Protein-Mimetic, Molecularly Imprinted Nanoparticles for Selective Binding of Bile Salt Derivatives in Water

A tripropargylammonium surfactant with a methacrylate-terminated hydrophobic tail was combined with a bile salt derivative, divinyl benzene (DVB), and a photo-cross-linker above its critical micelle concentration (CMC). Surface-cross-linking with a diazide, surface-functionalization with an azido sugar derivative, and free-radical-core-cross-linking under UV irradiation yielded molecularly imprinted nanoparticles (MINPs) with template-specific binding pockets. The MINPs resemble protein receptors in size, complete water-solubility, and tailored binding sites in their hydrophobic cores. Strong and selective binding of bile salt derivatives was obtained, depending on the cross-linking density of the system

Interfacial Molecular Imprinting in Nanoparticle-Stabilized Emulsions

A new interfacial nano and molecular imprinting approach is developed to prepare spherical molecularly imprinted polymers with well-controlled hierarchical structures. This method is based on Pickering emulsion polymerization using template-modified colloidal particles. The interfacial imprinting is carried out in particle-stabilized oil-in-water emulsions, where the molecular template is presented on the surface of silica nanoparticles during the polymerization of the monomer phase. After polymerization, the template-modified silica nanoparticles are removed from the new spherical particles to leave tiny indentations decorated with molecularly imprinted sites. The imprinted microspheres prepared using the new interfacial nano and molecular imprinting have very interesting features: a well-controlled hierarchical structure composed of large pores decorated with easily accessible molecular binding sites, group selectivity toward a series of chemicals having a common structural moiety (epitopes), and a hydrophilic surface that enables the MIPs to be used under aqueous conditions

Electrochemically synthesized polymers in molecular imprinting for chemical sensing

This critical review describes a class of polymers prepared by electrochemical polymerization that employs the concept of molecular imprinting for chemical sensing. The principal focus is on both conducting and nonconducting polymers prepared by electropolymerization of electroactive functional monomers, such as pristine and derivatized pyrrole, aminophenylboronic acid, thiophene, porphyrin, aniline, phenylenediamine, phenol, and thiophenol. A critical evaluation of the literature on electrosynthesized molecularly imprinted polymers (MIPs) applied as recognition elements of chemical sensors is presented. The aim of this review is to highlight recent achievements in analytical applications of these MIPs, including present strategies of determination of different analytes as well as identification and solutions for problems encountered

Caractérisation électrique d'une structure passive en hyperfréquence par mesures et modélisation de lignes CPW

L'étude présentée a pour objectif la détermination des propriétés électriques d'un échantillon par la caractérisation de lignes de transmissions coplanaires (CPW) de dimensions et de nature différentes. La structure étudiée est une structure Métal Isolant Semiconducteur (MIS) pour laquelle la partie isolante est constituée de 2 diélectriques déposés sur un substrat silicium. Des mesures en paramètres S jusqu'à 41GHz par analyseur de réseau vectoriel (VNA) ont permis la détermination des constantes de propagations de chaque ligne CPW par la méthode multilignes. Un phénomène d'ondes lentes (slow wave mode) significatif a été constaté et expliqué. Une modélisation analytique a été conduite, rendant compte du phénomène et corroborant les résultats de mesure. Comparativement, l'utilisation du simulateur électromagnétique (EM) Momentum d'Agilent a permis d'extraire un modèle équivalent de substrat. Finalement, une bonne concordance entre résultats de mesure et modélisation a été constatée

Scalable Modeling of Transient Self-Heating of GaN High-Electron-Mobility Transistors Based on Experimental Measurements

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Large-signal modeling up to W-band of AlGaN/GaN based high-electron-mobility transistors

International audienceThis paper reports on the development of a thermo-electrical non-linear model for sub-100 nm gate length AR:aN/GaN High-Electron-Mobility Transistors (HEMT) grown on silicon (111) substrate by Molecular Beam Epitaxy (MBE). The presented model benefits from the innovative implementations of a sub-network taking into account access resistances frequency dispersion and a double intrinsic current source well suited for DC/RF dispersion losses. A comparison between simulation and experimental results under large-signal operating conditions at both 40 GEls and 94 C,Hz demonstrates the functionality of the implemented model