Latest ArticlesThe misuse of antibiotics and oxygen-lacking in aquaculture causes serious water environmental problems. Herein, a piezoelectic odd-layered MoS2 is prepared and applied to piezo-catalytic remove tinidazole (TNZ) and other antibiotic pollutants with aeration as a piezo-driving force. About 89.6% of TNZ can be degraded by MoS2 under aeration in the presence of dissolved oxygen with a reaction rate constant of 0.15 min−1, which is 2.4 times higher than that under N2 atmosphere and quiescence conditions. Quenching experiments and electron paramagnetic resonance (EPR) tests identify that singlet oxygen (1O2) and superoxide radical (O2•−) are dominant reactive oxygen species in MoS2/aeration system. These results demonstrate that MoS2 can trigger a piezoelectric effect and produce charge carriers to generate reactive oxygen species with dissolved oxygen (DO) for contaminant degradation with the turbulence and water bubbles rupture driven by aeration.
In this study, two novel spherical/hollow metal-organic frameworks were successfully synthesized, and further modified by a mild non-covalent modification strategy with dopamine and 1, 4-benzenedithiol (BDT) as polymeric monomers to obtain pBDT@PDA-Ni-MOF and pBDT@PDA-Ni/Co-MOF, respectively. The results showed that the above MOFs possessed extremely fast adsorption rates and ideal adsorption capacities for sulfonamides (SAs) and the modified MOFs exhibited enhanced adsorption capacities for SAs owing to a large number of additional functional groups. Then, benefit of their regular morphology and size, a facile syringe-assisted dispersive solid phase extraction (S-DSPE) method was developed for efficient detection of SAs, which will provide a powerful tool for monitoring trace level of SAs in aqueous environment.
Hydrogenation reactions play crucial roles on chemical synthesis and pollutant elimination. The improvement of the ability to activate reactants and increase of the contact probability between the catalysts and reactants are positive to improve the catalytic performance. Herein, we have reported the design of two-dimensional porous Ni-Ni3N-NiMoN heterojunction sheets (2D Mo-Ni based nanosheets) for efficient catalytic hydrogenation of the aromatic nitro-compounds. The heterojunction interfaces provide plentiful active sites to improve the activating ability of the catalyst on the reactants. Additionally, the 2D porous structure facilitates not only the contact of catalytic sites with reactants but also mass transfer and diffusion, both of which are favorable to accelerating the hydrogenation process. As a result, the optimized sample of 2D Mo-Ni sheet exhibits good activity for the hydrogenation of aromatic nitro-compounds by converting 0.2 mmol/L (30 mL) of p-nitrophenol to p-aminophenol within 45 s with good recyclability. The activation energy and the reaction rate at 25 ℃ is 31.11 kJ/mol and 0.0796 s-1, respectively, both of which surpass most of reported non-noble metal catalysts and rivals with most noble metal-based catalysts. The combination of late and early transition metals provides an innovative way to obtain outstanding catalysts for the hydrogenation.
Fluorescence-guided surgery calls for development of near-infrared fluorophores. Despite the wide-spread application and a safe clinical record of Indocyanine Green (ICG), its maximal absorption wavelength at 780 nm is rather short and longer-wavelength dyes are desired to exploit such benefits as low photo-toxicity and deep penetration depth. Here, we report ECY, a stable deep near-infrared (NIR) fluorochromic scaffold absorbing/emitting at 836/871 nm with a fluorescence quantum yield of 16% in CH2Cl2. ECY was further rationally engineered for biological distribution specificity. Analogous bearing different numbers of sulfonate group or a polyethylene glycol chain were synthesized. By screening this focused library upon intravenous injection to BALB/c mice, ECYS2 was identified to be a suitable candidate for bioimaging of organs involved in hepatobiliary excretion, and ECYPEG was found to be a superior candidate for vasculature imaging. They have potentials in intraoperative imaging.
The cancer cells realize their proliferation and metastasis activities based on the special redox adaptation to increased reactive oxygen species (ROS) level, which inversely makes them sensitive to external interference with their redox state. In view of this, in recent decades, researchers have made great efforts to construct a series of novel nanoplatform-based ROS-mediated cancer therapies through increasing ROS generation and inhibiting the ROS elimination. Besides, the multidrug resistance and thermoresistance of tumor are closely related to tumor redox state. Recently, numerous works have shown that ROS regulation in cancer cells can intervene in the expression, function and stability of related proteins to achieve reversal of tumor resistance. In this review, the recent researches about ROS-regulating nanoagents on cancer therapy and tumor resistance alleviation have been well summarized. Finally, the challenges and research directions of ROS-regulating nanoagents for future clinical translation are also discussed.
A simple, practical and eco-friendly visible light-induced alkylation of N-sulfonyl ketamine under metal-, additive-, external photocatalyst-free conditions was developed. This photocatalytic method utilized low cost and abundant alkanes as the atom economy alkyl sources with H2O2 as the environmentally beneficial oxidant, allowing for the efficient construction of diverse valuable 4-alkylated sulfonyl ketamines. The N-sulfonyl ketamine played a dual role of reactant and photocatalyst, thus simplifying the reaction system.
Furocoumarins are an important class of heterocyclic compounds with a fused tricyclic structure of coumarin and furan rings. They are commonly found in bioactive natural products and have a diverse range of biological and pharmaceutical properties, including cytotoxicity, photosensitivity, insecticidal, antibacterial, and antifungal activity, among others. The elegant linear/angular tricyclic skeleton and superior pharmacological properties, make them ideal for building and developing advanced biological scaffolds for biomedical applications. As a result, the family of furocoumarins has been the focus of intensive research, and lots of encouraging progress have been achieved in recent years. This review summarizes the most recent methods reported for the synthesis of the furocoumarin derivative family, along with their applications in medicinal chemistry covering from 2018 to 2022.
Single-atom nanozymes (SANs) have attracted extensive attention due to their characteristics of both single-atom catalysts (SACs) and enzymes. Using spin-polarized density functional theory (DFT) calculations combined with the hybrid solvation model, this work designed a series of carbon-supported Group Ⅷ transition metals TMS4-C SANs, similar to the TMS4 active center of formate dehydrogenase (FADH), aiming to develop highly efficient SANs for CO2 electroreduction. DFT calculations show that compared with TMN4-C, TMS4-C have FADH-like feature, which can selectively reduce CO2 to formic acid. Particularly, CoS4-C is the most promising SAN for CO2 reduction, with a low limiting potential of -0.07 V, which exceeds most reported catalysts. Two descriptors of TMX4-C (X = N, S) based on intrinsic and electronic structure properties were proposed to shed light on the origin activity of candidates. The findings presented here will provide new insights into the design of novel enzyme-like catalysts for electrochemical CO2 reduction.
To understand the deformation mechanism of molecular crystals under mechanical forces will accelerate the molecular design and preparation of deformable crystals. Herein, the relationship between structural halogenation and molecular-level stacking, micro/nanoscale surface morphology, and macroscopic mechanical properties are investigated. Elastic crystals of halo-pyrimidinyl carbazoles (CzM-Cl, CzM-Br and CzM-Ⅰ) with lamellar structure and brittle crystal (CzM-F) were quantitatively analyzed by crystal energy framework (CEF) providing the inter/intralayer interaction energy (Inter/Intra-IE). It is revealed that the elastic crystals bend under external force as a result from stronger Intra-IE to prevent cleavage and weaker Inter-IE for the short-range movement of molecules on the slip plane. This research will provide an insight for the molecular design of flexible crystals and facilitate the development of next-generation smart crystal materials.
The unique structural features represented by micro-nanoneedle tip structure reflect wonderful physical and chemical properties. The tip effect includes the concentration of energy such as electrons, photons and magnetism in the tip region, which has promising applications in the fields of energy conversion, water capture, environmental restoration and so on. In this review, a comprehensive and systematic summary of the latest advances in the application of the tip effect in different fields is provided. Utilizing advanced Finite Difference Time Domain simulation, we further propose our understanding of the fundamental mechanism of the tip effect induced by micro-nanostructure. However, we need to forge the present study to further reveal the essential law of the tip effect from the perspective of theoretical calculations. This review would provide a solid foundation for further development and application of the tip effect.