Ionic liquids monolithic columns for protein separation in capillary electrochromatography.

A series of ionic liquids (ILs) monolithic capillary columns based on 1-vinyl-3-octylimidazolium (ViOcIm(+)) were prepared by two approaches ("one-pot" approach and "anion-exchange" approach). The effects of different anions (bromide, Br(-); tetrafluoroborate, BF4(-); hexafluorophosphate, PF6(-); and bis-trifluoromethanesulfonylimide, NTf2(-)) on chromatography performance of all the resulting columns were investigated systematically under capillary electrochromatography (CEC) mode. The results indicated that all these columns could generate a stable reversed electroosmotic flow (EOF) over a wide pH range from 2.

Molecularly imprinted quartz crystal microbalance sensor based on poly(o-aminothiophenol) membrane and Au nanoparticles for ractopamine determination.

A molecularly imprinted quartz crystal microbalance (QCM) sensor for ractopamine (RAC) detection was developed by electrodepositing a poly-o-aminothiophenol membrane on an Au electrode surface modified by self-assembled Au nanoparticles (AuNPs). The modified electrodes were characterized by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy. This molecularly imprinted QCM sensor showed good frequency response in RAC binding measurements and the introduction of AuNPs demonstrated performance improvements.

An electrochemical sensor for rapid determination of ractopamine based on a molecularly imprinted electrosynthesized o-aminothiophenol film.

A simple electrochemical sensor based on a molecularly imprinted polymer film as the recognition element was developed for ractopamine (RAC) detection. This is the first report of a RAC-imprinted film on a gold electrode surface, synthesized through an electrochemical method using o-aminothiophenol as the functional monomer. The imprinting mechanism and experimental parameters affecting the capability of the imprinted film are discussed here.

A novel ionic liquid monolithic column and its separation properties in capillary electrochromatography.

A novel ionic liquid (IL) monolithic capillary column was successfully prepared by thermal free radical copolymerization of IL (1-vinyl-3-octylimidazolium chloride, ViOcIm(+)Cl(-)) together with lauryl methacrylate (LMA) as the binary functional monomers and ethylene dimethacrylate (EDMA) as the cross-linker in binary porogen. The proportion of monomers, porogens and cross-linker in the polymerization mixture was optimized in detail. The resulting IL-monolithic column could not only generate a stable reversed electroosmotic flow (EOF) in a wide pH range (2.

Novel amperometric sensor using metolcarb-imprinted film as the recognition element on a gold electrode and its application.

A molecularly imprinted film is electrochemically synthesized on a gold electrode using cyclic voltammetry to electropolymerize o-aminothiophenol in the presence of metolcarb (MTMC). The mechanism of the imprinting process and a number of factors affecting the activity of the imprinted film are discussed and optimized. Scanning electron microscope observations and binding measurements have proved that an MTMC-imprinted film (with a thickness of nearly 100 nm) was formed on the surface of the gold electrode.