Latest ArticlesHerein, a simple and effective outer-surface interactions assisted supramolecular hierarchical assembly has been first exploited to uniformly distribute tungstosilicic acid (TSA) inside the porous structure of cucurbit[10]uril-based single-layer 2D supramolecular-organic-frameworks (Q[10]-SOFs) in water. Importantly, the 2D Q[10]-SOFs can further serve as light harvesting antenna, achieving fast energy transfer to the embedded redox-active TSA upon photoexcitation, resulting in efficient visible light-driven selective oxidation of benzyl alcohols into the corresponding aldehydes in high yield at room temperature. Further studies revealed that the integrated of 2D Q[10]-SOFs and TSA played a key role in the catalytic process, due to the presence of a novel stepwise electron transfer route in the single-layer hybrid 2D structures.
The micro-dispersion structure of silica fillers exerts significant influences on the performance characteristics of rubber-based products. How to monitor this parameter is an important issue in the rubber industry, but there is currently no suitable technical solution for numerical monitoring that can be applied in automatic production line. The labeling of silica in rubber is a challenge that bottlenecks the development of numerical quality monitoring technology. In this work, we employed the organometallic europium to modify silica endowing the fluorescence properties for characterization. It provides more feasible solutions for visually studying the relationship between the submicroscopic structure and macroscopic properties of inorganic-filled polymers, and is the key foundation for achieving numerical monitoring of rubber filler qualities in industry.
The rapid emergence of drug-resistant bacterial strains undermines the efficacy of conventional antibiotics, necessitating the development of alternative therapies. Antimicrobial photodynamic therapy (PDT) is a promising approach, but its effectiveness is often limited by the suboptimal photocatalytic activity of photosensitizers. In this study, we introduce a novel photoresponsive carbon-based antibacterial agent, Ce6/g-C3N4, which combines the photocatalytic properties of graphite-phase carbon nitride (g-C3N4) with the photodynamic attributes of chlorin e6 (Ce6). This agent, with an average particle size of 250.7 nm, demonstrates significantly enhanced photocatalytic activity. Additionally, the strong affinity of Ce6/g-C3N4 for bacteria and efficient delivery of Ce6 result in an inhibition rate exceeding 99% against Gram-positive bacteria and excellent biofilm eradication under light irradiation. In vivo experiments reveal that Ce6/g-C3N4 effectively inhibits bacterial growth on wounds, and promotes wound healing post-light treatment, while maintaining good biocompatibility. Overall, the Ce6/g-C3N4 antibacterial agent synergizes photodynamic and photocatalytic mechanisms, offering a new avenue for the photo-mediated, multi-strategic treatment of bacterial infections and wound healing.
Utilizing small molecules as markers for specific cells or organs within biosystems is a crucial approach for studying and regulating physiological processes. However, current tagging strategies, due to the presence of exposed highly reactive groups, suffer from drawbacks such as low tagging efficiency or insufficient spatial specificity, thereby diminishing their expected effectiveness. Consequently, there is a pressing need to develop a strategy capable of in situ labeling of active groups in response to cellular or in vivo stimuli, ensuring both high tagging efficiency and spatial specificity. In this work, we devised a strategy for releasing aldehyde groups activated by hypochlorous acid (HOCl). Compounds synthesized through this strategy can release the fluorophore methylene blue (MB) and aldehyde-based compounds upon HOCl activation. Given high reactivity of the released aldehyde group, it can effectively interact with macromolecules in biological systems, facilitating tagging and enabling prolonged imaging. To validate this concept, we further incorporated a naphthalimide structure with stable light emission to create SW-110. SW-110 can specifically respond to in vitro and endogenous HOCl, when release MB, it also releases naphthalimide fluorophore with highly reactive aldehyde group for tagging within cells. This strategy provides a simple but efficient strategy for proximity tagging in situ.
In most Suzuki–Miyaura carbon-carbon cross-coupling reactions, the borabicyclo[3.3.1]nonane scaffold (9-BBN) only serves as an auxiliary facilitating the transmetalation step and thus is transformed into by-products. There are rare examples where the 9-BBN derivatives serve as the potentially diverse C8 building blocks in cross-coupling reactions. Herein, we report a cobalt-catalyzed migratory carbon-carbon cross-coupling reaction of the in situ formed 9-BBN ate complexes to afford diverse aryl- and alkyl-functionalized cyclooctenes. Preliminary mechanistic studies suggest the oxidation-induced cis-bicyclo[3.3.0]oct-1-ylborane is the key intermediate in this migratory cross-coupling reaction, which promotes the development of other diverse migratory cross-coupling of borate complexes.
A thickness-controllable method for preparing metal-organic framework hollow nanoflowers on magnetic cores (Fe3O4@MOFs HFs) was demonstrated for the first time. The petal of magnetic core with hollow nanoflower structure served as medium for assembling UiO-66-NH2 shell with different thickness. To further improve its performance, Zr4+ was immobilized on the surface of Fe3O4@UiO-66-NH2. Compared with conventional Fe3O4@UiO-66-NH2-Zr4+ nanospheres, the Fe3O4@UiO-66-NH2-Zr4+ HFs showed increased enrichment performance for phosphopeptides. The Fe3O4@UiO-66-NH2-Zr4+ HFs served as an attractive restricted-access adsorption material exhibited good selectivity (mβ-casein:mBSA=1:1000), high sensitivity (1.0 fmol) and excellent size-exclusion effect (mβ-casein digests:mBSA=1:200). Furthermore, the Fe3O4@UiO-66-NH2-Zr4+ HFs was successfully applied to the specific capture of ultratrace phosphopeptide from complex biological samples, revealing the great potential for the identification and analysis of trace phosphopeptides in clinical analysis. This work can be easily extended to the fabrication of diverse mag-MOF HFs with multifunctional and easy to post-modify properties, and open up a new avenue for the design and construction of new MOFs material.
The separation of alicyclic ketones and alicyclic alcohols is one of the challenges in the field of petrochemical industry. However, traditional separation methods suffer from excessive energy consumption, complicated operation, and unsatisfactory separation efficiency for substances with similar boiling points. Herein, we offer an innovative method for the separation of alicyclic ketones and alicyclic alcohols employing nonporous adaptive crystals (NACs) of perethylated pillar[5]arene (EtP5) and perethylated pillar[6]arene (EtP6). NACs of EtP5 cannot adsorb either alicyclic ketones or alicyclic alcohols because of the small cavity size of EtP5. By contrast, NACs of EtP6 can separate cyclopentanone from the vapor mixture of cyclopentanone/cyclopentanol (v:v = 1:1) and cyclohexanone from the vapor mixture of cyclohexanone/cyclohexanol (v:v = 1:1) with purities of 99.1% and 100%, respectively. Density functional theory calculations show that the selectivity comes from the thermodynamic stability of the newly formed crystal structure after adsorption of the preferred guest molecule. Moreover, NACs of EtP6 can be reused without losing selectivity and performance.
MicroRNA-133a (miRNA-133a) and cardiac troponin I (cTnI) are different-type crucial biomarkers of acute myocardial infarction (AMI), whose levels are great significance for AMI diagnosis and treatment. Herein, a novel photoelectrochemical-electrochemical (PEC-EC) dual-mode biosensing platform for dual-target assays of miRNA-133a and cTnI was developed. In which, a PEC-EC dual-mode sensing platform for miRNA-133a was constructed based on the changes of the photocurrent inhibition effect and the electrochemical signal of Fc on the Fc-hairpin DNA probe (Fc-HP)/ZnCdS-quantum dots (QDs)/ITO electrode. Furthermore, under magnetic separation and the specific interaction between cTnI and its aptamer, the N-doped porous carbon-ZnO polyhedra (NPC-ZnO)-hemin-capture DNA probe hybrid (NH-CP) was obtained and introduced to the Fc-HP/ZnCdS-QDs/ITO electrode via hybridization between NH-CP and Fc-HP. The hemin molecules encapsulated in NH-CP could effectively induce the photocurrent-polarity-switching of the Fc-HP/ZnCdS-QDs/ITO electrode and generate a new electrochemical signal originating from hemin. Thus, cTnI was assayed sensitively and selectively by the PEC-EC dual-mode biosensing platform. Here, Fc and hemin not only serve as the electrochemical indicators, but also respectively inhibit the photocurrent and switch the photocurrent polarity of ZnCdS-QDs. Furthermore, the proposed biosensing platform could be easily expanded to the detection of other multiplex-type biomarkers via the change of the sequences of the related DNA probes, implying its significant potential in clinical diagnosis and biological analysis.
Liquid-liquid phase separation (LLPS) of proteins and nucleic acids is a common phenomenon in cells that underlies the formation of membraneless organelles. Although the macroscopic behavior of biomolecular coacervates has been elucidated by microscopy, the detailed dynamic properties of proteins/peptides during the LLPS process remain poorly characterized. Here, site-directed spin labeling-electron paramagnetic resonance (SDSL-EPR) spectroscopy was employed to characterize the dynamic properties of a minimal model LLPS system consisting of positively charged peptides and RNA. The degree of phase separation, indicated by broadening of the EPR spectrum of the spin-labeled peptide due to slow molecular tumbling, was monitored by EPR. In addition, three distinct populations with varying molecular motion during LLPS, featuring different spectral lineshapes, were identified. These populations included a fast motion component (Ⅰ), a slower motion component (Ⅱ) associated with peptides in the dispersed phase and an immobile component (Ⅲ) observed in the dense phase. With gradual titration of the peptides to RNA, the EPR spectrum gradually shifted, reflecting changes in the populations of the components. Together, SDSL-EPR method not only provides new insights into the dynamic behavior of biomolecules during LLPS, but also offers a sensitive method for biomolecular phase separation processes at the molecular level.
An enantioselective catalytic method for the direct [4 + 1] annulation of yne–allylic acetates with pyrazolones has been realized by a copper-catalyzed remote strategy. A variety of enantioenriched spiropyrazolones are rapidly accessed in high yields with moderate to good enantiocontrol. The facile follow-up transformations highlight its potential utility in the synthesis of diverse spiropyrazolones building blocks.