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Polyamide plays a pivotal role in engineering thermoplastics. Constrained by the harsh conditions and arduous procedures for its industrial synthesis, developing facile synthesis of polyamides is still challengeable and holds profound significance. Herein, we successfully utilized water as one of the monomers to synthesize functional polyamides under ambient conditions. A powerful multicomponent polymerization of water, isocyanides, and chlorooximes was established in phosphate-buffered saline. Soluble and thermally stable polyamides with high weight-average molecular weights (up to 53900) were obtained in excellent yields (up to 95%). The polymerization exhibits unique polymerization-induced emission characteristics, successfully converting non-emissive monomers into unconventional emissive polymers. Notably, the resultant polyamides could undergo effective post-modification via the hydroxyl-yne click reaction. By incorporating various functional groups into the polyamide, its emission color could be fine-tuned from blue to green and to red. Remarkably, the refractive index (n) of the polyamide at 589 nm could be increased from 1.6173 to 1.7227 and the Δn could be unprecedentedly as high as 0.1054 for non-heavy atom-containing polymers after post-modification, and its micron-thick films exhibited excellent transparency in the visible region. Thus, this work not only establishes a powerful polymerization toward novel polyamides but also opens up an avenue for their versatile functionalization.
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Transition-metal-catalyzed C-H activation has greatly benefited the synthesis and development of functional polymer materials, and the construction of multifunctional fused (hetero)cyclic polymers via novel C-H activation-based polyannulations has emerged as a charming but challenging area in recent years. Herein, we report the first cobalt(III)-catalyzed cascade C-H activation/annulation polymerization (CAAP) approach that can efficiently transform readily available aryl thioamides and internal diynes into multifunctional sulfur-containing fused heterocyclic (SFH) polymers. Within merely 3 h, a series of SFH polymers bearing complex and multisubstituted S,N-doped polycyclic units are facilely and efficiently produced with high molecular weights (absolute Mn up to 220400) in excellent yields (up to 99%), which are hard to achieve by traditional methods. The intermediate-terminated SFH polymer can be used as a reactive macromonomer to controllably extend or modify polymer main chains. The structural diversity can be further enriched through facile S-oxidation and N-methylation reactions of the SFH polymers. Benefiting from the unique structures, the obtained polymers exhibit excellent solution processability, high thermal and morphological stability, efficient and readily tunable aggregate-state fluorescence, stimuli-responsive properties, and high and UV-modulatable refractive indices of up to 1.8464 at 632.8 nm. These properties allow the SFH polymers to be potentially applied in diverse fields, including metal ion detection, photodynamic killing of cancer cells, fluorescent photopatterning, and gradient-index optical materials.
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Energy conversion, particularly light to heat conversion, has garnered significant attention owing to its prospect in renewable energy exploitation and utilization. Most previous efforts have focused on developing organic photothermal materials for low-temperature applications, whereas the importance of simplifying the preparation methods of photothermal materials and enhancing their maximum photothermal temperature have been less taken. Herein, we prepare an organic near-infrared (NIR) photothermal material namely ATT by a spontaneous [2+2] cycloaddition-cycloreversion reaction. In addition to the solution-based method, ATT could also be readily preapred by ball milling in a high yield of 90 % in just 15â min. ATT powder exhibits a broad absorption extending beyond 2000â nm, excellent processability, and thermal stability. Remarkably, ATT powder can reach an unprecedently temperature as high as 450 °C while maintaining excellent photostability upon photoirradiation. Leveraging its extraordinary photothermal and processable properties, ATT was used in the high-temperature applications, such as photo-ignition, photo-controlled metal processing and high-temperature shape memory, all of which offer spatiotemporal control capabilities. This work provides a new approach to prepare organic photothermal materials with high temperatures, and pave the way for their applications in extreme environments.
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Nitrile compounds are abundant, stable, cheap, and readily available natural and chemical industrial sources. However, the efficient conversion of nitrile monomers to functional polymers is mostly limited due to their inert reactivity, and developing efficient polymerizations based on nitrile monomers under very mild conditions is still a big challenge. In this work, a facile and powerful base-catalyzed acetonitrile-azide click polymerization was successfully established under ambient conditions. This polymerization also enjoys the merits of short reaction time (15 min), 100% atom economy, transition-metal-free catalyst system, and regioselectivity. A series of poly(5-amino-1,2,3-triazole)s (PATAs) with high weight-average molecular weights (Mw, up to 204,000) were produced in excellent yields (up to 99%). The PATAs containing tetraphenylethene (TPE) moieties exhibit unique aggregation-induced emission (AIE) characteristics, which could be used to sensitively detect Fe(III) ions with a low limit of detection (1.205 × 10-7 M) and to specifically image lysosomes of living cells. Notably, PATAs could be facilely post-modified due to their containing primary amino groups in the polymer chains even through a one-pot tandem reaction. Thus, this work not only establishes a new powerful click polymerization to convert stable nitriles but also generates a series of PATAs with versatile properties for diverse applications.
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Total volatile basic nitrogen (TVB-N) is a vital indicator for assessing seafood freshness and edibility. Rapid on-site detection of volatile basic nitrogen (VBN) is of significant importance for food safety monitoring. In this study, highly luminescent self-assembled copper nanoclusters (Cu NCs@p-MBA), synthesized using p-mercaptobenzoic acid (p-MBA) as the ligand, were utilized for the sensitive detection of VBNs. Under acidic conditions, Cu NCs@p-MBA formed compact and well-organized nanosheets through noncovalent interactions, accompanied by intense orange fluorescence emission (651 nm). The benzene carboxylic acid part of Cu NCs@p-MBA provided the driving force for supramolecular assembly and exhibited a strong affinity for amines, particularly low-molecular-weight amines such as ammonia (NH3) and trimethylamine (TMA). The quantitative determination of NH3 and TMA showed the detection limits as low as 0.33 and 0.81 ppm, respectively. Cu NCs@p-MBA also demonstrated good responsiveness to putrescine and histamine. Through density functional theory (DFT) calculations and molecular dynamics (MD) simulations, the precise atomic structure, assembly structure, luminescent properties, and reaction processes of Cu NCs@p-MBA were studied, revealing the sensing mechanism of Cu NCs@p-MBA for highly sensitive detection of VBNs. Based on the self-assembled Cu NCs@p-MBA nanosheets, portable fluorescent labels were developed for semiquantitative, visual, and real-time monitoring of seafood freshness. Therefore, this study exemplified the high sensitivity of self-assembly induced emission (SAIE)-type Cu NCs@p-MBA for VBNs sensing, offering an efficient solution for on-site monitoring of seafood freshness.
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Cobre , Nitrogênio , Cobre/química , Corantes Fluorescentes/química , Histamina , Alimentos MarinhosRESUMO
Ferroptosis is associated with the occurrence and development of many diseases, which is the result of an imbalance in cellular metabolism and oxidation-reduction balance. Therefore, it is an effective therapeutic strategy that simultaneously regulating the intracellular oxidation-reduction system. Herein, a click reaction of alkynylamide with thiol groups in the presence of amine or in PBS (pH = 7.4) is developed, which can react efficiently with thiol substances, such as cysteine (Cys), glutathione (GSH), and bovine serum albumin (BSA). Notably, MBTB-PA, an aggregation-induced emission (AIE) photosensitizer with an alkynylamide unit, is synthesized and its intracellular behavior is visualized in situ by fluorescence imaging, demonstrating its excellent ability to target the endoplasmic reticulum. Furthermore, MBTB-PA reacted with proteins in tumor cells, consumed reducing substances, and triggered intracellular oxidative stress, resulting in cell death. Based on this reaction therapy strategy, click reaction is combined with photodynamic therapy to achieve effective killing of tumor cells by simultaneously raising the intracellular oxidative state and reducing the reductive state. This work not only develops an application of click reaction of alkynamide with thiol in bioconjugation and anti-tumor therapy, but also provides feasible ideas for organic reactions in the exploration of organisms.
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Química Click , Compostos de Sulfidrila , Compostos de Sulfidrila/química , Humanos , Linhagem Celular Tumoral , Animais , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/farmacologia , Fármacos Fotossensibilizantes/uso terapêuticoRESUMO
Acid-base equilibria play a critical role in biological processes and environmental systems. The development of innovative fluorescent polymeric materials to monitor acid-base equilibria is highly desirable. Herein, a novel catalyst-free click polymerization of aldehyde-activated internal diynes and dithiols was established, and exclusively Markovnikov poly(formyl sulfide)s (PFSs) with high molecular weights and moderate stereoregularity were produced in high yields. Because of the aromatic units and sulfur atoms in their main chains, these polymers possessed high refractive index values. By introducing the fluorene and aldehyde moieties, the resulting PFSs could act as a fluorescent sensor for sensitive hydrazine detection. Taking advantage of the reaction of the aldehyde group and hydrazine, imino-PFSs with remarkable and reversible fluorescence change through alternating fumigation with HCl and NH3 were easily acquired and further applied in multicolor patterning, a rewritable material and quadruple-mode information encryption. Additionally, a test strip of protonated imino-polymer for the tracking of bioamines in situ generated from marine product spoilage was also demonstrated. Collectively, this work not only provides a powerful click polymerization to enrich the multiplicity of sulfur-containing materials, but also opens up enormous opportunities for these functional polysulfides in diverse applications.
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Aggregation-induced emission (AIE) luminogens (AIEgens) are attractive for the construction of non-doped blue organic light-emitting diodes (OLEDs) owning to their high emission efficiency in the film state. However, the large internal inversion rate (kIC (Tn) ) between high-lying triplet levels (Tn ) and Tn-1 causes a huge loss of triplet excitons, resulting in dissatisfied device performance of these AIEgens-based non-doped OLEDs. Herein, we designed and synthesized a blue luminogen of DPDPB-AC by fusing an AIEgen of TPB-AC and a DMPPP, which feature hot exciton and triplet-triplet annihilation (TTA) up-conversion process, respectively. DPDPB-AC successfully inherits the AIE feature and excellent horizontal dipole orientation of TPB-AC. Furthermore, it owes smaller kIC (Tn) than TPB-AC. When DPDPB-AC was applied in OLED as non-doped emitting layer, an outstanding external quantum efficiency of 10.3 % and an exceptional brightness of 69311â cd m-2 were achieved. The transient electroluminescent measurements and steady-state dynamic analysis confirm that both TTA and hot exciton processes contribute to such excellent device performance. This work provides a new insight into the design of efficient organic fluorophores by managing high-lying triplet excitons.
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Light has profoundly impacted modern medicine and healthcare, with numerous luminescent agents and imaging techniques currently being used to assess health and treat diseases. As an emerging concept in luminescence, aggregation-induced emission (AIE) has shown great potential in biological applications due to its advantages in terms of brightness, biocompatibility, photostability, and positive correlation with concentration. This review provides a comprehensive summary of AIE luminogens applied in imaging of biological structure and dynamic physiological processes, disease diagnosis and treatment, and detection and monitoring of specific analytes, followed by representative works. Discussions on critical issues and perspectives on future directions are also included. This review aims to stimulate the interest of researchers from different fields, including chemistry, biology, materials science, medicine, etc., thus promoting the development of AIE in the fields of life and health.
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Corantes Fluorescentes , Substâncias Luminescentes , Corantes Fluorescentes/química , Luminescência , Diagnóstico por Imagem , Atenção à SaúdeRESUMO
The development of functional materials for tumor immunogenicity enhancement is desirable for overcoming the low therapeutic efficiency and easy metastasis during tumor treatments. Herein, the thermoresponsive nanoparticles composed of photothermal agent (PTA) and click reactive reagent are developed for enhanced immunotherapy application. A Ni-bis(dithiolene)-containing PTA with intense near-infrared absorption and efficient photothermal conversion is developed for thermoresponsive nanoparticles construction. The generated heat by encapsulated PTA further induces the phase transition of thermoresponsive nanoparticles with the release of chemotherapy reagent to react with the amino groups on functional proteins, realizing PTT and chemotherapy simultaneously. Moreover, the immunogenic cell death (ICD) of cancer cells evoked by PTT could be further enhanced by the released reactive reagent. As a result, the synergistic effect of photothermal treatment and reaction-mediated chemotherapy can suppress the growth of a primary tumor, and the evoked ICD could further activate the immune response with the suppression of a distant tumor. This synergistic treatment strategy provides a reliable and promising approach for cancer immunotherapy in clinic.
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Nanopartículas , Neoplasias , Animais , Camundongos , Terapia Fototérmica , Fototerapia , Neoplasias/terapia , Antígenos de Neoplasias , Linhagem Celular Tumoral , ImunoterapiaRESUMO
High refractive index polymers (HRIPs) have drawn attention for their optoelectronic applications and HRIPs with excellent transparency and facile preparation are highly demanded. Herein, sulfur-containing all organic HRIPs with refractive indices up to 1.8433 at 589 nm and excellent optical transparency even in one hundred micrometre scale in the visual and RI region as well as high weight-average molecular weights (up to 44500) are prepared by our developed organobase catalyzed polymerization of bromoalkynes and dithiophenols in yields up to 92%. Notably, the fabricated optical transmission waveguides using the resultant HRIP with the highest refractive index display a reduced propagation loss compared with that generated by the commercial material of SU-8. In addition, the tetraphenylethylene containing polymer not only exhibits a reduced propagation loss, but also is used to examine the uniformity and continuity of optical waveguides with naked eyes because of its aggregation-induced emission feature.
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Exploring approaches to utilize abundant water to synthesize functional molecules and polymers with efficient clusteroluminescence properties is highly significant but has yet to be reported. Herein, a chemistry of water and alkyne is developed. The synthesized products are proven as nonaromatic clusteroluminogens that could emit visible light. Their emission colors and luminescent efficiency could be adjusted by manipulating through-space interaction using different starting materials. Besides, the free-standing polymeric films with much high photoluminescence quantum yields (up to 45.7%) are in situ generated via a water-involved interfacial polymerization. The interfacial polymerization-enhanced emission of the polymeric films is observed, where the emission red-shifts and efficiency increases when the polymerization time is prolonged. The synthesized polymeric film is also verified as a Janus film. It exhibits a vapor-triggered reversible mechanical response which could be applied as a smart actuator. Thus, this work develops a method to synthesize clusteroluminogens using water, builds a clear structure-property relationship of clusteroluminogens, and provides a strategy to in situ construct functional water-based polymeric films.
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A ratiometric fluorescent tag based on dual-emissive hydrophobic carbon dots (H-CDs) with well volatile base nitrogens (VBNs)-response was fabricated, offering the in-situ, real-time, and visual evaluation of seafood freshness. The presented H-CDs aggregates exhibited a sensitive response to VBNs, with a limit of detection of 7 µM and 137 ppb for spermine and ammonia hydroxide, respectively. Subsequently, a ratiometric tag was successfully fabricated by depositing dual-emissive CDs on cotton paper. Upon the treatment with ammonia vapour, the presented tag exhibited highly recognizable colour variations from red to blue under UV light. In addition, the cytotoxicity was explored by CCK8 assay, and the results proved the nontoxicity of the presented H-CDs. To our knowledge, this is the first ratiometric tag based on dual-emissive CDs with aggregation-induced emission properties for recognition of VBNs and seafood freshness in a real-time and visual manner.
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Pontos Quânticos , Pontos Quânticos/química , Carbono/química , Amônia , Corantes Fluorescentes/química , Nitrogênio , Alimentos MarinhosRESUMO
Seafood is highly perishable and monitoring its freshness this thus an important issue. For the first time, the current study developed a dual-mode freshness indicator based on d-penicillamine capped bimetallic gold/copper nanoclusters (DPA-Au/CuNCs) as a response probe for simultaneous monitoring of ammonia and temperatures to assess seafood freshness. Results indicated that the prepared DPA-Au/CuNCs have good sensitivity toward ammonia, with a limit of detection of 0.14 ppm. The indicator as a gas sensor for ammonia vapour detection exhibited highly recognizable fluorescence colour changes and the variations from white to yellow were observed with increasing storage temperature under natural light. For confirming its practical applications, the indicator was used to simultaneously monitor ammonia and temperatures during the storage of shrimp and fish, showing good potential for practical applications in evaluating seafood freshness for the food industry.
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Amônia , Alimentos Marinhos , Animais , Peixes , Embalagem de Produtos , Alimentos Marinhos/análise , Temperatura , Cobre/química , Ouro/química , NanoestruturasRESUMO
The development of facile polymerizations toward functional heterocyclic polymers is of great significance for chemistry and materials science. As an important class of heterocyclic polymers, polyoxadiazoles (PODs) have found applications in various fields. However, the synthetic difficulties of PODs greatly restrict their structural diversity and property investigation. Herein, we report a series of catalyst-free multicomponent polymerizations (MCPs) that can facilely synthesize functional PODs with well-defined and diversified topological structures from commercially available or readily accessible aldehydes, carboxylic acids, secondary amines, and (N-isocyanimino)triphenylphosphorane at room temperature. Unlike conventional Ugi polycondensations, the present Ugi-type MCPs can in situ generate oxadiazole moieties in polymer backbones. The obtained PODs possess good solubility, high thermal and morphological stability, and excellent film-forming ability. The introduction of aggregation-induced emission (AIE) moieties together with the inherent structural features of PODs endow these polymers with multiple functionalities. The AIE-active linear PODs can form fluorescent microporous films with stable and ordered structures based on the simple breath figure patterning method, and the self-assembly morphologies can be directly visualized by fluorescence microscopy in a high-contrast and sensitive manner. Moreover, both the linear and hyperbranched AIE-active PODs possess excellent biocompatibility, good lysosome specificity, and excellent photobleaching resistance, which enable them to serve as promising lysosome-specific fluorescent probes in biological imaging.
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A near-infrared (NIR) luminogen TST was designed and used to efficiently trigger HSP90α protein knockdown through photo-thermal conversion based on a gene interference strategy, by which in vitro and in vivo tumor ablation were significantly acquired at low-temperature.
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Hipertermia Induzida , Neoplasias , Humanos , Linhagem Celular Tumoral , Regulação para Baixo , Fototerapia , Terapia Fototérmica , Temperatura , Proteínas de Choque Térmico HSP90/metabolismoRESUMO
The research on pharmacology usually focuses on the structure-activity relationships of drugs, such as antibiotics, to enhance their activity, but often ignores their optical properties. However, investigating the photophysical properties of drugs is of great significance because they could be used to in situ visualize their positions and help us to understand their working metabolism. In this work, we identified a class of commercialized antibiotics, such as levofloxacin, norfloxacin, and moxifloxacin (MXF) hydrochloride, featuring the unique aggregation-induced emission (AIE) characteristics. By taking advantage of their AIE feature, antibiotic metabolism in cells could be in situ visualized, which clearly shows that the luminescent aggregates accumulate in the lysosomes. Moreover, after a structure-activity relationship study, we found an ideal site of MXF to be modified with a triphenylphosphonium and an antibiotic derivative MXF-P was prepared, which is able to specifically differentiate bacterial species after only 10 min of treatment. Moreover, MXF-P shows highly effective broad-spectrum antibacterial activity, excellent therapeutic effects and biosafety for S. aureus-infected wound recovery. Thus, this work not only discovers the multifunctionalities of the antibiotics but also provides a feasible strategy to make the commercialized drugs more powerful.
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It is well-known that bacterial infections will induce a variety of diseases in the clinic. In particular, the emergence of drug-resistant bacteria has increased the threat to human health. The development of multiple modes of therapy will effectively fight against drug-resistant bacterial infections. In this work, we covalently attached an AIE photosensitizer to the antibiotic of moxifloxacin hydrochloride (MXF-HCl) and synthesized an antibiotic derivative, MXF-R, with pharmacological activity and photodynamic activation. In infected cells, MXF-R showed enhanced fluorescence after it specifically binds to bacteria; thus, in situ visualization of the bacteria was realized. Notably, through chemo- and photodynamic therapy, MXF-R exhibited better antibacterial activity than its parent antibiotic in rapid sterilization, and it achieved effective killing for moxifloxacin resistant bacteria. In addition, MXF-R shows a broad-spectrum antibacterial effect and could be used in the recovery therapy of infected wounds in mice, demonstrative of a significant therapeutic effect and good biological safety. Thus, as a promising multifunctional antibacterial agent, MXF-R will have tremendous potential in in situ visualization study and killing of drug-resistant bacteria. This work provides an innovative strategy for solving critical disease through the combination of materials and biomedical sciences.
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Pathogenic bacteria infections, especially multidrug resistant bacteria infections have aroused worldwide attention due to their severe threats to human beings. Thus, the development of highly effective antibacterial reagents is very important. However, the design of antimicrobials is still quite challenging for the lack of a universal design strategy. Here, a synergistic manipulation strategy of dipole-dipole and anion-π+ interaction is proposed for constructing highly efficient antimicrobials with aggregation-induced emission (AIE) feature. Firstly, four anion-π+ -type AIE luminogens were designed and synthesized. Due to the electron-donating and hydrophilic characteristic of methoxy groups, 3MOTPO containing three methoxy groups showed the largest dipole moment (5.06 Debye) and dual anion-π+ interactions in the solid state. Driven by both dipole-dipole and anion-π+ interactions, 3MOTPO showed the strongest bacterial binding ability and the best antibacterial activities (MIC90 =3.76â µM). The work offers a deep insight into the rational design of highly efficient antimicrobials for luminescence-guided antibacterial study.
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Antibacterianos , Anti-Infecciosos , Humanos , Antibacterianos/farmacologia , Ânions , Luminescência , BactériasRESUMO
Aggregation-induced emission (AIE) materials are attractive for the fabrication of high efficiency organic light-emitting diodes (OLEDs) by harnessing "hot excitons" from the high-lying triplet exciton states (Tn, n ≥ 2) and high photoluminescence (PL) quantum efficiency in solid films. However, the electroluminescence (EL) efficiency of most AIE-based OLEDs does not meet our expectation due to some unrevealed exciton loss processes. Herein, we further enhance the efficiency of blue AIE-based OLEDs, and find experimentally and theoretically that the serious exciton loss is caused by the quenching of radiative singlet excitons and long-lived triplet excitons [singlet-triplet annihilation (STA)]. In order to suppress the STA process, 1-(2,5-dimethyl-4-(1-pyrenyl)phenyl)pyrene (DMPPP) with triplet-triplet annihilation up-conversion was doped in two AIE emitters to reduce the triplet excitons on the lowest triplet excited state (T1) of AIE molecules. It can be seen that the external quantum efficiency (EQE) of the resulting blue OLEDs was enhanced to 11.8% with CIE coordinates of (0.15, 0.07) and a negligible efficiency roll-off, realizing the efficiency breakthrough of deep-blue AIE-based OLEDs. This work establishes a physical insight in revealing the exciton loss processes and the fabrication of high-performance AIE-based OLEDs.