JPC – Journal of Planar Chromatography – Modern TLC - High-performance thin-layer chromatography, which is a quick qualitative and quantitative method, was used to determine 3 kinds of... 相似文献
In this work, a convenient and dual-signal readout optical sensing platform for the sensitively and selectively determination of beta-glucosidase (β-Glu) activity was reported using protein-inorganic hybrid nanoflowers [BSA-Cu3(PO4)2·3H2O] possessing peroxidase-mimicking activity. The nanoflowers (NFs) were facilely synthesized through a self-assembled synthesis strategy at room temperature. The as-prepared NFs could catalytically convert the colorless and non-fluorescent Amplex Red into colored and highly fluorescent resorufin in the presence of hydrogen peroxide via electron transfer process. β-Glu could hydrolyze cyanogenic glycoside, using amygdalin (Amy) as a model, into cyanide ions (CN?), which can subsequently efficiently suppress the catalytic activity of NFs, accompanied with the fluorescence decrease and the color fading. The concentration of CN? was controlled by β-Glu-triggered enzymatic reaction of Amy. Thus, a sensing system was established for fluorescent and visual determination of β-Glu activity. Under the optimum conditions, the present fluorescent and visual bimodal sensing platform exhibited good sensitivity for β-Glu activity assay with a detection limit of 0.33 U·L?1. The sensing platform was further applied to determinate β-Glu in real samples and satisfactory results were attained. Additionally, the optical sensing system can potentially be a promising candidate for β-Glu inhibitors screening.
The rational design of advanced nanohybrids (NHs) with optimized interface electronic environment and rapid reaction kinetics is pivotal to electrocatalytic schedule. Herein, we developed a multiple heterogeneous Co9S8/Co3S4/Cu2S nanoparticle in which Co3S4 germinates between Co9S8 and Cu2S. Using high-angle annular-dark-field imaging and theoretical calculation, it was found that the integration of Co9S8 and Cu2S tends to trigger the interface phase transition of Co9S8, leading to Co3S4 interlayer due to the low formation energy of Co3S4/Cu2S (−7.61 eV) than Co9S8/Cu2S (−5.86 eV). Such phase transition not only lowers the energy barrier of oxygen evolution reaction (OER, from 0.335 eV to 0.297 eV), but also increases charge carrier density (from 7.76×1014 to 2.09×1015 cm−3), and creates more active sites. Compared to Co9S8 and Cu2S, the Co9S8/Co3S4/Cu2S NHs also demonstrate notable photothermal effect that can heat the catalyst locally, offset the endothermic enthalpy change of OER, and promote carrier migrate, reaction intermediates adsorption/deprotonation to improve reaction kinetics. Profiting from these favorable factors, the Co9S8/Co3S4/Cu2S catalyst only requires an OER overpotential of 181 mV and overall water splitting cell voltage of 1.43 V to driven 10 mA cm−2 under the irradiation of near-infrared light, outperforming those without light irradiation and many reported Co-based catalysts. 相似文献
Cellulose - Dye contamination of water supplies has a serious threat to human health, prompting the development of highly effective and eco-friendly adsorbents. In this work, polyelectrolyte... 相似文献
Herein, we demonstrate that a very familiar, yet underutilized, physical parameter—gas pressure—can serve as signal readout for highly sensitive bioanalysis. Integration of a catalyzed gas‐generation reaction with a molecular recognition component leads to significant pressure changes, which can be measured with high sensitivity using a low‐cost and portable pressure meter. This new signaling strategy opens up a new way for simple, portable, yet highly sensitive biomedical analysis in a variety of settings. 相似文献
The gelation behavior of lithocholate (LC?) with different metal ions in water was investigated. The microstructures of hydrogels were determined to be three‐dimensional (3D) networks of fibrous aggregates. The formation of fibrils was speculated to be mainly driven by the coordination between carboxylate of LC? and metal ions, accompanied by the assistance of noncovalent interactions such as electrostatic and hydrophobic interactions. The hydrogels, which can maintain the mechanical strength at higher temperature, exhibit thermal stability. Their gelation capability was enhanced with the increase in acidity. The hydrogels of LC? and Cu2+ mixtures served as the precursors for producing network nanostructures of CuS nanoparticles. These new CuS networks exhibit high fluorescence quenching ability and can act as an effective fluorescent sensing platform for ssDNA detection. 相似文献
A Ru‐catalyzed direct C? H activation/meta‐bromination of arenes bearing pyridyl, pyrimidyl, and pyrazolyl directing groups has been developed. A series of bromo aryl pyridines and pyrimidines have been synthesized, and further coupling reactions have also been demonstrated for a number of representative functionalized arenes. Preliminary mechanistic studies have revealed that this reaction may proceed through radical‐mediated bromination when NBS is utilized as the bromine source. This type of transformation has opened up a new direction for the radical non‐ipso functionalization of metal with regard to future C? H activation development that would allow the remote functionalization of aromatic systems. 相似文献