strip for Sensitive Detection of Thiodiglycol

Traditional detection of thiodiglycol(TDG),a metabolic marker for sulfur mustard poisoning,requires not only professional operators,but also expensive reagents and large instruments.Herein,we developed a novel molecular imprinted polymers(MIPs)-based lateral flow assay(LFA)strategy for the quick,sensitive,and selective detection of TDG.Gold nanoparticles(Au NPs),MIPs,and metallothioneins(MTs)were respectively loaded on the conjugate pad,test line(T line)and control line(C line).After adding TDG,Au NPs on the conjugate pad reacted with TDG through the Au-S bond first.Then,under the action of capillary force,the conjugates of TDG and Au NPs were trapped by the MIPs as they traveled to the T line,and the residual Au NPs bound with the MTs on the C line,exhibiting two obvious red bands on T line and C line,respectively.In contrast,a single red band could be observed on C line without TDG.This method exhibited a wide linear range from 10.0 pg/m L to 10,000.0 ng/m L and its limit of detection(LOD)was as low as 0.41 pg/m L.This method was successfully utilized to detect TDG in human urine,presenting significant potential in the point-of-care testing of TDG in clinical samples of the sulfur mustard poisoning patients.

Selective removal of 2,4-dichlorophenoxyacetic acid from water by molecularly-imprinted amino-functionalized silica gel sorbent

A molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-dichlorophenoxyacetic acid （2,4-D） was prepared by a surface imprinting technique in combination with a sol-gel process. The 2,4-D-imprinted amino-functionalized silica sorbent was characterized by FT-IR, nitrogen adsorption and static adsorption experiments. The selectivity of the sorbent was investigated by a batch competitive binding experiment using an aqueous 2,4-D and 2,4-dichlorophenol （2,4-DCP） mixture or using an aqueous 2,4-D and 2,4- dichlorophenylacetic acid （DPAC） mixture. The largest selectivity coefficient for 2,4-D in the presence of 2,4-DCP was found to be over 18, the largest relative selectivity coefficient between 2,4-D and 2,4-DCP over 9. The static uptake capacity and selectivity coefficient of the 2,4-D-imprinted functionalized sorbent are higher than those of the non-imprinted sorbent. The imprinted functionalized silica gel sorbent offered a fast kinetics for the extraction/stripping of 2,4-D, 73% of binding capacity （200 mg/L 2,4-D onto 20 mg of imprinted sorbent） was obtained within 5 min and the adsorbed 2,4-D can be easily stripped by the mixture solution of ethanol and 6 mol/L HC1 （V：V =1：1）. In a test of five extraction/stripping cycles, the adsorption capacity of the sorbent was all above 93% of that of the fresh sorbent. Experimental result showed the potential of molecularly-imprinted amino-functionalized sorbent for selective removal of 2,4-D.

Determination of Parathion-methyl in Vegetables by Fluorescent-Labeled Molecular Imprinted Polymer

A novel sensor for the determination of parathion-methyl based on couple grafting of functional molecular imprinted polymers （MIPs） was fabricated which is developed by anchoring the MIP layer on surfaces of silica particles embedded CdSe quantum dots by surface imprinting technology. The synthesized molecular imprinted silica nanospheres （CdSe@SiO2@MIP） allow a high selectivity and sensitivity of parathion-methyl via fluorescence intensity decreasing when the MIP material rebinding the parathion-methyl molecule. Compared with the MIP fabri- cated in traditional method, the template of parathion-methyl was easier to remove from the CdSe@SiO2@MIP imprinted material. Under optimal conditions, the fluorescence intensity of parathion-methyl at the imprinted sensor was detected by spectrofluorophotometer. The relative fluorescence intensity of CdSe@SiO2@MIP decreased linearly with the increasing concentration of parathion-methyl ranging from 0.013 mg·kg^-1 to 2.63mg·kg^-1 with a detection limit （3σ） of 0.004 mg·kg^-1 （S/N=3）, which is lower than the MIP in tradition. The imprinted film sensor was applied to detect parathion-methyl in vegetable samples without the interference of other organophosphate pesticides and showed a prosperous application in the field of food safety.

Solid-phase Extraction of β-Sitosterol from Oldenlandia diffusa Using Molecular Imprinting Polymer

The β-sitosterol imprinted polymer was prepared for selective extraction and analysis of β-sitosterol from Old-enlandia diffusa （0. diffusa） followed by HPLC with UV detection. The imprinted polymers show high affinity and selectivity to β-sitosterol. Using this molecularly imprinted polymer （MIP） cartridge as solid-phase extraction （SPE） material, the interferences could be quickly washed out and β-sitosterol was selectively retained and enriched. HPLC analysis method was used to evaluate the characteristics of this MIP material. At the condition of mobile phase composed of MeOH/H20/H3PO4 （99/1/0.1, V/V/V, pH=6.0） and the flow rate of 1.0 mL·min -1, a good linear relationship was demonstrated when the concentrations of β-sitosterol were in the range of 0.50--100.0 μg·mL-1. The recoveries ranged from 75.3% to 86.5% and the inter-day and intra-day relative standard deviations were less than 5%. This developed HPLC method was proved to be acceptable for extraction offl-sitosterol from O. diffusa.

Preparation of a PTE simulacrum based on surface molecular imprinting

Firstly,we synthesized N-methacryloyl-histidine monomer and N-methacryloyl-histidine-Cu^2＋ complex（MAH-Cu^2＋）.Then the molecular imprinting polymers（MIP） has been prepared by surface grafting on uniform polystyrene（PS） core using reversible addition-fragmentation transfer polymerization（RAFT） with MAH-Cu^2＋ as the functional monomer,methyl paraoxon as the template to simulate phosphodiesterase（PTE）.Finally,we have investigated the catalytic hydrolytic activities of MIP and non-imprinting polymers（NIP） to the template methyl paraoxon and the template analogue ethyl paraoxon respectively by UV spectrophotometry.The results showed that the catalytic hydrolytic activity of MIP to the template methyl paraoxon was highest and the value of k is 8.67×10^-5 mmol L^-1 min^-1,3.89-fold higher than MIP to the template analogue ethyl paraoxon,2.79-fold higher than NIP to the template methyl paraoxon.The KM,rm of MSP are also determined,and KM = 3.95×10^-4）mol/L,rm = 2.12μmol/ min.The MIP can be reused with only lose 7%of catalytic activity for four cycles.

Polypropylene non-woven supported fibronectin molecular imprinted calcium alginate/polyacrylamide hydrogel film for cell adhesion

Fibronectin （FN） imprinted polypropylene （PP） non-woven supported calcium alginate/polyacrylamide hydrogel film （PP-s-CA/PAM MIP） was prepared using non-woven PP fiber as matrix, FN as template molecule, sodium alginate （SA） and acrylamide （AM） as functional monomers, via UV radiation-reduced polymerization. The PP-s-CA[PAM MIP exhibited an obvious improvement in terms of adsorption capacity for FN compared with non-imprinted polymer （NIP）. The PP-s-CA/PAM MIP was successfully used for the culture of mouse fibroblast cells （L929） and the results showed that PP-s-CA]PAM MIP exhibited better cell adherence performance than the NIP did.