Latest ArticlesThe enantioselective separation of racemate, particularly those containing C(sp3)-H bonds knowns for their high bond dissociation energies and significant polarity, presents a significant challenge in pharmaceutical synthesis. Recent advances have witnessed the fusion of photocatalysis with hydrogen atom transfer (HAT) methodologies, marking a notable trend in synthesis of chiral molecules. This technique uses the excitation of a catalyst to activate substrates, enabling the selective isomerization of chiral centers containing C(sp3) configurations. This process distinctively facilitates the direct activation of the C(sp3)-H bond in targeted reagents. This review systematically discusses the photocatalytic isomerization of various chiral molecule featuring C(sp3)-H centers, capable of undergoing deracemization through two primary HAT mechanisms: direct and indirect pathways. From the perspective of synthetic organic chemistry, this field has progressed towards the development of isomerization strategies for molecules that incorporate an activating group at the α-position adjacent to the C(sp3) chiral center. Moreover, it covers methodologies applicable to molecules characterized by specific C-C and C-S bond configurations. The integration of photocatalysis with HAT technology thus provides valuable strategies for the synthesis of enantiopure compounds with enhanced selectivity and efficiency.
Chirality, ubiquitous in living matter, plays vital roles in a series of physiological processes. The clarification of the multiple functions of chirality in bioapplications may provide innovative methodologies for engineering anti-tumor agents. Nevertheless, the related research has been rarely explored. In this study, the chiral supramolecular l/d-cysteine (Cys)-Zn2+-indocyanine green (ICG) nanoparticles were constructed through the coordination interaction between l/d-Cys and Zn2+, followed by the encapsulation of ICG. Experimental findings revealed that the d-Cys-Zn2+-ICG exhibited 17.31 times higher binding affinity toward phospholipid-composed liposomes compared to l-Cys-Zn2+-ICG. Furthermore, driven by chirality-specific interaction, a 2.07 folds greater cellular internalization of d-Cys-Zn2+-ICG than l-Cys-Zn2+-ICG was demonstrated. Additionally, the triple-level chirality-dependent photothermal, photodynamic and Zn2+ releasing anti-tumor effects of l/d Cys-Zn2+-ICG in vitro were verified. As a result, the d-formed nanoparticles achieved 1.93 times higher anti-tumor efficiency than the l-formed ones. The triple-level chirality-mediated anti-tumor effect highlighted in this study underscores the enormous potential of chirality in biomedicine and holds substantial significance in improving cancer therapeutic efficacy.
A sp2 carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(VI) removal. The morphology and structure of rBDATN-HCl were analyzed and identified by SEM, FTIR, XRD and solid-state 13C NMR. It is found that the active functional groups, such as hydroxyl and amide, were introduced into BDATN after radiation reduction and acidification. The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(VI) above 99% after 60 min of illumination with a solid-liquid ratio of 0.5 mg/mL, showing outstanding performance, which is attributed to the increase of dispersibility and adsorption sites of rBDATN-HCl. In comparison to the cBDATN-HCl synthesized with chemical reduction, rBDATN-HCl exhibits a better photoreduction performance for Cr(VI), demonstrating the advantages of radiation preparation of rBDATN-HCl. It is expected that more functionalized sp2 carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.
Ferroptosis in combination with immune therapy emerges as a promising approach for cancer therapy. Herein, dual-responsive metal-polyphenol coordinated nanomedicines were developed for pH/glutathione (GSH)-responsive synergistic ferroptosis and immunotherapy. Our innovative strategy involves the development of a manganese-polyphenol coordinated nanostructure, leveraging the biocompatibility of bovine serum albumin (BSA) as a template to encapsulate the anticancer drug sorafenib. The tumor microenvironment (pH/GSH) prompts the disassembly of MnO2 and epigallocatechin gallate (EGCG), thereby releases the anticancer payload. Concurrently, MnO2 acts to deplete intracellular GSH, which in turn suppresses glutathione peroxidase activity, leading to an accumulation of lipid peroxides with cell ferroptosis. Additionally, the release of Mn2+ ions bolster the cyclic guanosine monophosphlic acid (GMP)-adenosine monophosphlic acid (AMP) synthase-stimulator of interferon gene (cGAS-STING) pathway, which, in conjunction with the immunogenic cell death (ICD) effect induced by tumor cell apoptosis, significantly promotes dendritic cell (DC) maturation and enhances the presentation of tumor antigens. This successively ignites a robust innate and adaptive immune response. Both in vitro and in vivo experiments have demonstrated that the concurrent administration of ferroptosis-inducing and immune-stimulating therapies can significantly inhibit tumor growth.
To get large dissymmetric factor (glum) of organic circularly polarized luminescence (CPL) materials is still a great challenge. Although helical chirality and planar chirality are usual efficient access to enhancement of CPL, they are not combined together to boost CPL. Here, a new tetraphenylethylene (TPE) tetracycle acid helicate bearing both helical chirality and planar chirality was designed and synthesized. Uniquely, synergy of the helical chirality and planar chirality was used to boost CPL signals both in solution and in helical self-assemblies. In the presence of octadecylamine, the TPE helicate could form helical nanofibers that emitted strong CPL signals with an absolute glum value up to 0.237. Exceptionally, followed by addition of para-phenylenediamine, the glum value was successively increased to 0.387 due to formation of bigger helical nanofibers. Compared with that of TPE helicate itself, the CPL signal of the self-assemblies was not only magnified by 104-fold but also inversed, which was very rare result for CPL-active materials. Surprisingly, the interaction of TPE helicate with xylylenediamine even gave a gel, which was transformed into suspension by shaking. Unexpectedly, the suspension showed 40-fold stronger CPL signals than the gel with signal direction inversion each other. Using synergy of the helical chirality and planar chirality to significantly boost CPL intensity provides a new strategy in preparation of organic CPL materials having very large glum value.
On-demand droplet manipulation plays a critical role in microfluidics, bio/chemical detection and micro-reactions. Acoustic droplet manipulation has emerged as a promising technique due to its non-contact nature, biocompatibility and precision, circumventing the complexities associated with other methods requiring surface or droplet pretreatment. Despite their promise, existing methods for acoustic droplet manipulation often involve complex hardware setups and difficulty for controlling individual droplet amidst multiple ones. Here we fabricate simple yet effective acoustic tweezers for in-surface and out-of-surface droplet manipulation. It is found that droplets can be transported on the superhydrophobic surfaces when the acoustic radiation force surpasses the friction force. Using a two-axis acoustic tweezer, droplets can be maneuvered along arbitrarily programmed paths on the surfaces. By introducing multiple labyrinthine structures on the superhydrophobic surface, individual droplet manipulation is realized by constraining the unselected droplets in the labyrinthine structures. In addition, a three-axis acoustic tweezer is developed for manipulating droplets in three-dimensional space. Potential applications of the acoustic tweezers for micro-reaction, bio-assay and chemical analysis are also demonstrated.
Singlet oxygen (1O2), as an electrophilic oxidant, is essential for the selective water decontamination of pollutants from water. Herein, we showcase a high-performing electrocatalytic filtration system composed of carbon nanotubes functionalized with CoFe alloy nanoparticles (CoFeCNT) to selectively facilitate the electrochemical activation of O2 to 1O2. Benefiting from the prominently featured bimetal active sites of CoFeCNT, nearly complete production of 1O2 is achieved by the electrocatalytic activation of O2. Additionally, the proposed system exhibits a consistent pollutant removal efficiency > 90% in a flow-through reactor over 48 h of continuous operation without a noticeable decline in performance, highlighting the dependable stability of the system for practical applications. The flow-through configuration demonstrates a striking 8-fold enhancement in tetracycline oxidation compared to a conventional batch reactor. This work provides a molecular level understanding of the oxygen reduction reaction, showing promising potential for the selective removal of emerging organic contaminants from water.
As a novel two-dimensional (2D) material, MXenes are anticipated to have a significant impact on future aqueous energy storage and conversion technologies owing to their unique intrinsic laminar structure and exceptional physicochemical properties. Nevertheless, the fabrication and utilization of functional MXene-based devices face formidable challenges due to their susceptibility to oxidative degradation in aqueous solutions. This review begins with an outline of various preparation techniques for MXenes and their implications for structure and surface chemistry. Subsequently, the controversial oxidation mechanisms are discussed, followed by a summary of currently employed oxidation characterization techniques. Additionally, the factors influencing MXene oxidation are then introduced, encompassing chemical composition (types of M, X elements, layer numbers, terminations, and defects) as well as environment (atmosphere, temperature, light, potential, solution pH, free water and O2 content). The review then shifts its focus to strategies aiming to prevent or delay MXene oxidation, thereby expanding the applicability of MXenes in complex environments. Finally, the challenges and prospects within this rapidly-growing research field are presented to promote further advancements of MXenes in aqueous storage systems.
The intrinsic clustering behavior and kinetically sluggish conversion process of lithium polysulfides seriously limit the electrochemical reversibility of sulfur redox reactions in lithium-sulfur (Li-S) batteries. Here, we introduce molybdenum pentachloride (MoCl5) into the electrolyte which could coordinate with lithium polysulfides and inhibit their intrinsic clustering behavior, subsequently serving as an improved mediator with the bi-functional catalytic effect for Li2S deposition and activation. Moreover, the coordination bonding and accelerated conversion reaction can also greatly suppress the dissolution and shuttling of polysulfides. Consequently, such polysulfide complexes enable the Li-S coin cell to exhibit good long-term cycling stability with a capacity decay of 0.078% per cycle after 400 cycles at 2 C, and excellent rate performance with a discharge capacity of 589 mAh/g at 4 C. An area capacity of 3.94 mAh/cm2 is also achieved with a high sulfur loading of 4.5 mg/cm2 at 0.2 C. Even at -20 ℃, the modified cell maintains standard discharge plateaus with low overpotential, delivering a high capacity of 741 mAh/g at 0.2 C after 80 cycles. The low-cost and convenient MoCl5 additive opens a new avenue for the effective regulation of polysulfides and significant enhancement in sulfur redox conversion.
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
