scholarly journals Recognizing Amino Acid Chirality with Surface-Imprinted Polymers Prepared in W/O Emulsions

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Min Jae Shin ◽  
Young Jae Shin ◽  
Seung Won Hwang ◽  
Jae Sup Shin

A molecularly imprinted polymer was prepared by a surface molecular imprinting technique in water-in-oil (W/O) emulsion. In this technique, the solid polymer, which is molecularly imprinted at the internal cavity surface, is prepared by polymerizing W/O emulsions consisting of a water-soluble imprinted molecule, a functional host molecule, an emulsion stabilizer, and a crosslinking agent. Dioleoyl phosphate was used as an emulsion stabilizer, and this compound also acted as a monomer and a host functional group in the imprinted cavity. Divinylbenzene was used as a crosslinker. Tryptophan methyl ester and phenylalanine methyl ester were used as the target template materials. These imprinted polymers exhibited enantiomeric selectivity in absorption experiments, and the maximum separation factor was 1.58. The enantiomeric selectivity with tryptophan methyl ester was higher than that with phenylalanine methyl ester.

Sensors ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 296
Author(s):  
Mashaalah Zarejousheghani ◽  
Alaa Jaafar ◽  
Hendrik Wollmerstaedt ◽  
Parvaneh Rahimi ◽  
Helko Borsdorf ◽  
...  

Molecularly imprinted polymers have emerged as cost-effective and rugged artificial selective sorbents for combination with different sensors. In this study, quaternary ammonium cations, as functional monomers, were systematically evaluated to design imprinted polymers for glyphosate as an important model compound for electrically charged and highly water-soluble chemical compounds. To this aim, a small pool of monomers were used including (3-acrylamidopropyl)trimethylammonium chloride, [2-(acryloyloxy)ethyl]trimethylammonium chloride, and diallyldimethylammonium chloride. The simultaneous interactions between three positively charged monomers and glyphosate were preliminary evaluated using statistical design of the experiment method. Afterwards, different polymers were synthesized at the gold surface of the quartz crystal microbalance sensor using optimized and not optimized glyphosate-monomers ratios. All synthesized polymers were characterized using atomic force microscopy, contact angle, Fourier-transform infrared, and X-ray photoelectron spectroscopy. Evaluated functional monomers showed promise as highly efficient functional monomers, when they are used together and at the optimized ratio, as predicted by the statistical method. Obtained results from the modified sensors were used to develop a simple model describing the binding characteristics at the surface of the different synthesized polymers. This model helps to develop new synthesis strategies for rational design of the highly selective imprinted polymers and to use as a sensing platform for water soluble and polar targets.


2008 ◽  
Vol 1138 ◽  
Author(s):  
Zhan Liu ◽  
David G. Bucknall ◽  
Mark G. Allen

AbstractThis work presents the study on the recognition and absorption of the water-soluble X-ray contrast medium iodixanol in aqueous solution using synthetic molecularly imprinted polymers (MIPs). A non-covalent imprinting technique was applied to prepare iodixanol-imprinted polymers using 4-vinylpyridine as the functional monomer and ethylene glycol dimethacrylate as the cross-linker. The effects of quantity of iodixanol templates, the crosslink density, and the solvent were studied in terms of the binding capacity and imprint effect of the polymers. UV-vis spectrometric analysis shows that the highest binding capacity achieved is 284 mg iodixanol per gram of dry polymer, which is 8.8 times higher than the binding capacity of the non-imprinted control polymers (NIPs). SEM and BET surface analysis have also been performed to investigate the effect of morphology and porosity on the binding capacities of polymers.


2019 ◽  
Vol 2019 ◽  
pp. 1-12
Author(s):  
Shanwen Zhao ◽  
Chanling Wei ◽  
Zhian Sun ◽  
Huachun Liu ◽  
Yanqiang Zhou ◽  
...  

Chloramphenicol- (CAP-) restricted access media-molecularly imprinted polymers (CAP-RAM-MIPs) were prepared by precipitation polymerization using CAP as a template molecule, 2-diethylaminoethyl methacrylate (DEAEM) as a functional monomer, ethylene glycol dimethyl acrylate (EDMA) as a crosslinking agent, glycidyl methacrylate (GMA) as an outer hydrophilic functional monomer, and acetonitrile as a pore former and solvent. The CAP-RAM-MIPs were successfully characterized by Fourier-transform infrared spectroscopy, scanning electron microscopy, and thermogravimetric analysis. The adsorption performance was investigated in detail using static, dynamic, and selective adsorption experiments. Adsorption equilibrium could be reached within 11 min. The CAP-RAM-MIPs had a high adsorption rate and good specific adsorption properties. Scatchard fitting curves indicated there were two binding sites for CAP-RAM-MIPs. Adsorption was Freundlich multilayer adsorption and consistent with the quasi-second kinetic model. Using CAP-RAM-MIPs for selective separation and enrichment CAP in bovine serum in combination with high-performance liquid chromatography (HPLC), CAP recovery ranged from 94.1 to 97.9% with relative standard deviations of 0.7–1.5%. This material has broad application prospects in enrichment and separation.


1972 ◽  
Vol 126 (3) ◽  
pp. 645-657 ◽  
Author(s):  
T. N. Pattabiraman ◽  
W. B. Lawson

A series of arylalkanoate esters and α-acetamidoarylalkanoate esters were tested as substrates for α-chymotrypsin and subtilisin BPN′. Chymotrypsin hydrolysed N-acetyl-l-phenylalanine methyl ester and methyl 4-phenylbutyrate faster than their respective higher and lower homologues, whereas methyl 2-acetamido-6-phenylhexanoate and methyl 6-phenylhexanoate were better substrates for subtilisin than their lower homologues. N-Acetyl-l-tryptophan methyl ester and its analogue, N-acetyl-3-(1-naphthyl)-alanine methyl ester, were hydrolysed 23 times faster by chymotrypsin than by subtilisin. These results indicate that the binding site of α-chymotrypsin is roughly 1.1nm (11Å) long and curved, whereas that of subtilisin is a longer system and less curved. The stereo-specificity during the hydrolysis of typical substrates by both enzymes was found to vary over a wide range. The enhancing effect of the α-acetamido group in the l-series of substrates and the detrimental effect in the d-series of substrates also varies considerably.


2014 ◽  
Vol 1030-1032 ◽  
pp. 112-115 ◽  
Author(s):  
Yan Zhou ◽  
Zheng Ping Wang ◽  
Pan Pan Guo ◽  
Xue Gao

Magnetic molecularly imprinted polymers (MMIPs) based on poly [2,2’-(p-oxidiphenylene)-5,5’-bibenzimidazole] (OPBI) composites were synthesized for the selective adsorption and detection of nonylphenol (NP) from water samples. During polymerization, Fe3O4@C was used as supporter and magnetic substance and OPBI not only was used as crosslinking agent but also functional monomer. Morphology of Fe3O4@C and MMIPs were investigated by scanning electron microscopy (SEM). The kinetics of adsorption followed the pseudo-first-order model. Selectivity of MMIPs was further demonstrated through HPLC analysis of the water samples, in which bisphenol A (BPA), phenol, 4-nitrophenol (4-NP) and tetrabromobisphenol (TBBPA) were dissolved respectively. The result showed that MMIPs had more effectively recognition capability of NP than other contrasts.


2005 ◽  
Vol 382 (7) ◽  
pp. 1698-1701 ◽  
Author(s):  
Takuya Kubo ◽  
Ken Hosoya ◽  
Makoto Nomachi ◽  
Nobuo Tanaka ◽  
Kunimitsu Kaya

2021 ◽  
Vol 73 (1) ◽  
pp. 103-118
Author(s):  
T.K. Jumadilov ◽  
◽  
R.G. Kondaurov ◽  
A.M. Imangazy ◽  
Kh. Khimersen ◽  
...  

Molecularly imprinted polymers (MIPs) based on methacrylic acid (MAA) and 4-vinylpyridine (4VP) of two types have been synthesized (the difference in types is based on the use of ethylene glycol dimethacrylate (EGDMA) and diethylene glycol dimethacrylate (DEGDMA) as a crosslinking agent). Salts of cerium, praseodymium, neodymium, samarium, and europium were used as templates for the synthesis. Control samples of Molecularly imprinted polymers were also synthesized (samples synthesized in exactly the same way, but without the templates).Electrochemical and conformational behavior of the synthesized structures in an aqueous medium was studied. Molecularly imprinted polymers are weakly exposed to swelling and ionization due to tight crosslinking, while it should be noted that a high degree of crosslinking leads to high mechanical strength of macromolecular structures.Comparison of the measured parameters (electrical conductivity, pH) of molecularly imprinted polymers containing a template with control samples of MIP indicate the presence of cavities complementary to the template (rare-earth metal ion) used in their synthesis. In the presence of MIP synthesized in the presence of EGDMA (MIP-1) higher values of electrical conductivity and pH are observed as compared to MIP synthesized in the presence of DEGDMA (MIP-2) due to less tight crosslinking.


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