Owing to the considerable significance of fluoride anions for health and environmental issues, it is of great importance to develop methods that can rapidly, sensitively and selectively detect the fluoride anion in aqueous media and biological samples. Herein, we demonstrate a robust fluorescent turn‐on sensor for detecting the fluoride ion in a totally aqueous solution. In this study, a biocompatible hydrophilic polymer poly(ethylene glycol) (PEG) is incorporated into the sensing system to ensure water solubility and to enhance biocompatibility. tert‐Butyldiphenylsilyl (TBDPS) groups were then covalently introduced onto the fluorescein moiety, which effectively quenched the fluorescence of the sensor. Upon addition of fluoride ion, the selective fluoride‐mediated cleavage of the Si? O bond leads to the recovery of the fluorescein moiety, resulting in a dramatic increase in fluorescence intensity under visible light excitation. The sensor is responsive and highly selective for the fluoride anion over other common anions; it also exhibits a very low detection limit of 19 ppb. In addition, this sensor is operative in some real samples such as running water, urine, and serum and can accurately detect fluoride ions in these samples. The cytotoxicity of the sensor was determined to be Grade I toxicity according to United States Pharmacopoeia and ISO 10993‐5, suggesting the very low cytotoxicity of the sensor. Moreover, it was found that the senor could be readily internalized by both HeLa and L929 cells and the sensor could be utilized to track fluoride level changes inside the cells. 相似文献
Agricultural paper mulch is an indispensable part of modern agriculture. It had the functions of heat preservation, moisture preservation, insect resistance, disease prevention, and weed growth inhibition. In order to extend the service life of the paper mulch, we use the solution immersion method to modify the surface of the paper mulch. A super-hydrophobic paper mulch is mainly prepared by using hydrophobic silica. The static contact angle of the super-hydrophobic paper mulch with water is 160.6°. The super-hydrophobic paper mulch samples were immersed in acid solution (pH?=?4.6 H2SO4) and alkaline solution (pH?=?8.5 NaOH). The main instruments are contact angle tester, tensile testing machine and high-speed camera. The hydrophobic properties, mechanical properties and rebound properties of the two kinds of paper mulches were compared. The results showed that the tensile strength and droplet bounce height of the superhydrophobic paper mulch decreased after being soaked in acid or alkaline solution for 48 h. The mass loss rate of paper mulch was more significant in acid solution, but its contact angle was still greater than 145°, and it had good bounce performance. After observing the microscopic morphology of its surface, it was found that silica had a micro-rough structure on the surface of the paper mulch. The method was simple and environmentally friendly, and can alleviate the problem of poor acid and alkali corrosion resistance of the paper mulch, and had extraordinary significance for environmental protection.
Assisted by graphene oxide(GO),nano-sized LiMn0.6Fe0.4PO4 with excellent electrochemical performance was prepared by a facile hydrothermal method as cathode material for lithium ion battery.SEM and TEM images indicate that the particle size of LiMn0.6Fe0.4PO4(S2)was about 80 nm in diameter.The discharge capacity of LiMn0.6Fe0.4PO4 nanoparticles was 140.3 mAh-g^1 in the first cycle.It showed that graphene oxide was able to restrict the growth of LiMn0.6Fe0.4PO4 and it in situ reduction of GO could improve the electrical conductivity of LiMn0.6Fe0.4PO4 material. 相似文献
Porous tantalum nitride (Ta3N5) single crystals, combining structural coherence and porous microstructure, would substantially improve the photoelectrochemical performance. The structural coherence would reduce the recombination of charge carriers and maintain excellent transport properties while the porous microstructure would not only reduce photon scattering but also facilitate surface reactions. Here, we grow bulk-porous Ta3N5 single crystals on a two-centimeter scale with (002), (023), and (041) facets, respectively, and show significantly enhanced photoelectrochemical performance. We show the preferential facet growth of porous crystals in a lattice reconstruction strategy in relation to lattice match and lattice channel. We present the facet engineering to enhance light absorption, exciton lifetime and transport properties. The porous Ta3N5 single crystal boosts photoelectrochemical oxidation of alcohols with the (002) facet showing the highest performance of >99 % alcohol conversion and >99 % aldehyde/ketone selectivity. 相似文献
The European Physical Journal Special Topics - This paper generalizes a second-order-memristor-based jerk circuit, which is achieved by substituting the first-order memristor contained diode-bridge... 相似文献
Theranostic nanosystems that integrate diagnosis and therapy have garnered increasing attention for personalized medicine.The integration of the versatile nanoparticles to fabricate self-assembled theranostic nanomedicines becomes increasingly important in current medical research.Mesoporous silica nanoparticles(MSN)with their highly attractive physicochemical properties and favorable morphological attributes represent ideal templates for the controlled assembly and integration of functional nanomaterials to fabricate self-assembled theranostic nanomedicines.The rationally designed combination strategy and heterostructure will improve the overall bioavailability and preserve the unique property of each nanocomponent.In this review,the cutting-edge strategies for the designed fabrication of MSN-templated self-assembled nanomedicines are summarized.We categorize MSN-based nanomedicines by their unique heterostructures,including core-shell,yolk-shell,core-satellite,heterodimer and core-shell-satellite structures,and discuss the controlled assembly approaches as well as the intriguing applications for disease theranostics.Finally,a perspective on the challenges in the clinical translation of self-assembled theranostic nanomedicines is highlighted. 相似文献
The radical–radical coupling reaction is an important synthetic strategy. In this study, the iron-catalyzed radical–radical cross-coupling reaction based on the decarboxylation of keto acids and decarbonylation of aliphatic aldehydes to obtain valuable aryl ketones is reported for the first time. Remarkably, when tertiary aldehydes were used as carbonyl sources, ketone esters were selectively obtained instead of ketones. The gram-scale preparation of aryl ketone through this strategy was easily achieved by using only 3 mol % of the iron catalyst. As a proof-of-concept, the bioactive molecule flurprimidol was synthesized in two steps by using this strategy. 相似文献