Ionic-liquid-assisted desorption of DNA from polyamidoamine-grafted silica nanoparticles surface by a low-salt solution.

We studied the influences of imidazolium-based ionic liquids as additives in low ionic strength phosphate solution on releasing DNA from polyamidoamine dendrimer-grafted silica nanoparticle surfaces. The effects of the side-chain length of the imidazolium group, the anion and the concentration of the ionic liquid, the generation of the dendrimer, and the pH and the concentration of the release solution were investigated. It was found that addition of 4 mM 1-hexyl-3-methylimidazolium bromide to 5 mM phosphate at pH 11 could markedly promote the desorption of DNA fragments, with a desorption efficiency of 99.

Polyamidoamine-grafted silica nanoparticles as pseudostationary phases for capillary electrochromatographic separation of proteins.

Polyamidoamine-grafted silica nanoparticles were synthesized, characterized and investigated for the feasibility as pseudostationary phases in alkaline buffer for separation of cationic and anionic proteins, viz., lysozyme, cytochrome C, gamma globulin, and myoglobin. Neither bare silica nanoparticles nor polyamidoamines nor their mixtures as pseudostationary phases could lead to simultaneous separation of the four proteins.

Sensitive and selective capillary electrophoretic analysis of proteins by zirconia nanoparticle-enhanced copper (II)-catalyzed luminol-hydrogen peroxide chemiluminescence.

We report herein a sensitive, selective, convenient CE determination of heme proteins in complex matrices by a sodium-dodecyl-sulfate-assisted, zirconia nanoparticle-enhanced copper (II)-catalyzed luminol-hydrogen peroxide chemiluminescence (CCLHPCL). Introducing a segment of sodium dodecyl sulfate to the capillary after sample injection not only rendered selective detection by quenching the luminescence signals from the non-heme proteins but also owning to the suppressed protein adsorption, led to significant improvement in separation efficiency and detection sensitivity. The signals were further improved by addition of ZrO(2) nanoparticles to the chemiluminescence solution.