Latest ArticlesA copper-catalyzed three-component reaction involving cyclic carbonates, elemental sulfur, and H-phosphonates is presented. It proceeds with excellent yields and provides an attractive approach for the construction of valuable trisubstituted allenyl phosphorothioates using a one-step strategy. Moreover, this method can be easily adapted to large-scale preparation.
Efficient yield of 1O2 determines the photocatalytic degradation rate of antibiotics, but the regulatory mechanism for 1O2 selective generation in O2 activation is still lacking exploration. Herein, oxygen vacancy (OV) modification strategy of MIL-125 was successfully practiced to promote the selective generation of 1O2. Multiple characterizations including extended X-ray absorption fine structure (EXAFS) and electron paramagnetic resonance spectra (EPR) confirmed the formation of oxygen vacancy in OV-MIL-125. The synthesized OV-MIL-125 exhibited greatly enhanced 1O2 selective (~90%) and antibiotics removal rate in water with high mineralization rate. Dynamics analysis of excitons by transient-steady state fluorescence and phosphorescence, transient absorption spectra (TAS) revealed that oxygen vacancy greatly enhanced the intersystem crossing (ISC) of singlet exciton, promoting triplet exciton generation. Density functional theoretical (DFT) calculation also proved the reduced gap of intersystem (ΔEST) and the modulated highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) population which was conducive to intersystem crossing process. Calculation of transition state further confirmed the lower energy barrier for π* orbital spin flip of O2 adsorbed on OV-MIL-125. The Dexter energy transfer involving triplet annihilation dominated the O2 activation mechanism to generate 1O2 instead of the charge transfer to generate O2•− which happened in MIL-125. This study provides new thinking for photocatalytic activation of molecular oxygen and is expected to guide the design of MOF-based catalysts for water treatment.
Spinel oxides, with the formula AB2O4 (A and B represent metal ions) perform superior electrocatalytic characteristic when A and B are transition metals like Co, Fe, Mn, etc. Abundant researches have been attached to the structure designments while methods are often energy-intensive and inefficient. Here, we devised a universal strategy to achieve rapid synthesis of nanocrystalline spinel materials with multiple components (Co3O4, Mn3O4, CoMn2O4 and CoFe2O4 are as examples), where phase formation is within 15 s. Under the Joule-heating shock, a crack-break process of microcosmic phase transformation is observed by in-situ transmission electron microscopy. The half-wave potential values of Co3O4—JH, Mn3O4—JH, CoMn2O4—JH and CoFe2O4—JH in the electrocatalytic oxygen reduction reaction were 0.77, 0.78, 0.79 and 0.76, respectively. This suggests that the Joule heating is a fast and efficient method for the preparation of spinel oxide electrocatalysts.
Metal batteries have attracted considerable attention from researchers because of their low reduction voltage and high specific capacity. However, the reduction in the capacity and lifespan of batteries caused by the dendrite growth of metal anode limits the development of metal batteries. Metal-organic frameworks (MOFs) can be used to protect metal anodes owing to their advantages of ideal specific surface area, tunable porosity, and physiochemical stability in electrolytes. Therefore, MOFs have been extensively investigated in metal batteries. The introduction of MOFs to the metal anode interface can greatly improve the performance of batteries. In this review, the synthesis methods of typical MOFs and their derivatives, their protective mechanism on the metal anode, including Li, Na, K, Zn, and Mg, and their effects on the performance of metal batteries were elucidated. This review would help to design and apply MOFs to the anode interface in metal batteries.
Nanozymes are the paradigm for bridging inorganic nanomaterials with biology and environment for taking the spontaneous responsibilities to outplay natural enzymes. Metal-organic frameworks (MOFs) are mesoporous materials of inorganic-organic coordination, bearing ampoules of active/target sites and having the tendency to mimic natural enzymes. Thus MOF-based nanozymes (NZs) could be recognized for their tremendous potential for bio-catalysis. However, MOFs are of four types namely: modified MOFs, pristine MOFs, MOF-derived materials and MOFs comprised of natural enzymes. The MOFs-based NZ modulated via ultrasound, light, and heat revealed diversified applications. This article is concentrated on different methods for the preparation of MOF-based NZ for mimicking the responses of catalases, multi-functional enzymes, oxidases, superoxide dismutase, hydrolases, and peroxidases, progress and challenges of MOFs/MOF-based materials for exploiting their recent and futuristic approaches in biomedical sector.
Rare earth ions (RE3+)-doped double perovskites have attracted tremendous attention for its fascinating optical properties. Nevertheless, RE3+ generally exhibits poor photoluminescence quantum yield (PLQY) for their parity-forbidden 4f-4f transition and the low doping concentration. Herein, we reported Sb3+/Sm3+-codoped rare earth-based double perovskite Cs2NaLuCl6 that enables efficient visible and near-infrared (NIR) emission, which stems from self-trapped exciton (STE) and Sm3+, respectively. Benefit from up to 72.89% energy transfer efficiency from STE to Sm3+ and high doping concentrations due to similar ionic activity between Sm3+ and Lu3+, thus eruptive PLQY of 74.58% in the visible light region and 23.12% in the NIR light region can be obtained. Moreover, Sb3+/Sm3+-codoped Cs2NaLuCl6 exhibits tunable emission characteristic in the visible light region under different excitation wavelengths, which can change from blue emission (254 nm excitation) to white emission (365 nm excitation). More particularly, only the NIR emission can be captured by the NIR camera when a 700 nm cutoff filter is added. The excellent stability and unique optical properties of Sb3+/Sm3+-codoped Cs2NaLuCl6 enable us to demonstrate its applications in NIR light-emitting diode, triple-mode fluorescence anti-counterfeiting and information encryption. These findings provide new inspiration for the application of rare earth-based double perovskite in optoelectronic devices.
Enhancing the active tumor targeting ability and decreasing the clearance of reticuloendothelial system (RES) are important issues for drug delivery systems (DDSs) in cancer therapy. In recent years, cell membrane camouflage, as one of the biomimetic modification strategies, has shown huge potential. Many natural properties of source cells can be inherited, allowing the DDSs to successfully avoid phagocytosis by macrophages, prolong circulation time, and achieve homologous targeting to lesion tissue. In this study, a cancer cell membrane camouflaged nanoplatform based on gelatin with a typical core-shell structure was developed for cancer chemotherapy. Doxorubicin (DOX) loaded gelatin nanogel (NG@DOX) acted as the inner core, and 4T1 (mouse breast carcinoma cell) membrane was set as the outer shell (M-NG@DOX). The M-NG platform enhanced the ability of homologous targeting due to the surface protein of cell membrane being completely retained, which could promote the cell uptake of homotypic cells, avoid phagocytosis by RAW264.7 macrophages, and therefore increase accumulation in tumor tissue. Meanwhile, due to the better controlled drug release capability of M-NG@DOX, premature release of DOX in circulation could be reduced, minimizing side effects in common chemotherapy. As a result, the biomimetic nanoplatform in this study, obtained by a cancer cell membrane camouflaged drug delivery system, efficiently reached desirable tumor elimination, providing a significant strategy for effective targeted therapy and specific carcinoma therapy.
Epoxy resin-reinforced graphite composites have found extensive application as bipolar plates in fuel cells for stationary power supplies, valued for their lightweight nature and exceptional durability. To enhance the interfacial properties between graphite and epoxy resin (EP), surface oxidation of graphite was carried out using diverse functional groups. Experimental assessments illustrated that the composites with graphite oxide resulted in heightened mechanical strength and toughness compared to pristine graphite, which could be attributed to the excellent interface connection. Moreover, these composites displayed remarkable conductivity while simultaneously retaining their mechanical attributes. Furthermore, molecular dynamics simulations outcomes unveiled that the inclusion of oxygen-containing functional groups on the graphite surface augmented the interfacial energy with EP, and the interface morphology between graphite and resin exhibited heightened stability throughout the stretching process. This simple and effective technique presents opportunities for improving composites interfaces, enabling high load transfer efficiency, and opens up a potential path for developing strong and tough composite bipolar plates for fuel cells.
Melanoma treatment has been revolutionized with the development of targeted therapies and immunotherapies, which shows a positive influence on the patients. However, the long-term efficaciousness of such therapy is restricted by side effects, limited clinical effects as well as quick resistance to treatment. In this work, we prepared magnetocaloric carrier-free bimetallic hydrogels, named manganese-iron oxide nanocubes@polyethylene glycol-hydrogels (MFO@PEG-Gels), to realize ion-interferential cell cycle arrest for melanoma treatment. In detail, the tumor site was exposed to alternating magnetic field (AMF) after intratumorally injected MFO@PEG-Gels, which generated hyperthermia and promoted the sol-gel phase transition for MFO sustained release. Under the tumor microenvironment, hydrogen peroxide triggered MFO degradation to induce Mn2+ and Fe3+ release. On one hand, Mn2+ blocked G1/S phase through the activation of p27 pathway. On the other hand, Fe3+ could arrest the G2/M phase by upregulating the polo-like kinase 4 (PLK4) expression as well as inhibiting autolysosome formation to achieve the enhanced cell cycle arrest, thereby promoting the apoptosis of melanoma cells. In summary, this study proposed ion-interferential cell cycle arrest strategy by a multifunctional and injectable magnetic bimetallic hydrogel for melanoma treatment, which provided a secure and sustainable regimen for enhancing anti-tumor efficacy.
Adenosine triphosphate (ATP), known as a common metabolic product in organism, is not only importance to provide energy in various cellular activities but also is widely explored in the bio-inspired synthetic supramolecular area which becomes a fascinating topic with the rapid development of biology, chemistry and materials science. In this review, the recent advances about ATP interacted with functional small organic compounds and metal coordinated complexes are summarized. The design principles, its function as an active supramolecular matrix, the associated non-covalent binding modes and assembly induced properties including the optical properties, morphologies are presented in details. Besides, their applications for metal ion detecting, enzyme activity monitoring and drug delivery are described due to their excellently dynamic assembly properties, adjustability, and response to stimuli. Finally, an overview of the existing challenges and future prospects of ATP-induced supramolecular systems are also discussed.