Latest ArticlesStrand displacement reaction is a crucial component in the assembly of diverse DNA-based nanodevices, with the toehold-mediated strand displacement reaction representing the prevailing strategy. However, the single-stranded Watson-Crick sticky region that serves as the trigger for strand displacement can also cause leakage reactions by introducing crosstalk in complex DNA circuits. Here, we proposed the toeless and reversible DNA strand displacement reaction based on the Hoogsteen-bond triplex, which is compatible with most of the existing DNA circuits. We demonstrated that our proposed reaction can occur at pH 5 and can be reversed at pH 9. We also observed an approximately linear relationship between the degree of reaction and pH within the range of pH 5–6, providing the potential for precise regulation of the reaction. Meanwhile, by altering the sequence orientation, we have demonstrated that our proposed reaction can be initiated or regulated through the same toeless mechanism without the requirement for protonation in low pH conditions. Based on the proposed reaction principle, we further constructed a variety of DNA nanodevices, including two types of DNA logic gates that rely on pH 5/pH 9 changes for initiating and reversing: the AND gate and the OR gate. We also successfully constructed a DNA Walker based on our proposed reaction modes, which can move along a given track after the introduction of a programmable DNA sequence and complete a cycle after 4 steps. Our findings suggest that this innovative approach will have broad utility in the development of DNA circuits, molecular sensors, and other complex biological systems.
Thirty-one new 10,12-disubstituted aloperine derivatives were subtly constructed through a selective oxidation on the 10-α-C–H induced by sulfonyl and a nucleophilic substitution with the stereoselectivity and scalability. Of them, compound 6b displayed a moderate anti-human coronavirus OC43 (HCoV-OC43) potency and blocked the viral entry stage through a host mechanism of action. Using chemoproteomic techniques, both transmembrane serine protease 2 (TMPRSS2) and scavenger receptor class B type 1 (SR-B1) proteins, which act as host cofactors of viral entry, were identified to be the direct targets of 6b against HCoV-OC43. Furthermore, 6b may deactivate the TMPRSS2 by inducing a change in protein conformation, rather than binding to its catalytic center, thus suppressing the viral membrane fusion. Accordingly, our study provided key scientific data for the development of aloperine derivatives into a new class of antiviral candidates against human β-coronavirus, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
High-performance carbon dots (CDs) allowing the application in high-end display devices are highly desirable and usually limited by the absence of simple and easy synthesis methods. In this work, we exploited an easy-to-implement strategy for the one-step synthesis of green-emitting CDs (G-CDs) with superb optical properties. The G-CDs were synthesized using m-phenylenediamine (m-PD) as a single precursor, and the reaction reacted at 180 ℃ for 12 h The resultant G-CDs exhibit high-purity and excitation-independent green fluorescence with the photoluminescence (PL) peak located at 516 nm, full width at half maximum (FWHM) of 46 nm, and PL quantum yield (QY) of ~80% under the 470 nm excitation light. The G-CDs and corresponding composite film prepared with polyvinyl butyral (G-CDs@PVB) exhibit good PL stability after undergoing long-time storage for one year and 360 h exposure under 460 nm blue light. The G-CDs@PVB film was used as color-conversion materials in green-emitting light-emitting diode (LED) application, exhibiting a Commission internationale de l'Eclairage (CIE) chromaticity coordinate of (0.21, 0.44). The film was also used in CD-based liquid crystal display (CD-LCD) application, achieving a color gamut value of 85%. This work will offer a working basis for the synthesis of high-performance CDs as well as their application in displays.
Electrocatalytic nitrogen reduction reaction (NRR) is considered as an attractive approach for ammonia synthesis under mild conditions. A bottleneck of NRR is the exploration of efficient catalysts for accelerating reaction kinetics, among which heterogeneous structures possessing distinct atomic arrangement could modify electronic structure, and therefore altering their NRR activity. Here, we report a facile strategy for fabricating hetero-phase metal oxides derived from metal organic framework that are further integrated with Au nanoparticles as NRR catalysts. The phase composition of zirconia can be easily adjusted by simply changing the reaction temperature, where the monoclinic and tetragonal phases with the roughly close proportions have a distinct interface, leading to a strong interaction between Au and ZrO2. The enhanced interaction renders Au to be more electropositive and facilitates stronger binding to N2. As a result, a remarkable ammonia yield of 22.32 µg h−1 mgcat.−1 and a Faradaic efficiency of 31.92% can be achieved at low overpotential. This work is expected to pave the way for the design of heterogeneous structures and the exploration of hetero-phase nanostructures in boosting the electrocatalytic NRR.
O3-type layered oxide cathodes have been widely investigated due to their high reversible capacities and sufficient Na+ reservoirs. However, such materials usually suffer from complex multistep phase transitions along with drastic volume changes, leading to the unsatisfied cycle performance. Herein, we report a Mg/Ti co-doped O3-type NaNi0.5Mn0.5O2, which can effectively suppress the complex multistep phase transition and realize a solid-solution reaction within a wide voltage range. It is confirmed that, the Mg/Ti co-doping is beneficial to enhance the structural stability and integrity by absorbing micro-strain and distortions. Thus, the as obtained sample delivers an outstanding cyclic performance (82.3% after 200 cycles at 1 C) in the voltage range of 2.0–4.0 V, and a high discharge capacity of 86.6 mAh/g after 100 cycles within the wide voltage range (2.0–4.5 V), which outperform the existing literatures. This co-doping strategy offers new insights into high performance O3-type cathode for sodium ion batteries.
Sulfurized polyacrylonitrile (SPAN) is proposed as a promising cathode material for lithium sulfur batteries. However, the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical performance. In this study, an electrolyte with dual-additives comprising 2-fluoropyridine (2-FP) and lithium difluorobis (oxalato) phosphate (LiDFBOP) was used to improve the performance of Li||SPAN cells. 2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte, leading to its prior reduction. A LiF-rich film can be formed on the electrode, effectively improving the stability of the electrolyte-electrode interfaces and prolonging the life. Simultaneously, LiDFBOP could form an electrolyte-electrode interface film containing a large amount of LixPOyFz species, compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode interface. Hence, an electrode-interface film with good chemical stability and high Li+ transport was established by LiF and LixPOyFz-rich species. The Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5% after 200 cycles at 1.0 C, 25 ℃, comparing to 56.2% capacity retention without additives. Moreover, the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C, comparing to only 813.5 mAh/g using electrolyte without additives. Our results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.
AIEgens can serve as an effective platform for the construction of photosensitizer-based immunogenic cell death (ICD) inducers. To date, several mitochondria or endoplasmic reticulum (ER)-targeted aggregation-induced emission (AIE) molecules have been developed and have evoked massive ICD in cells. However, due to the complex physicochemical environment in cells, these small AIE molecules cannot maintain a stable aggregate state, which not only affects the fluorescence intensity of the photosensitizer but also decreases the generation of reactive oxygen species (ROS), and thus reducing the effect of the photosensitizer to elicit ICD. AIEgen-based nanomicelles, which maintain a stable micellar structure, can prevent defects of AIE molecules in photodynamic therapy (PDT) applications. Therefore, in this study, a mitochondria-targeted AIE nanophotosensitizer was synthesized and used as a highly potent ICD inducer for vaccine preparation and tumor prevention.
The relationship mechanism between the material pore structures and cathodic iodine chemistry plays a vital role in efficient Zn-I2 batteries, but is unclear, retarding further advances. This work innovatively indicates a great contribution of ~2.5 nm pore structure of nanocarbons to efficient iodine adsorption, rapid I− ↔ I2 conversion, and polyiodide inhibition, via scrupulously designing catalysts with controllable pore sizes systematically. The I2-loading within the designed nitrogen-doped nanocarbons can reach up to as high as 60.8 wt%. The batteries based on the cathode deliver impressive performances with a large capacity of 178.8 mAh/g and long-term cycling stability more than 4000 h at 5.0 C. Notably, these is no polyiodide such as I3− and I5− detected during the charge-discharge processes from comprehensive electrochemical cyclic voltammetry, X-ray photoelectron spectroscopy, and Raman technique. This work provides a novel knowledge-guided concept for rational pore design, promising better Zn-I2 batteries, which is also hoped to benefit other advanced energy technologies, such as Li–S, Li-ion, and Al–I2 batteries.
The development of highly efficient catalysts in the cathodes of rechargeable Li-O2 batteries is a considerable challenge. To enhance the electrochemical performance of the Li-O2 battery, it is essential to choose a suitable catalyst material. Copper selenide (CuSe) is considered as a more promising cathode catalyst material for Li-O2 battery due to its better conductivity and rich electrochemical active sites. However, its electrochemical reaction and fundamental catalytic mechanism remain unclear till now. Herein, in-situ environmental transmission electron microscopy technique was used to study the catalysis mechanism of the CuSe nanosheets in Li-O2 batteries during discharge and charge processes. It is found that Li2O was formed and decomposed around the ultrafine-grained Cu during the discharge and charge processes, respectively, demonstrating excellent cycling. This indicate that the freshly formed ultrafine-grained Cu in the conversion reaction catalyzed the latter four-electron-transfer oxygen reduction reaction, leading to the formation of Li2O. Our study provides important understanding of the electrochemistry of the Li-O2 nanobatteries, which will aid the development of high-performance Li-O2 batteries for energy storage applications.
Catalytic enantioselective alkenylation is an efficient method to construct chiral alkene molecules, but the asymmetric alkenylation of simple alkenes catalyzed by metal-free catalysts remains an elusive challenge. Herein, we reported an asymmetric alkenylation of benzoxazinones with diarylethylenes by utilizing a B(C6F5)3/chiral phosphoric acid catalyst. A broad of benzoxazinones and diarylethylenes with electron-withdrawing and electron-donating groups were tolerated (up to 95% yield and 97.5:2.5 e.r.) in the methodology under mild reaction conditions. Moreover, the synthetic utility was confirmed by the scaled-up reaction and transformations of the products. The mechanism was preliminarily explored by control reactions, nonlinear effect experiment and DFT calculations.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
