• Bulletin of the Korean Chemical Society
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• 제25권3호
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• pp.357-360
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• 2004

We developed in the present study molecular imprinted polymers (MIPs), using single templates (pentoxifylline, caffeine and theophylline) and mixed-templates (pentoxifylline-caffeine, pentoxifylline-theophylline and caffeine-theophylline). The MIPs were prepared with methacrylic acid (MAA) as the monomer, ethylene glycol dimetharylate (EGDMA) as the crosslinker and 2,2'-azobis(isobutyronitrile) (AIBN) as the initiator. The obtained polymer particles (particle size after grinding was about 25-35 ${\mu}$m) were packed into a HPLC column (3.9 mm i.d. ${\times}$ 150 mm). The selectivity and chromatographic characteristics of the MIPs were studied using acetonitrile as the mobile phase at a flow rate of 0.8 mL/min. UV detector wavelength was set at 270 nm. Different single template MIPs showed different molecular recognitions to the templates and the structurally analogues, according to the rigidity and steric hindrance of the compounds. Recognition was improved on the mixed-template MIPs as a result of the cooperation or sum effect of the templates, whereas on the pentoxifylline-theophylline imprinted polymer, the highest selectivity and affinity were obtained. Separations of the test compounds on different polymers were also investigated.

• KSBB Journal
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• 제18권1호
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• pp.65-69
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• 2003

Pentoxifylline MIPs에서 시료와 기능성 단위체 사이에는 수소결합이 형성되었다. 수소결합의 능력은 분자구조상 질소원자의 위치에 의해 결정되어졌다. Pentoxifylline과 caffeine theophylline MIPs 모두는 구조상 유사한 시료들과 affinity가 증가하는 결과를 얻어냈다. 특히 caffiene-theophylline MIPs에서 높은 수치의 체류인자와 IF를 얻었다. 이러한 결과로 적합한 복합 주형분자를 사용할 때 우리가 원하는 목적시료만을 선택적으로 분리 할 수 있고 그러므로 solid phase extraction에 사용되기에 적합하다는 결과를 얻어냈다.

• Macromolecular Research
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• 제14권3호
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• pp.324-330
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• 2006

Four different molecularly imprinted polymers (MIPs) were prepared using resveratrol as the template, methacrylic acid (MAA) or acrylamide (AA) as functional monomers, 2,2-azobisisobutyronitrile (AIBN) as the initiator, and thermo- or photo-induced polymerization. The ability of the different polymers to rebind selectively not only the template but also other phenols was evaluated. In parallel, the influence of the different templates and functional monomers used during polymer syntheses on the performance of the obtained MIPs was also studied through different rebinding experiments. The binding ability and selectivity of the polymer were studied by static balance method and Scatchard analysis. It was concluded that AA-based polymer by photo-induced polymerization presents the best properties to be used as a selective absorbent for the extraction of resveratrol.

• 폴리머
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• 제37권3호
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• pp.288-293
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• 2013

A group of molecularly imprinted polymers (MIPs) with specific recognition for chiral (S)-ibuprofen were successfully prepared based on hydrogen bonds, utilizing ${\alpha}$-methacrylic acid as a functional monomer. The IR analysis of MIPs showed that the blue- and red-shifted hydrogen bonds were formed between templates and functional monomers in the process of self-assembly imprinting and re-recognition, respectively. According to UV-Vis analysis, we found that the ratio of host-guest complexes between template molecule and functional monomer was 1:1. The effect of cross-linker's quantity on the polymerization was studied by transmission electron microscope (TEM). The adsorption selectivity experiments indicated that MIPs exhibited higher selectivity to (S)-ibuprofen than those to ketoprofen and (R)-ibuprofen, (S)-ibuprofen's structural analogs.

• KSBB Journal
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• 제14권3호
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• pp.273-278
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• 1999

The molecularly imprinted polymers(MIPs) synthesized at various polymerization conditions were examined as ibuprofen receptors in terms of binding characteristics. The 4-vinylpyridine polymers had 1.2 times higher adsorption capability for (S)-(+)-ibuprofen than the methacrylic acid polymers. The methacrylic acid polymers synthesized by UV radiation had 1.9 times higher selectivity for (S)-(+)-ibuprofen compared to those by thermal initiation. Effects of various solvents for binding were also examined in this research. According to the Scatchard analysis, the (S)-(+)-ibuprofen artificial receptors had two different kinds of binding sites for (S)-(+)-ibuprofen while having only single kind of binding site for ketoprofen. The binding sites of (S)-(+)-ibuprofen, n were calculated as 4.3~4.9 $\mu$mol/g and the dissociation constants, $K_D$ were 0.68 mM for the specific binding.

• KSBB Journal
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• 제16권2호
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• pp.115-122
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• 2001

Molecular imprinting has now been established as a technique which allows the creation of tailor-made binding sites for many classes of compounds. MIPs were prepared by covalent and non-covalent chemical bonding systems, by interactions between functional monomer and template. The shape of MIP is divided to particle and membrane. MIP membranes can be prepared by surface imprinting, in-situ polymerization, wet phase inversion and the dry phase inversion method. MIPs have been mainly used for analytical separation and biosensor systems to separate and detect chiral compounds and materials with similar structures. However the application of MIP by the chemical industries is still in its infancy stages. This review summarizes the preparative characteristics and applications of MIP with respect to chiral separations and biosensors.

• Macromolecular Research
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• 제10권2호
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• pp.122-126
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• 2002

A molecularly imprinted polymer (MIP) having both amidine and imidazole functional groups in the active site has been prepared using p-nitrophenyl phosphate as a transition state analogue (TSA). The imprinted polymer MIP with amidine and imidazole found to have the highest hydrolysis activity compared with other MIPs with either amidine or imidazole groups only. It is postulated a cooperative effect between amidine and imidazole in the hydrolysis of p-nitrophenyl methyl carbonate (NPMC) as a substrate when both groups were arranged in proximity by molecular imprinting. The rate enhancement of the hydrolysis by MIP was 60 folds over the uncatalyzed solution reaction and two folds compared with the control non-imprinted polymer CPI having both functional groups. The enzyme-mimetic catalytic hydrolysis of p-nitrophenyl acetate by MIP was evaluated in buffer at pH 7.0 with $K_{m}$ of 1.06 mM and $k_{cat}$ of 0.137 $h^{-1}$ . . .

• Journal of Electrochemical Science and Technology
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• 제14권1호
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• pp.1-14
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• 2023

The overuse of pesticides in agricultural sectors exposes people to food contamination. Pesticides are toxic to humans and can have both acute and chronic health effects. To protect food consumers from the adverse effects of pesticides, a rapid monitoring system of the residues is in dire need. Molecularly imprinted polymer (MIP) on a screen-printed electrode (SPE) is a leading and promising electrochemical sensing approach for the detection of several residues including pesticides. Despite the huge development in analytical instrumentation developed for contaminant detection in recent years such as HPLC and GC/MS, these conventional techniques are time-consuming and labor-intensive. Additionally, the imprinted SPE detection system offers a simple portable setup where all electrodes are integrated into a single strip, and a more affordable approach compared to MIP attached to traditional rod electrodes. Recently, numerous reviews have been published on the production and sensing applications of MIPs however, the research field lacks reviews on the use of MIPs on electrochemical sensors utilizing the SPE technology. This paper presents a distinguished overview of the MIP technique used on bare and modified SPEs for the detection of pesticides from four recent publications which are malathion, chlorpyrifos, paraoxon and cyhexatin. Different molecular imprint routes were used to prepare these biomimetic sensors including solution polymerization, thermal polymerization, and electropolymerization. The unique characteristics of each MIP-modified SPE are discussed and the comparison among the findings of the papers is critically reviewed.

• KSBB Journal
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• 제20권4호
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• pp.260-265
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• 2005

N-CBZ-L-phenylalanine를 주형분자로 하고 MAA와 4-VPY를 기능성 단량체로 하여 분자각인 고분자를 합성하였다. N-CBZ-L-phenylalanine와 MAA, 4-VPY는 수소결합의 영향을 많이 받고 있으며 이온결합과 소수성결합도 작용하고 있다. 혼합성분을 기능성 단량체로 사용함으로 하여 단량체의 성분들 사이에서 상호작용 효과를 나타냈다. 실험결과에 의하면 혼합 성분인 MAA와 4-VPY를 기능성 단량체로 한 분자각인 고분자에서의 체류인자가 단일성분인 MAA를 사용한 고분자에서의 체류인자보다 컸고 컬럼 효율은 낮았지만 분리도는 높았다. 산성인 MAA와 염기성인 4-VPY를 함께 사용함으로써 거울상 이성질체인 N-CBZ-L-phenylalanine과 N-CBZ-D- phenylalanine의 분리도를 증가시킬 수 있었다. 혼합된 성분의 기능성 단량체로하여 제조된 분자각인 고분자를 키랄 물질의 분리를 비롯한 천연물질의 분리에 더 광범위하게 사용될 수 있을 것이다.