New monolithic materials comprising zeolitic imidazolate framework (ZIF‐8) located on the pore surface of poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) monolith previously functionalized with N‐(3‐aminopropyl)‐imidazole have been prepared via a layer‐by‐layer self‐assembly strategy. These new ZIF‐8@monolith hybrids are used as solid‐phase carriers for enzyme immobilization. Their performance is demonstrated with immobilization of a model proteolytic enzyme trypsin. The best of the conjugates enable very efficient digestion of proteins that can be achieved in mere 43 s.
A new simple, time-saving method of preparing highly dispersed Pt nanoparticles with large electrochemically active area (ECA)
on three-dimensional dendrite-like Au supported on Si (100) was successfully developed by electroless displacement deposition
(EDD). The as-prepared catalysts were characterized by field-emission scanning electron microscope and high-resolution transmission
electron microscopy. The electro-catalytic properties of Pt/Au/Si for methanol and CO electrooxidation were investigated by
cyclic voltammetry, chronoamperometry, and electrochemical impedances spectra. The results show that Pt/Au/Si catalyst prepared
by EDD method presents the higher electro-catalytic activity and higher stability than that of Pt/Si composite. The electro-catalytic
activity of Pt supported on Au could be enhanced with the growth of Au, leading to the higher electro-catalytic properties
toward methanol and CO oxidation. The anodic peak of CO of Pt/Au/Si catalyst showed negatively shifted with respect to similarly
prepared Pt/Si electrode. The supposed schematic of the reaction was also introduced. Overall, the approach provides a convenient
method to prepare the Pt catalyst on Au dendrites with high ECA properties for DMFC and PEMFC through bottom-up assembly. 相似文献
A molecular dithiane-based approach to synthesis of novel photolabile phospholipids is developed. These lipids are used in formulations with egg-POPC and cholesterol to prepare light-sensitive liposomes. Irradiation of such liposomes in PBS buffer (medium pressure mercury lamp, Pyrex filter, lambda > 300 nm) significantly increases the bilayer permeability and accelerates the release of entrapped small organic molecules by an order of magnitude. A simple assay, based on (1)H or (19)F PFG NMR measurements of diffusion coefficients, is developed to monitor light-induced unloading of the probe molecules. 相似文献
Large-area ZnS nanowires were synthesized through a vapor phase deposition method. X-ray diffraction and electron microscopy results show that the products are composed of single crystalline ZnS nanowires with a cubic structure. The nanowires have sharp tips and are distributed uniformly on silicon substrates. The diameter of the bases is in the range of 320-530 nm and that of the tips is around 20-30 nm. The strong ultraviolet emission in the photoluminescence spectra also demonstrates that the ZnS nanowires are of high crystalline perfection. Field emission measurements reveal that the ZnS nanowires have a fairly low threshold field, which may be ascribed to their very sharp tips, rough surfaces and high crystal quality. The perfect field emission ability of the ZnS nanowires makes them a promising candidate for the fabrication of flexible cold cathodes. 相似文献