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Nischang I, Brüggemann O, Teasdale I. Facile, Single-Step Preparation of Versatile, High-Surface-Area, Hierarchically Structured Hybrid Materials. Angew Chem Int Ed Engl 2011. [DOI: 10.1002/ange.201100971] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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Teasdale I, Wilfert S, Nischang I, Brüggemann O. Multifunctional and biodegradable polyphosphazenes for use as macromolecular anti-cancer drug carriers. Polym Chem 2011. [DOI: 10.1039/c0py00321b] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Nischang I, Teasdale I, Brüggemann O. Porous polymer monoliths for small molecule separations: advancements and limitations. Anal Bioanal Chem 2010; 400:2289-304. [DOI: 10.1007/s00216-010-4579-6] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 12/02/2010] [Indexed: 12/19/2022]
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Nischang I, Teasdale I, Brüggemann O. Towards porous polymer monoliths for the efficient, retention-independent performance in the isocratic separation of small molecules by means of nano-liquid chromatography. J Chromatogr A 2010; 1217:7514-22. [DOI: 10.1016/j.chroma.2010.09.077] [Citation(s) in RCA: 90] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 09/25/2010] [Accepted: 09/28/2010] [Indexed: 11/28/2022]
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Nischang I, Brüggemann O. On the separation of small molecules by means of nano-liquid chromatography with methacrylate-based macroporous polymer monoliths. J Chromatogr A 2010; 1217:5389-97. [DOI: 10.1016/j.chroma.2010.06.021] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2010] [Revised: 06/02/2010] [Accepted: 06/08/2010] [Indexed: 11/16/2022]
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Volkmann A, Brüggemann O. Catalysis of an ester hydrolysis applying molecularly imprinted polymer shells based on an immobilised chiral template. REACT FUNCT POLYM 2006. [DOI: 10.1016/j.reactfunctpolym.2006.07.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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57
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Visnjevski A, Schomäcker R, Yilmaz E, Brüggemann O. Erratum to “Catalysis of a Diels-Alder cycloaddition with differently fabricated molecularly imprinted polymers” [Catal. Commun. 6 (9) (2005) 601–606]. CATAL COMMUN 2006. [DOI: 10.1016/j.catcom.2005.08.004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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58
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Kalim R, Schomäcker R, Yüce S, Brüggemann O. Catalysis of a β-elimination applying membranes with incorporated molecularly imprinted polymer particles. Polym Bull (Berl) 2005. [DOI: 10.1007/s00289-005-0438-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Visnjevski A, Schomäcker R, Yilmaz E, Brüggemann O. Catalysis of a Diels-Alder cycloaddition with differently fabricated molecularly imprinted polymers. CATAL COMMUN 2005. [DOI: 10.1016/j.catcom.2005.06.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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El-Toufaili FA, Visnjevski A, Brüggemann O. Screening combinatorial libraries of molecularly imprinted polymer films casted on membranes in single-use membrane modules. J Chromatogr B Analyt Technol Biomed Life Sci 2004; 804:135-9. [PMID: 15093167 DOI: 10.1016/j.jchromb.2004.02.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
A new and fast technique for screening combinatorial libraries of molecularly imprinted polymers is presented. The procedure is based on commercially available membrane modules which are rinsed with pre-polymerization imprinting mixtures. After the in situ polymerization and generation of MIP films on the PTFE membranes within the modules, the membranes are evaluated in terms of affinity towards the target molecule (template) R-(-)-phenylbutyric acid. Therefore, after template extraction from the freshly produced membranes a solution of this target molecule is flushed through the module. By analyzing the remaining analyte concentration in the permeate, the amount of analyte adsorbed on the membrane can be calculated and related to specific interactions with the molecular imprints. By this means, optimized recipes in terms of cross-linker to template ratios could be obtained in combination with the optimal porogen, when screening p-divinylbenzene or ethylene glycol dimethacrylate as cross-linker and porogens like acetonitrile, dimethylsulfoxide and methanol.
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Brüggemann O, Visnjevski A, Burch R, Patel P. Selective extraction of antioxidants with molecularly imprinted polymers. Anal Chim Acta 2004. [DOI: 10.1016/j.aca.2003.08.033] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Brüggemann O. Molecularly imprinted materials--receptors more durable than nature can provide. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2002; 76:127-63. [PMID: 12126267 DOI: 10.1007/3-540-45345-8_4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/25/2023]
Abstract
The chapter describes the concept of molecular imprinting. This technology allows the fabrication of artificial polymeric receptors applicable in many areas of biotechnology. Polymers imprinted with selected template molecules can be used as specific recognition elements in sensors or as selective stationary phases in affinity chromatography or in capillary electrochromatography. However, also in solid phase extraction or immunoassays these polymers (MIP) are able to compete with traditional materials such as biological antibodies. Furthermore, polymers molecularly imprinted with so-called transition state analogue templates can be applied as catalysts. In other words, these kind of polymers may be used as artificial antibodies (plastibodies) or biomimicking enzymes (plastizymes). Compared to their biological counterparts, MIP offer different advantages such as simplicity in manufacturing and durability. Thus, the author expects MIP to have a major impact on the whole area of biotechnology.
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Brüggemann O. Catalytically active polymers obtained by molecular imprinting and their application in chemical reaction engineering. BIOMOLECULAR ENGINEERING 2001; 18:1-7. [PMID: 11429307 DOI: 10.1016/s1389-0344(01)00076-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Molecular imprinting is a way of creating polymers bearing artificial receptors. It allows the fabrication of highly selective plastics by polymerizing monomers in the presence of a template. This technique primarily had been developed for the generation of biomimetic materials to be used in chromatographic separation, in extraction approaches and in sensors and assays. Beyond these applications, in the past few years molecular imprinting has become a tool for producing new kinds of catalysts. For catalytic applications, the template must be chosen, so that it is structurally comparable with the transition state (a transition state analogue, TSA) of a reaction, or with the product or substrate. The advantage of using these polymeric catalysts is obvious: the backbone withstands more aggressive conditions than a bio material could ever survive. Results are presented showing the applicability of a molecularly imprinted catalyst in different kinds of chemical reactors. It is demonstrated that the catalysts can be utilized not only in batch but also in continuously driven reactors and that their performance can be improved by means of chemical reaction engineering.
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Ramström O, Skudar K, Haines J, Patel P, Brüggemann O. Food analyses using molecularly imprinted polymers. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2001; 49:2105-2114. [PMID: 11368563 DOI: 10.1021/jf001444h] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Molecular imprinting technology (MIT) is a technique for generating polymers bearing biomimetic receptors. It offers several advantages to the agrofood industry in areas such as analysis, sensoring, extraction, or preconcentration of components. It has the potential of becoming a tool for acquiring truly simple, rapid, and robust direct measurements. In this review, the special features of MIT that have bearing on food science and technology are highlighted.
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Brüggemann O. Untersuchung katalytisch aktiver, molekular geprägter Polymere unter Aspekten der chemischen Reaktionstechnik. CHEM-ING-TECH 2001. [DOI: 10.1002/1522-2640(200104)73:4<373::aid-cite373>3.0.co;2-b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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Brüggemann O, Haupt K, Ye L, Yilmaz E, Mosbach K. New configurations and applications of molecularly imprinted polymers. J Chromatogr A 2000; 889:15-24. [PMID: 10985531 DOI: 10.1016/s0021-9673(00)00350-2] [Citation(s) in RCA: 132] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Molecularly imprinted polymers (MIPs) are applicable in a variety of different configurations. For example, bulk polymers imprinted with beta-lactam antibiotics are presented to be used as stationary phases for the chromatographic separation of beta-lactam antibiotics with both aqueous and organic mobile phases. However, in some analytical applications, monosized spherical beads are preferred over the currently used ground bulk polymers. A precipitation polymerization technique allows preparation of monosized spherical imprinted beads with diameters down to 200 nm having excellent recognition properties for different target molecules. Nevertheless, with current imprinting protocols a substantial amount of template has to be used to prepare the polymer. This can be problematic if the template is poorly soluble, expensive or difficult to obtain. It is shown that for analytical applications, the functional monomer:template ratio can be drastically increased without jeopardizing the polymer's recognition properties. Furthermore, a substantial reduction of the degree of crosslinking is demonstrated, resulting in much more flexible polymers that are useful for example the preparation of thin imprinted films and membranes for sensors. Apart from analysis, MIPs also are applicable in chemical or enzymatic synthesis. For example, MIPs using the product of an enzyme reaction as template are utilized for assisting the synthetic reaction by continuously removing the product from the bulk solution by complexation. This results in an equilibrium shift towards product formation.
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Skudar K, Brüggemann O, Wittelsberger A, Ramström O. Selective recognition and separation of β-lactam antibiotics using molecularly imprinted polymers. ACTA ACUST UNITED AC 1999. [DOI: 10.1039/a905151a] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Abstract
Endotoxins are part of the outer membrane of gram-negative bacteria such as E. coli. Upon entering the blood stream, they cause a violent, sometimes life-threatening, response of the immune system. Endotoxins are lipopolysaccharides (LPS), lacking optically active groups, and their detection in the underivatized state can be difficult. In this paper the potential of capillary electrophoresis (CE) for LPS analysis is investigated. By using a standard phosphate buffer method, concentrations down to 100 micrograms/mL can be detected within 6 min. The detection limit can be lowered by one order of magnitude by using a sodium dodecyl sulfate (SDS)/borate buffer, pH 9.2. In this buffer, the SDS serves to homogenize the size of the LPS aggregates, while the borate forms complexes with the diol groups of the molecule, thereby enhancing its optical activity. The formation of LPS-affinity complexes with the UV-active polymyxin B or labeling of the LPS with a fluorophore (fluorescein isothiocyanate) was unsuccessful. Best results, in terms of detection limit and speed, were obtained with an indirect UV-detection CE method. By using a strongly UV-active electrophoresis buffer, endotoxins could be detected as "negative" peaks. In this case, a detection limit of 3 micrograms/mL (35 pM) was determined. Proteins and other UV-active substances did not disturb the assay, since they generated no detectable signals. The indirect UV detection was used to quantify the residual LPS content of a DNA preparation from E. coli.
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Brüggemann O, Freitag R, Whitcombe MJ, Vulfson EN. Comparison of polymer coatings of capillaries for capillary electrophoresis with respect to their applicability to molecular imprinting and electrochromatography. J Chromatogr A 1997. [DOI: 10.1016/s0021-9673(97)00288-4] [Citation(s) in RCA: 116] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Brüggemann O, Meder M, Freitag R. Analysis of amatoxins alpha-amanitin and beta-amanitin in toadstool extracts and body fluids by capillary zone electrophoresis with photodiode array detection. J Chromatogr A 1996; 744:167-76. [PMID: 8843665 DOI: 10.1016/0021-9673(96)00173-2] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Over 90% of the lethal cases of mushroom toxin poisoning in man are caused by a species of amanita. The amatoxins (especially alpha- and beta-amanitin) found in amanita deserve special attention, because of their high pharmacological potency, their high natural concentration and their high chemical and thermal stability. Measures can be taken to improve the survival rates (aggressive gastroenteric decontamination, liver protection therapy) if the poisoning is diagnosed correctly and as early as possible. The standard assay for alpha-amanitin is a radioimmunoassay (RIA). Among other reagents, this assay uses 125I-labelled alpha-amaintin, which has a low shelf life. The assay is therefore not available at all hospitals and all year round. In this paper, a first attempt to employ capillary zone electrophoresis (CZE) to quantify amatoxins alpha- and beta-amanitin in urine samples of afflicted patients and in toadstool extracts is described. Diode array detection is used for identification of the resolved substances in the electropherogram. An analysis requires 20 min. The detection limit is 1 microgram/ml, i.e., 5 pg absolute. Relative standard deviations are between 1 and 2% for the calibration standards (peak height and area) and ca. 7.5% for the real samples. Advantages of the CZE over the RIA include lower cost, the possibility of quantifying several toxins in one analysis, less consumption of potentially harmful reagents (no radio-labelled substances, no addition of alpha-amanitin as reagent) and, most importantly, all-year-round availability of the assay. The detection limit is still somewhat high and does not cover the entire clinically relevant range. Attempts to lower the detection limit by the necessary order of magnitude are currently under way in our laboratory. These include application of laser-induced fluorescence detection, liquid chromatography-CZE and CZE-mass spectrometry techniques.
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Brüggemann O, Freitag R. Determination of polycyclic aromatic hydrocarbons in soil samples by micellar electrokinetic capillary chromatography with photodiode-array detection. J Chromatogr A 1995. [DOI: 10.1016/0021-9673(95)00536-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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72
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Sziele D, Brüggemann O, Döring M, Freitag R, Schügerl K. Adaptation of a microdrop injector to sampling in capillary electrophoresis. J Chromatogr A 1994. [DOI: 10.1016/0021-9673(94)80356-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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