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Synchronized “Click” and Templated Synthesis of a Fluorescent Pyrene Crown Ether
摘要： The reaction of 6,8-bisethynylpyrene-2-carboxylic acid methyl ester with 1-azido-2-(2-(2-azidoethoxy)ethoxy)ethoxy)ethane using standard “click” chemistry produced a 1+1 crown ether (CPYR). The copper ions used both catalyse the reaction and provide a template for ensuring smooth cyclisation. The X-ray crystal structure of the compound reveals the two triazole groups are non-coplanar with the pyrene moiety. The triazole groups are more co-planar with the pyrene subunit in the first-excited singlet state as revealed by a density functional theory (DFT) calculated molecular structure (B3LYP, 6-311G). Partially structured emission observed in acetonitrile is consistent with the calculation result. In acetonitrile solution the macrocycle CPYR interacts with a Na+ ion to form a complex in which the ion binds with the crown and the pyrene residue.
关键词： pyrene,structure,click,binding,crown ether
更新于2025-11-19 16:46:39
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Facile fabrication of cross-linked fluorescent organic nanoparticles with aggregation-induced emission characteristic via the thiol-ene click reaction and their potential for biological imaging
摘要： Over the past several years, the biomedical applications of fluorescent organic nanoparticles (FONs) with aggregation-induced emission (AIE) feature have been extensively explored because the AIE-active FONs could effectively overcome the aggregation caused quenching (ACQ) effect of FONs based on conventional organic dyes. The development of novel methods for synthesis of AIE-active FONs plays a centre role for their biomedical applications. In this work, we reported a facile one-step thiol-ene click reaction for fabrication of AIE-active FONs through conjugation of acrylated PEG and AIE-active tetraphenylethylene (TPE) with two ene bonds using pentaerythritol tetra(3-mercaptopropionate) as the linkage. The successful synthesis of TPE containing AIE-active copolymers was evidenced by various characterization techniques. The particle size and fluorescence properties of the resultant TPE-S-PEG copolymers were evaluated by transmission electronic microscopy and fluorescence spectroscopy. Moreover, the cell viability and cell uptake behavior was also examined to evaluate their potential for biological imaging. We demonstrated that the cross-linked TPE-S-PEG show small size, high water dispersibility, low cytotoxicity and strong fluorescence for tracing. All of these advantages endow the TPE-S-PEG FONs great potential for biological imaging applications. Furthermore, this novel click reaction can take place under mild experimental conditions with high efficiency. It could be also further expanded for preparation of multifunctional AIE-active materials due to the universality of the thiol-ene click reaction and good precursor applicapability. Taken together, we have developed a novel and effective thiol-ene click reaction to fabricate the cross-linked AIE-active FONs, which display excellent physicochemical and biological properties and are promising for biomedical applications.
关键词： thiol-ene click reaction,Aggregation-induced emission,biomedical applications,fluorescent organic nanoparticles,cross-linked FONs
更新于2025-09-23 15:23:52
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Polysiloxane-based Hyperbranched Fluorescent Materials Prepared by Thiol-ene “Click” Chemistry as Potential Cellular Imaging Polymers
摘要： Hyperbranched polymers have attracted increasing interest due to their unique properties which possess excellent RI and thermal stability, and have been widely used in fields of drug delivery, catalysts, liquid crystal and so on. Herein, polysiloxane-based hyperbranched fluorescent materials (P1 and P2) were synthesized by thiol-ene “click” chemistry. Then, novel polysiloxane-based hyperbranched fluorescent materials (P1-Ln3+) has been prepared by rare earth ions coordination. In view of the splendid fluorescence characteristics and favorable stability of P1-Ln3+, it has been applied in biological imaging. P1-Ln3+ has gained commendable applications in bioimaging.
关键词： Fluorescence materials,Living cells imaging,Hyperbranched polymers,Thiol-ene "click" chemistry,Coordination,Rare earth ions
更新于2025-09-23 15:23:52
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Photodynamic Antimicrobial Cellulosic Material Through Covalent Linkage of Protoporphyrin IX onto Lyocell Fibers
摘要： Here, we report the preparation of porphyrin-functionalized Lyocell fibers according to an azide-alkyne click concept. First, azido-modified Lyocell fibers and alkynylated protoporphyrin building blocks were prepared through alkoxysilane chemistry and Steglich esterification, respectively. Lyocell fibers were pre-activated by swelling in organic solvents in order to increase the accessibility of hydroxyl groups in the subsequent silanization process. The azide-equipped cellulosic matrix reacted with the propargyl groups of the protoporphyrin IX derivative in a copper-catalyzed azide-alkyne cycloaddition reaction (CuAAC), by which protoporphyrin IX was introduced onto the surface of the Lyocell fibers. The modified building blocks and the final functionalized cellulosic materials were comprehensively characterized by FTIR, NMR, UV/Vis spectroscopy and elemental analysis. Photo-bactericidal activity of modified fibers against 2 gram-positive bacteria strains, including Staphylococcus aureus and Bacillus subtilis, were investigated and compared to those of unmodified and azido-modified Lyocell fibers. The results confirmed the photo-antibacterial activity of the synthesized fibers against both bacteria strains.
关键词： photoactivity,protoporphyrin IX,cellulose fibers,click chemistry,Alkoxysilane
更新于2025-09-23 15:23:52
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The role of dipole structure and their interaction on the electromechanical and actuation performance of homogeneous silicone dielectric elastomers
摘要： Grafting polar groups onto elastomer chains has proven to be an effective method to achieve high performance homogenous dielectric elastomers (DE). Up to now, there still lacks an in-depth understanding of the effect of structure and content of these grafted dipoles on the electromechanical properties of the modified DE. In this study, three kinds of polar groups including carboxyl (COOH), hydroxyl (OH), and ester (COOCH3) are grafted onto Polymethylvinylsiloxane (PMVS) by using a photochemical thiol-ene reaction to prepare PMVS-COOH, PMVS-OH and PMVS-COOCH3 DE. Three grafting degrees (15%, 50% and 95%) were prepared for each kind of modified PMVS. Interestingly, although the dipolar moment of COOH is higher than that of OH and COOCH3, at the same grafting degree, the dielectric constant of PMVS-OH is much higher than that of PMVS-COOCH3 and PMVS-COOH. At high grafting degree (50% and 95%), the actuated strain at a specific electric field of PMVS-OH is significantly higher than that of PMVS-COOH and PMVS-COOCH3. The actuated train at a 15 kV/mm sharply increases from 0.2% for PMVS to 9.1% for PMVS-OH with the grafting degree of 95%, higher than that of the commercial silicone DE and the new structured silicone DE reported previously. These dielectric, mechanical and actuated properties are affected by the combined effects of moment, mobility and interactions of these dipoles, which have been deeply discussed. The present study provides guidance for the preparation of high-performance homogeneous DE by rational designing the dipolar structure and content.
关键词： Polymethylvinylsiloxane,dipoles,electromechanical properties,thiol-ene click chemistry,dielectric elastomers,actuated strain
更新于2025-09-23 15:23:52
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Stable Molecular Surface Modification of Nanostructured, Mesoporous Metal Oxide Photoanodes by Silane and Click Chemistry
摘要： Binding functional molecules to nanostructured mesoporous metal oxide surfaces provides a way to derivatize metal oxide semiconductors for applications in dye-sensitized photoelectrosynthesis cells (DSPECs). The commonly used anchoring groups, phosphonates and carboxylates, are unstable as surface links to oxide surfaces at neutral and high pH, leading to rapid desorption of appended molecules. A synthetically versatile molecular attachment strategy based on initial surface-modification with a silyl azide followed by click chemistry is described here. It has been used for the stable installation of surface-bound metal complexes. The resulting surfaces are highly stabilized toward complex loss with excellent thermal, photochemical, and electrochemical stabilities. The procedure involves binding 3-azidopropyltrimethoxysilane (APTMS) to nanostructured mesoporous TiO2 or tin-doped indium oxide (ITO) electrodes by silane attachment followed by azide-terminated, Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC) reactions with an alkyne-derivatized ruthenium(II) polypyridyl complex. The chromophore-modified electrodes display enhanced photochemical and electrochemical stabilities compared to phosphonate surface binding with extended photoelectrochemical oxidation of hydroquinone for more than ~6 h with no significant decay.
关键词： DSPECs,photostability,stability,silane chemistry,electrostability,Ru(II) polypyridyl complexes,click chemistry,Dye-sensitized,photoanode
更新于2025-09-23 15:22:29
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Enzyme immobilization in completely packaged freestanding SU-8 microfluidic channel by electro click chemistry for compact thermal biosensor
摘要： Enzyme immobilization method in packaged freestanding microfluidic channel is developed for biomolecule assembly of biosensor in this research. A new micro fluidic fabrication method is proposed to fabricate freestanding fluidic structure by MEMS technology. The SU-8 polymer channel is treated by plasma treatment to change hydrophobic surface to hydrophilic property which can automatically drive the liquid into the channel by capillary force. The electro click chemistry method is carried out in hydrophilic SU-8 micro channel by capillary effect. The results show that enzyme immobilization can be immobilized by electro click chemistry in completely packaged freestanding channel. The proposed enzyme immobilization method in micro channel is capable of minimizing biosensor device for healthcare application.
关键词： Capillary effect,SU-8 polymer,Electro click chemistry,Enzyme immobilization,Microfluidic
更新于2025-09-23 15:22:29
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An Enzyme-Free MicroRNA Assay Based-on Fluorescence Counting of Click Chemical Ligation-Illuminated Magnetic Nanoparticles with Total Internal Reflection Fluorescence Microscopy
摘要： MicroRNAs (miRNAs) have been considered as promising cancer biomarkers. However, the simple but sensitive detection of low levels of miRNAs in biological samples still remains challenging. Herein, we wish to report an entirely enzyme-free, simple and highly sensitive miRNA assay based on the counting of cycling click chemical ligation (3CL)-illuminated fluorescent magnetic nanoparticles (MNPs) with a total internal reflection fluorescence microscopy (TIRFM). In this strategy, each miRNA molecule can trigger many cycles of click chemical ligation reactions to produce plentiful ligated oligonucleotides (ODNs) with both 5’-biotin and 3’-fluorophore, resulting in efficient signal amplification. It is worth noting that only the ligated ODNs can bring fluorophores onto streptavidin-functionalized MNPs (STV-MNPs). Notably, merely 10 fluorescent molecules on each 50 nm MNP can make it bright enough to be clearly visualized by the TIRFM, which can significantly improve the detection sensitivity for miRNA. Through fluorescence counting of individual MNPs and integrating their fluorescence intensities, the amount of target miRNA can be quantitatively determined. This miRNA assay can be accomplished in a mix-and-read manner just by simply mixing the enzyme-free 3CL reaction system with the MNPs before TIRFM imaging, which avoids tedious immobilization, washing and purification steps. Despite the extremely simple operation, this strategy exhibits high sensitivity with a quite low detection limit of 50 fM target miRNA as well as high specificity to well discriminate miRNA sequences with a single-base variation. Furthermore, the applicability of this method in real biological samples is also verified through the accurate detection of miRNA target in cancer cells.
关键词： click chemistry,microRNA,TIRFM,magnetic nanoparticle,fluorescence counting
更新于2025-09-23 15:21:21
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Triple Orthogonal Labeling of Glycans Applying Photoclick Chemistry
摘要： Bioorthogonal labeling of multiple biomolecules is of current interest in chemical biology. For the visualization of carbohydrates, metabolic glycoengineering (MGE) has been shown to be an appropriate approach. Here, we report that the nitrile imine–alkene cycloaddition (photoclick reaction) is a suitable ligation reaction in MGE. Using a mannosamine derivative with an acrylamide reporter group, that is efficiently metabolized by cells and that quickly reacts in the photoclick reaction, we achieved the labeling of sialic acids on the surface of living cells. Screening of several alkenes unraveled that a previously reported carbamate-linked methylcyclopropene reporter, that is well suited for the inverse-electron-demand Diels-Alder (DAinv) reaction, has a surprisingly low reactivity in the photoclick reaction. This enabled us to achieve for the first time a triple labeling of glycans by the combination of DAinv, photoclick, and copper-free click chemistry.
关键词： carbohydrates,tetrazines,bioorthogonal reactions,click chemistry,metabolic engineering
更新于2025-09-23 15:21:21
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Controlled Covalent Functionalization of 2H-MoS2 with Molecular or Polymeric Adlayers.
摘要： Most air-stable 2D materials are relatively inert, which makes their chemical modification difficult. In particular, in the case of MoS2, the semiconducting 2H-MoS2 is much less reactive than its metallic counterpart, 1T-MoS2. As a consequence, there are hardly any reliable methods for the covalent modification of 2H-MoS2. An ideal method for the chemical functionalization of such materials should be both mild, not requiring the introduction of a large number of defects, and versatile, allowing for the decoration with as many different functional groups as possible. Herein, a comprehensive study on the covalent functionalization of 2H-MoS2 with maleimides is presented. The use of a base (Et3N) leads to the in situ formation of a succinimide polymer layer, covalently connected to MoS2. In contrast, in the absence of base, functionalization stops at the molecular level. Moreover, the functionalization protocol is mild (occurs at room temperature), fast (nearly complete in 1h), and very flexible (11 different solvents and 10 different maleimides tested). In practical terms, the procedures described here allow for the chemist to manipulate 2H-MoS2 in a very flexible way, decorating it with polymers or molecules, and with a wide range of functional groups for subsequent modification. Conceptually, the spurious formation of an organic polymer might be general to other methods of functionalization of 2D materials, where a large excess of molecular reagents is typically used.
关键词： click chemistry,MoS2,maleimide,2D materials,covalent functionalization
更新于2025-09-23 15:21:01