An Ion-imprinted Silica Gel Polymer Prepared by Surface Imprinting Technique Combined with Aqueous Solution Polymerization for Selective Adsorption of Ni(Ⅱ) from Aqueous Solution

A novel Ni（Ⅱ） ion-imprinted silica gel polymer was prepared via the surface imprinting technique combined with aqueous solution polymerization by using 2-acrylamido-2-methyl-1-propanesulfonic acid（AMPS） as a functional monomer for the selective separation of Ni（Ⅱ） from aqueous solution. The sorbent showed good chemical and thermal stability. Kinetics studies indicated that the equilibrium adsorption was achieved within 10 min and the adsorption kinetics fitted well with the pseudo-second-order kinetic model. The maximum adsorption capacity of the ion-imprinted polymer towards Ni（Ⅱ） at the optimal p H of 7.0 was 66.22 mg·g^（-1）. The relative selectivity coefficients of the sorbent were 9.23, 15.71, 14.72 and 20.15 for Ni（Ⅱ）/Co（Ⅱ）, Ni（Ⅱ）/Cu（Ⅱ）, Ni（Ⅱ）/Zn（Ⅱ） and Ni（Ⅱ）/Pb（Ⅱ）, respectively. The adsorption isotherm fitted well with Langmuir isotherm model. The thermodynamic results indicated that the adsorption of Ni（Ⅱ） was a spontaneous and endothermic process. The sorbent showed good reusability evidenced by six cycles of adsorption/desorption experiments. The precision of this method is satisfactory. Thus, the prepared sorbent can be considered as a promising sorbent for selective separation of Ni（Ⅱ） in real water samples.

Preparation of quercetin imprinted core-shell organosilicate microspheres using surface imprinting technique

In this work,the quercetin imprinted core-shell microspheres were prepared using silica surface imprinting technique.A simple sol-gel procedure was used for the synthesis of the imprinted materials with 3-aminopropyltriethoxysilane as functional monomer and tetraethyl orthosilicate as crosslinker.The SEM images indicated that the MIPs shell was successfully grafted onto the silica surface.The characteristics of the molecularly imprinted polymers such as capacity,selectivity and absorption dynamic were investigated by rebinding experiments.The results showed that the prepared MIPs had good imprinting effect and adsorption amount of quercetin.

A novel surface molecularly imprinted polymer as the solid-phase extraction adsorbent for the selective determination of ampicillin sodium in milk and blood samples

Surface molecularly imprinted polymers （SMIPs） for selective adsorption of ampicillin sodium were synthesized using surface molecular imprinting technique with silica gel as a support. The physical and morphological characteristics of the polymers were investigated by scanning electron microscope （SEM）, Fourier transform infrared spectroscopy （FT-IR）, thermogravimetric analysis （TGA）, elemental analysis and nitrogen adsorption-desorption test. The obtained results showed that the SMIPs displayed great adsorption capacity （13.5 lag/mg）, high recognition ability （the imprinted factor is 3.2） and good binding kinetics for ampicillin sodium. Finally, as solid phase extraction adsorbents, the SMIPs coupled with HPLC method were validated and applied for the enrichment, purification and determination of anapicillin sodium in real milk and blood samples. The averages of spiked accuracy ranged from 92.1% to 107.6%. The relative standard deviations of intra- and inter-day precisions were less than 4.6%. This study provides a new and promising method for enriching, extracting and determining ampicillin sodium in complex biological samples.

SURFACE METAL ION-IMPRINTED RESINS PREPARED BY EMULSIFIER-FREE EMULSION POLYMERIZATION USING PHOSPHORIC DIESTER AS FUNCTIONAL MONOMER

The uniform surface ion-imprinted resins for Zn2+ as the imprinting guest were prepared by emulsifier-free emulsion polymerization utilizing ally phenyl hydrogenphosphate as a functional comonomer. The Zn2+-imprinted resin adsorbed Zn2+ much more effectively than did the unimprinted one. The selective feature of the surface imprinted resins to the template ions was demonstrated.

The Surface Imprinted Polystyrene Beads Prepared via Emulsion Templates

In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788), the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer, cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.

Synthesis,characterization,and performance comparison of boron using adsorbents based on N-methyl-D-glucosamine

Using N-methyl-D-glucosamine(NMDG)as the functional monomer,glycidyl methacrylate(GMA)as the connecting monomer,functionalized Fe3O4 nano-particles(NPs)as the support,three adsorbents were prepared including direct polymer GMA-NMDG,magnetic GMA-NMDG polymer(MGN),and boron magnetic ion-imprinted polymer(BMIIP).Based upon the optimization of synthesis conditions,the prepared adsorbents and intermediate products were characterized using Fourier transform infrared spectroscopy,thermogravimetric analysis,scanning electron microscope,energy dispersive spectroscopy,X-ray diffraction,vibrating sample magnetometer,and Brunauer–Emmett–Teller to investigate the synthesis process,the morphological structure and the functional properties of the materials.The optimum performances of GMA-NMDG,MGN and BMIIP were obtained in the initial neutral solution(pH of 6.5).Moreover,GMANMDG and MGN reached the maximum adsorption capacity at 120 min,whereas BMIIP reached adsorption saturation at 60 min.The pseudo-second-order kinetic model was more suitable for the adsorption of boron using the adsorbents.The maximum adsorption capacity of GMA-NMDG was found to be 43.4 mg·g^(-1),while those of MGN and BMIIP were 32.5 and 28.3 mg·g^(-1),respectively.The Langmuir isotherm model was more appropriate to describe the adsorption process.The adsorbents maintained satisfactory adsorption performance within a certain temperature range.Competing ions had little effect on the adsorption of boron,and would be adsorbed simultaneously,due to which,the effect of co-adsorption can be considered.The adsorption capacity of GMA-NMDG was high,while the adsorption selectivity of BMIIP was much better.Furthermore,BMIIP showed good adsorption after five cycles of adsorption and desorption.The comparison of adsorbents showed that GMA-NMDG had the highest adsorption capacity and was suitable for co-adsorption.MGN had a high adsorption capacity,good comprehensive performance and magnetic properties.BMIIP had better adsorption rate,adsorption selectivity and recyclability.Through the optimization of synthesis conditions,the adsorption capacity of the traditional monomer NMDG polymer was increased,and the magnetism was given to facilitate rapid recovery.Combined with the ion imprinting technology,it showed higher boron adsorption selectivity in the presence of competitive ions.

Molecularly Imprinted Polymers on Chloromethyl Polystyrene Resin Prepared via RAFT Polymerization

Surface molecularly imprinted polymers （SMIP） was prepared via the reversible addition-fragmentation chain transfer （RAFT） polymerization on the chloromethyl polystyrene resin （CPR） in the presence of the template D-phenylalanine. The structure of SMIP was characterized by FTIR and SEM. The adsorption behavior of D-phenylalanine of SMIP was preliminarily investigated.

Surface-imprinted polymers in microfluidic devices

Molecularly imprinted polymers are generated by curing a cross-linked polymer in the presence of a template. During the curing process, noncovalent bonds form between the polymer and the template. The interaction sites for the noncovalent bonds become "frozen" in the cross-linking polymer and maintain their shape even after the template is removed. The resulting cavities reproduce the size and shape of the template and can selectively reincorporate the template when a mixture containing it flows over the imprinted surface. In the last few decades the field of molecular imprinting has evolved from being able to selectively capture only small molecules to dealing with all kinds of samples. Molecularly imprinted polymers (MIPs) have been generated for analytes as diverse as metal ions, drug molecules, environmental pollutants, proteins and viruses to entire cells. We review here the relatively new field of surface imprinting, which creates imprints of large, biologically relevant templates. The traditional bulk imprinting, where a template is simply added to a prepolymer before curing, cannot be applied if the analyte is too large to diffuse from the cured polymer. Special methods must be used to generate binding sites only on a surface. Those techniques have solved crucial problems in separation science as well as chemical and biochemical sensing. The implementation of imprinted polymers into microfluidic chips has greatly improved the applicability of microfluidics. We present the latest advances and different approaches of surface imprinting and their applications for microfluidic devices.

Selective Adsorption of Co（II） by Mesoporous Silica SBA-15-Supported Surface Ion Imprinted Polymer： Kinetics, Isotherms, and Thermodynamics Studies

A novel surface ion implinted adsorbent [Co（II）-IIP] using polyethyleneimine （PEI） as function monomer and ordered mesoporous silica SBA-15 as support matrix was prepared for Co（II） analysis with high selectivity. The prepared polymer was characterized by Fourier transmission infrared spectrometry, scanning electron microscopy, X-ray diffraction and nitrogen adsorption-desorption isotherm. Bath experiments of Co（II） adsorption onto Co（II）-IIP were performed under the optimum conditions. The experimental data were analyzed by pseudo-first-order and pseudo-second-order kinetic models. It was found that the pseudo-second-order model best correlated the kinetic data. The intraparticle diffusion and liquid film diffusion were applied to discuss the adsorption mechanism. The results showed that Co（II） adsorption onto IIP was controlled by the intraparticle diffusion mechanism, along with a considerable film diffusion contribution. Langmuir, Freundlich and Dubinin-Radushkevich adsorption models were applied to determine the isotherm parameters. Langmuir model fitted the experiment data well and the maximum calculated capacity of Co（II） reached 39.26 mg/g under room temperature. The thermodynamic data were indicative of the spontaneousness of the endothermic sorption process of Co（II） onto Co（II）-IIP. Co（II）-IIP showed high affinity and selectivity for template ion compared with non imprinted polymer （NIP）.

Synthesis of surface imprinted polymers based on wrinkled flower-like magnetic graphene microspheres with favorable recognition ability for BSA

Nowadays,the employing of molecular imprinting technique in the analysis and separation of proteins from complex biological samples has been widely favored by researchers.To enrich the types of surface protein imprinted materials and expand the application fields of graphene materials,novel surface molecular imprinted polymers(MIPs)based on magnetic graphene microspheres Fe_(3)O_(4)@r GO@MIPs are first synthesized in this paper.Fe_(3)O_(4)@r GO@MIPs are prepared by oxidative self-polymerization of dopamine on the surface of magnetic graphene(Fe_(3)O_(4)@r GO)composite microspheres.Bovine serum albumin(BSA)is selected as protein template.Fe_(3)O_(4)@r GO microspheres with wrinkled flower-like structure are obtained by compounding Fe_(3)O_(4)and graphene oxide in an appropriate ratio via the method of high-temperature reduction self-assembly.The microspheres exhibit promising dispersibility,high external surface area,rich pore structure,and sufficient magnetic properties.These advantages not only prevent the agglomeration of imprinted microspheres in the aqueous phase,which is conducive to contact and static adsorption,but also increase the amount of protein imprinting.Additionally,sufficient magnetic properties ensure fast and effective separation of the adsorbents.While the adsorption capacity is increased,the separation procedure becomes simple.The binding capacity of Fe_(3)O_(4)@r GO@MIPs for BSA can reach 317.58 mg/g within 60 min,and the imprinting factor(IF)is 4.24.More importantly,Fe_(3)O_(4)@r GO@MIPs can specifically recognize the target BSA from the mixed proteins and the actual sample.There is no significant decrease in the adsorption amount,IF,and magnetic properties after eight runs.It is promising to be used in the separation of proteins from the actual biological samples.

Preliminary investigations into surface molecularly imprinted nanoparticles for Helicobacter pylori eradication

This paper reports investigations into the preparation and characterization of surface molecularly imprinted nanoparticles(SMINs) designed to adhere to Helicobacter pylori(H.pylori).Imprinted nanoparticles were prepared by the inverse microemulsion polymerization method.A fraction of Lpp20,an outer membrane protein of H.pylori known as NQA,was chosen as template and modified with myristic acid to facilitate its localization on the surface of the nanoparticles.The interaction between these SMINs with the template NQA were evaluated using surface plasmon resonance(SPR),change in zeta potential and fluorescence polarization(FP).The results were highly consistent in demonstrating a preferential recognition of the template NQA for SMINs compared with the control nanoparticles.In vitro experiments also indicate that such SMINs are able to adhere to H.pylori and may be useful for H.pylori eradication.

Detection of parathion methyl using a surface plasmon resonance sensor combined with molecularly imprinted films

An ultra-sensitive and highly selective parathion methyl （PM） detection method by surface plasmon resonance （SPR） combined with molecularly imprinted films （MIF） was developed. The PM-imprinted film was prepared by thermo initiated polymerization on the bare Au surface of an SPR sensor chip, Template PM molecules were quickly removed by an organic solution of acetonitrilelacetic acid （9：1, v/v）, causing a shift of 0.5° in SPR angle. In the concentrations range of 10^-13-10^-10 mol/L, the refractive index showed a gradual increase with higher concentrations of template PM and the changes of SPR angles were linear with the negative logarithm of PM concentrations. In the experiment, the minimum detectable concentration was 10^-13 mol/L. The selectivity of the thin PM-imprinted film against diuron, tetrachlorvinphose and fenitrothion was examined, but no observable binding was detected. The results in the experiment suggested that the MIF had the advantages of high sensitivity and selectivity.

Surface plasmon resonance sensor chips for the recognition of bovine serum albumin via electropolymerized molecularly imprinted polymers

In this paper, a surface plasmon resonance （SPR） sensor chip for detection of bovine serum album （BSA） was prepared by electropolymerization of 3-aminophenylboronic acid （3-APBA） based on molecularly imprinted polymer （MIP） technique. The surface morphology of MIP and non-imprinted （NIP） films were characterized by scanning electroscopy （SEM）. SEM images exhibited nanoscale cavities formed on the MIP films surface homogeneously due to the removal of BSA templates. The effects of pH, ion strength of rebinding BSA, the specific binding and selective recognition were studied for MIP films. Results indicated that the BSA-imprinted films exhibited a good adsorption of template protein （0.02-0.8 mg/mL） in 0.05 mol/L sodium phosphate buffer at pH 5.0 with the limit of detection （LOD） of 0.02 mg/mL.

Surface molecularly imprinted polymers for solid-phase extraction of （-）-epigallocatechin gallate from toothpaste

Surface molecularly imprinted polymers （SMIPs） have been synthesized to selectively determine （-）-epigallocatechin gallate in aqueous media. SMIPs were prepared using a surface grafting copolymerization method on a functionalized silica gel modified with β-cyclodextrin and vinyl groups. The morphology and composition of the SMIPs were investigated by scanning electron microscopy, Fourier transform-infrared spectroscopy and thermogravimetric analysis. In addition, the molecular binding capacity, recognition properties and selectivity of the SMIPs were evaluated. The imprinted polymers were found to have a highly specific recognition and binding capacity for aqueous media which is （-）-epigallocatechin gallate in the result of the hydrophobic properties of the β-cyclodextrin and the hydrogen-bonding interactions of methacrylic acid. The SMIPs were successfully employed as solid-phase extraction adsor- bents prior to the HPLC determination of （-）-epigallocatechin gallate in toothpaste. The HPLC analysis had a linear dynamic range of 0.5-50.0 μg·mL^-1 with a correlation coefficient of 0.9998 and the recoveries ranged from 89.4% to 97.0% with relative standard deviations less than 4.8%. The limit of detection and limit of quantification were 0.17 and 0.33 μg·mL^-1, respectively. The method provides a promising approach for the preparation of selective materials for the purification and determination of complex samples.