Search results for "imprint"
showing 10 items of 194 documents
Hierarchical Imprinting Using Crude Solid Phase Peptide Synthesis Products as Templates
2003
The crude products resulting from solid-phase peptide synthesis can be used as epitope templates to generate surface-confined sites for the template and larger peptides containing the template motif. This offers a facile route to robust affinity stationary phases for the chromatographic separation of peptides.
Binding characteristics of molecularly imprinted polymers based on fungicides in hydroalcoholic media
2015
An iprodione-imprinted polymer was prepared by copolymerization of methacrylamide and ethylene glycol dimethacrylate using a noncovalent imprinting approach. Methacrylamide was chosen using molecular dynamics simulations. To concentrate iprodione from hydro-alcoholic solutions, batch sorption of iprodione on the imprinted polymer were conducted. The equilibrium time for iprodione sorption is 20 min, and the corresponding kinetic mechanism follows the pseudo-second order indicating a strong interaction between iprodione and the imprinted polymer. Langmuir, Freundlich, and Dubinin-Radushkevich models were used to fit the isotherm of iprodione sorption. The imprinted polymer was found to be mo…
Affinity Distributions of a Molecularly Imprinted Polymer Calculated Numerically by the Expectation-Maximization Method
2003
Affinity distributions are calculated from adsorption isotherm data obtained for the enantiomers of L- and D-phenylalanine anilide (PA) on native and thermally annealed polymers molecularly imprinted with L-PA. The calculation is obtained with an iterative algorithm called expectation-maximization that does not require prior fit of the data to an isotherm model before inversion and thus yields a distribution indicative of the data only. The results show bimodal distributions, suggestive of a two-site model describing relatively selective and nonselective adsorption modes of the L-enantiomer and a corresponding unimodal/nonselective adsorption mode for the D-enantiomer. The nonselective adso…
Molecularly imprinted composite materials via iniferter-modified supports
2002
Wide pore silica (DP = 100 nm) and gel-type or macroporous (12% nominal crosslinking density) Merrifield resins were modified with iniferter groups for grafting of crosslinked molecularly imprinted or non-imprinted polymer layers through quasi-living polymerisation. Prior to iniferter coupling, the silica supports were premodified by silanisation with p-(chloromethyl)phenyl trimethoxysilane. The iniferter groups were then introduced by reacting the resin-bound chloromethyl groups with sodium N,N-diethyldithiocarbamate. It was shown that the coupling yield, measured as the conversion of the chloromethyl groups, could be varied between 5 and 85% through kinetic control, with the fastest conve…
Enzyme-modified electrodes for biosensors and biofuel cells
2019
In biosensors and biofuel cells, it is often desirable to accelerate the electron transfer rate between the enzyme and electrode surface to improve the performance of the devices (sensitivity or power output). To this end, in this review, we focus on three important strategies available to improve the performance of enzyme-modified electrodes: the use of protein engineering, designer polymers, and the introduction of nanomaterials. Engineering the protein or proteins that constitute the biocatalytic elements allow tuning their stability, activity, and specificity. It can also allow changing the enzyme immobilization efficiency (adsorption vs. covalent immobilization, for example). If direct…
Distribution of molecularly imprinted polymer layers on macroporous silica gel particles by STEM and EDX
2005
Abstract Using transmission electron microscopy (TEM) in parallel and scanning mode (STEM) combined with energy dispersive X-ray spectroscopy (EDX) the distribution of molecularly imprinted polymer layers covalently grafted on the inner and outer surface of macroporous silica gel particles was observed. The grafting was achieved using a special initiator system ( iniferter ) and applied on a well known model system producing molecularly imprinted layers with l -phenyl alanine analide ( l -PA) as template. By staining the sample with RuO 4 before its embedment in epoxy resin and cutting ultra thin slices it was possible to identify the stained grafted polymer on the silica matrix by EDX. Bas…
Towards Plastic Electronics: Patterning Semiconducting Polymers by Nanoimprint Lithography
2002
The direct patterning of functional semiconducting polymers (see Figure) has been achieved with a nanoimprint lithography technique. The room‐temperature process described is time‐saving as repeated temperature cycling is not required. In addition, due to the direct patterning approach the need for further processing steps (plasma treatment) to pattern the underlying semiconducting material is eliminated.
Soluble Single-Molecule Nanogels of Controlled Structure as a Matrix for Efficient Artificial Enzymes
2006
Experimental design approach in the synthesis of molecularly imprinted polymers specific for iprodione fungicide
2015
International audience; An experimental design (ED) approach was applied to study the weight of three factors in the synthesis of a molecularly imprinted polymer (MIP) specific for iprodione fungicide. The objective was to obtain a high specific polymer with the best performance of iprodione binding. Thirteen iprodione-imprinted polymers and 13 non-imprinted polymers (NIP) were synthesized according to ED having 3 influencing factors: the polymerization method, the crosslinker nature and the functional monomer type. For each factor, two levels were studied: bulk and precipitation polymerization for the first factor, trimethylolpropane trimethacrylate (TRIM) and ethylene glycol dimethacrylat…