Aggregation-induced Emission Characteristics Research Articles

High-contrast tricolor-tunable solid luminescent AIE-active Au(I) isocyanide complexes based on thermo- and mechanochromism

Breaking through the limitations of traditional luminescent materials, integrating the charming aggregation-induced emission (AIE) characteristics, high-contrast mechanochromism and thermochromism into one molecule is of great significance to make stimuli-responsive materials more intelligent. Herein, two Au(I) isocyanide complexes with short alkoxyl chains (C2 and C3) in the solid state are designed and synthesized, the length of the alkoxyl chain exerts significant impacts on molecular arrangement. Both C2 and C3 exhibit obvious AIE properties, the green luminescent aggregate of C2 and C3 is result from J-aggregation while the orange luminescent aggregate of C3 is result from the formation of aurophilic bonds, which supported by the single crystal X-ray analysis. Moreover, C2 and C3 not only display red-shifted mechanochromism (20 nm and 26 nm), but also exhibit gradual blue-shifted thermochromism. A tricolored luminescent switch application was demonstrated using C3 as a multi-stimuli responsive material. This molecular design strategy provides a new avenue for efficient luminescent materials with AIE and multi-stimuli responsive properties.

Discovery of Fluorescent Naturally-occurring Inhibitor of SARS-CoV-2 Main Protease By AIE Fluorescent Probe.

Target-based high-throughput screening (HTS) is an efficient way to identify potent drugs. However, the accuracy of HTS could be affected by Pan-Assay Interference Compounds (PAINS). One reason for the generation of PAINS is that the inherent photophysical property of screened compounds could interfere with typically used assay signals including absorption and fluorescence. Our previous studies indicate that the fluorescent probe based on the fluorophore with characteristics of aggregation-induced emission (AIE) could provide high accuracy of HTS, especially for the fluorescent natural products. Herein, we report an AIE-based fluorescent probe for the main protease (Mpro) of SARS-CoV-2. We designed and synthesized an AIE fluorescent probe ZLHG5, which has a site that can be specifically cleaved by Mpro to produce a light-up fluorescence. Thanks to the large Stokes shift of AIE fluorophore (~300 nm), the probe could be effectively used for HTS of Mpro inhibitors. After screening a library of fluorescent natural products with ZLHG5, we obtained two coumarin-originated natural compounds with potent inhibitory activity towards Mpro protease. This study provides both useful fluorescent HTS probe and potent inhibitors for Mpro protease.

Enhanced chemiluminescence resonance energy transfer using surfactant-modified AIE carbon dots.

Chemiluminescence resonance energy transfer (CRET) efficiency can be enhanced by confining CRET donors and acceptors within nanoscale spaces. However, this enhanced efficiency is often affected by uncertainties stemming from the random distribution of CRET donors and acceptors in such confined environments. In this study, a novel confined nanospace was created through the surfactant modification of carbon dots (CDs) exhibiting aggregation-induced emission (AIE) characteristics. Hydrophobic CRET donors could be effectively confined within this nanospace. The distance between the CRET donors and acceptors could be controlled by anchoring the AIE-CDs as the CRET acceptors, resulting in significantly improved CRET efficiency. Furthermore, this AIE-CDs-based CRET system was successfully applied to the detection of hydrogen peroxide (H2O2) in rainwater, showcasing its potential for practical applications.

ESIPT-associated fluorescent property and AIE characteristic of multifunctional nanoprobe DPNAP

The DPNAP is a multifunctional nanoprobe designed for selective illumination of fungi and targeted antimicrobial applications. By introducing hydroxyl groups into the DPNAP, the aggregation-induced emission (AIE) characteristic can be obtained. However, its optical properties and underlying theoretical mechanisms are not fully understood. In this work, we explored the stable DPNAP configurations by constructing the potential energy surfaces and elucidated the mechanism of the proton transfer reaction. Our findings indicate that proton transfer occurs through a stepwise reaction with energy barriers of < 10 kcal/mol, owing to the variation in hydrogen-bonding strength as revealed by hydrogen-bond parameters and infrared vibrational analyses. The theoretical fluorescence peak (λcal = 541 nm) based on the optimized structures is consistent with the experimental peak (λexp = 500 nm). The experimental single-fluorescence band is attributed to the overlap of emission spectra of normal structure and single- and double-proton transfer isomers. Moreover, the hydroxyl-induced AIE mechanism is attributed to increased molecular planarity and restricted intramolecular charge transfer in the aggregate state. Understanding of the AIE characteristic and ESIPT mechanism is of fundamental importance in molecular electronics and photonics, and is also beneficial to the development of novel biomedical materials.

De Novo Synthesis of 2,2'-Bipyridines and Related Bis-azines via Cascade Coupling and Double Pyridannulation of Isocyanides.

Herein, we present a new and general protocol for the assembly of 2,2'-bipyridyls from nonpyridine substrates without using any metal catalysts or organometallic reagents. The process starts from the coupling of two 1,3-dienyl isocyanides followed by a 6π-electrocyclization/aromatization cascade featuring the simultaneous formation of two pyridine rings in a single operation. Notably, this strategy is also applicable to the construction of nonsymmetrical 2-(2-pyridyl)-quinolines/-quinoxalines. Furthermore, the aggregation-induced emission (AIE) characteristics endow our approach with great potential in biorelevant fields.

A novel red-to-near-infrared AIE fluorescent probe for detection of Hg2+ with large Stokes shift in plant and living cells

Due to the highly toxic nature of mercury ions to living organisms, accurately detecting Hg2+ in water samples and biological systems is of great significance. In this study, we designed and synthesized a novel red-to-near-infrared Aggregation-Induced Emission (AIE) fluorescent probe (named as DS) based Fluorene derivatives on specifically for Hg2+ detection. Probe DS can visually identify Hg2+ through an red-to-near-infrared fluorescence enhancement change, characterized by a large Stokes shift (130 nm) and AIE feature. This probe offers a fast response, high selectivity and sensitivity. The Hg2+-induced deprotection reaction of the thioketal mechanism was thoroughly investigated using nuclear magnetic resonance spectroscopy (NMR), mass spectrometry (MS) and density functional theory (DFT) calculation. Additionly, dynamic light scattering (DLS) results indicated that the aggregation states changes of the molecular play a crucial role in the AIE fluorescence response of probe DS toward Hg2+. The red-to-near-infrared response with AIE feature not only avoids the interference of auto-fluorescence signals in complex environments, but also reduces the fluorescence quenching caused by probe molecular aggregation. This makes probe DS highly suitable for high-quality imaging detection of Hg2+ in aqueous environments. Furthermore, probe DS demonstrates the capability for visual fluorescence detection of Hg2+ concentrations in water sample, plant roots and living cells.

Assembly‐Driven Aggregation‐Induced Emission of Gold Nanoclusters with Excitation Wavelength‐Dependent Emission and Mechanochromic Property

AbstractMetal nanoclusters with aggregation‐induced emission (AIE) characteristics are potential nanomaterial candidates for a wide array of advanced optical applications. In this study, a novel self‐assembly enhanced AIE strategy utilizing 6‐thioguanine (TG)‐protected gold nanoclusters (AuNCs) is fabricated with dual‐stimuli responsive modes of excitation wavelength‐dependent (Ex‐De) emission and mechanochromic properties. The sheetlike structures of AuNCs self‐assembly (AuNC sheets) with typical AIE characteristics are generated in bad solvent owing to the intermolecular hydrogen‐bonds interaction among guanine‐rich moieties of TG ligand. Interestingly, the maximum emission peaks of AuNC sheets are red‐shifted with the increased excitation wavelengths, indicating Ex‐De emission behavior. This phenomenon enables the achievement of wide‐range tunable photoluminescence (PL). In addition, the emission peak of AuNC sheets powders before and after grinding displays the bathochromic shift of 110 nm. The “off–on” switch of Ex‐De emission behavior in AuNC sheets can be manipulated by changing mechanical pressure. It is speculated that the tunable PL behavior of AuNC sheets originates from multiple excited states due to the existence of different Au(I)···Au(I) distances. The self‐assembly‐driven AIE strategy of AuNCs with stimuli‐responsive allochroic modes will facilitate the recording of rewritable information, opening up a new avenue for high‐throughput and multi‐dimensional optical security.

Fluorogenic in-situ Labelling of Gelatin Polymer in Aqueous Solution and Hydrogel.

Gelatin polymers made from partially degraded collagen are important biomaterials, but their in-situ analysis suffers from uncontrollable covalent labelling and poor spatial-temporal imaging resolution. Herein, three tetrazolate-tagged tetraphenylethylene fluorophores (TPE-TAs) are introduced for practical fluorogenic labelling of gelatin in aqueous phase and hydrogels. These probes with aggregation-induced emission characteristics offer negligible background and elicit turn-on fluorescence by simply mixing with the gelatin in aqueous phase, giving a detection limit of 0.15 mg/L over a linear dynamic range up to 100 mg/L. This method does not work for collagens and causes minimal interference with gelatin properties. Mechanistic studies reveal a key role for multivalent electrostatic interactions between the abundant basic residues in gelatin (e. g., lysine, hydroxylysine, arginine) and anionic tetrazolate moieties of the lipophilic fluorophore synergistically in spatially rigid macromolecular encapsulation to achieve fluorogenic labelling. The AIE strategy by forming non-covalent fluorophore-gelatin complexes was developed for novel hydrogels that exhibited reversible fluorescence in response to dynamic microstructural changes in the hydrogel scaffold upon salting-in/out treatments, and enabled high spatial-temporal imaging of the fiber network in lyophilized samples. This work may open up avenues for in-situ imaging analysis and evaluation of gelatin-based biomaterials during processes such as in vivo degradation and mineralization.

Uncovering the Aggregation-Induced Emission Mechanisms of Phenoxazine and Phenothiazine Groups.

Molecules with both aggregation-induced emission (AIE) and thermally activated delayed fluorescence (TADF) properties are potential organic light-emitting diode materials; however, the AIE and TADF mechanisms are still debatable. In this work, four molecules incorporating carbazole (Cz), phenoxazine (PXZ), and phenothiazine (PTZ) as donor groups to the diphenylsulfone acceptor were investigated. The experiment results indicate that a molecule containing Cz exhibits solely TADF properties, whereas molecules containing PXZ and PTZ demonstrate both TADF and AIE characteristics. As for DPS-PTZ, the result indicates that the thin-film environment restricts molecular twisting, consequently reducing nonradiative decay, thereby attributing to the AIE property by density functional theory and molecular dynamics simulation. As for DPS-PXZ, the result suggests that the restricted access to a conical intersection in a singlet excited via an expansion in the C-S-C angle is the pivotal factor for the AIE characteristic. The C-S-C angle twist of DPS-PXZ is impeded in the aggregate state and resulted in luminescence. Understanding the mechanisms serves as a valuable guide for the development of new AIE systems, enabling their application in various practical domains.

Colorimetric/fluorescent dual-mode assay for antioxidant capacity of gallnuts based on CuCo nanozyme and AIE luminogen

In this work, we present a dual-mode assay system consisting of a nanozyme and a luminogen with the aggregation-induced emission (AIE) feature. In the assay system, the chosen nanozyme named CuCo-0 catalyzes the substrate to produce colorimetric signals, while the aggregates of H4ETTC (4,4′,4″,4‴-(ethene-1,1,2,2-tetrayl) tetrakis ([1,1′-biphenyl]-4-carboxylic acid), a typical AIE luminogen, generate fluorescent signals. The peroxidase-like activity of the CuCo-0 nanozyme can be remarkably suppressed with sequential additions of antioxidants, leading to a dual-signal response characterized by enhanced fluorescence emission and reduced UV-vis absorbance. On this basis, a dual-mode assay capable of producing both colorimetric and fluorescent signals for the assessment of antioxidant capacity using gallic acid as a representative antioxidant was exploited. Good linearity can be obtained in the 0–60 μM range for both colorimetric analysis and fluorescent analysis, with detection limits of 1.3 μM and 0.35 μM, respectively. Furthermore, this dual-mode assay was successfully applied to real gallnut samples, yielding satisfactory results.

AIE-ESIPT Photoluminescent Probe Based on 3-(3-Hydroxypyridin-2-yl)isoquinolin-4-ol for the Detection of Intracellular Hydrogen Peroxide.

Excited-state intramolecular proton transfer (ESIPT) molecules, which feature large Stokes shifts to avoid self-absorption, play an essential role in photoluminescent bioimaging probes. Herein, we report the development of an ESIPT molecule 3-(3-hydroxypyridin-2-yl)isoquinolin-4-ol (PiQ). PiQ not only undergoes a distinct ESIPT process unlike the symmetrical 2,2'-bipyridyl-3,3'-diol but also exhibits aggregation-induced emission (AIE) characteristics. PiQ self-assembles into aggregates with an average size of 241.0±51.9 nm in aqueous solutions, leading to significantly enhanced photoluminescence. On the basis of the ESIPT and AIE characteristics of PiQ, the latter is functionalized with a hydrogen peroxide-responsive 4-pinacoratoborylbenzyl group (B) and a carboxylesterase-responsive acetyl group (A) to produce a photoluminescent probe B-PiQ-A. The potential of PiQ for applications in bioimaging and chemical sensing is underscored by its efficient detection of both endogenous and exogenous hydrogen peroxide in living cells.

A structure-guided strategy to design Golgi apparatus-targeted type-I/II aggregation-induced emission photosensitizers for efficient photodynamic therapy

The Golgi apparatus (GA) is a vital target for anticancer therapy due to its sensitivity against reactive oxygen species (ROS)-induced oxidative stress that could lead to cell death. In this study, we designed a series of aggregation-induced emission (AIE)-based photosensitizers (TPAPyTZ, TPAPyTC, TPAPyTM, and TPAPyTI) carrying different ROS with selective GA-targeted ability. The in vitro study showed that TPAPyTZ and TPAPyTC displayed strong AIE characteristics, robust type-I/II ROS production capabilities, specific GA-targeted, high photostability, and high imaging quality. The cell-uptake of TPAPyTZ was found primarily through an energy-dependent caveolae/raft-mediated endocytosis pathway. Remarkably, TPAPyTZ induced GA-oxidative stress, leading to GA fragmentation, downregulation of GM130 expression, and activation of mitochondria caspase-related apoptosis during photodynamic therapy (PDT). In vivo experiments revealed that TPAPyTZ significantly inhibited tumor proliferation under lower-intensity white light irradiation with minimal side effects. Overall, our work presents a promising strategy for designing AIEgens for fluorescence imaging-guided PDT. Additionally, it enriched the collection of GA-targeted leads for the development of cancer theranostics capable of visualizing dynamic changes in the GA during cancer cell apoptosis, which could potentially enable early diagnosis applications in the future. Statement of significanceAIE luminogens (AIEgens) are potent phototheranostic agents that can exhibit strong fluorescence emission and enhance ROS production in the aggregate states. In this study, through the precise design of photosensitizers with four different electron-acceptors, we constructed a series of potent AIEgens (TPAPyTZ, TPAPyTC, TPAPyTM, and TPAPyTI) with strong fluorescence intensity and ROS generation capacity. Among them, TPAPyTZ with an extended π-conjugation displayed the strongest ROS generation ability and anti-tumor activity, resulting in an 88 % reduction in tumor weight. Our studies revealed that the enhanced activity of TPAPyTZ may be due to its unique Golgi apparatus (GA)-targeted ability, which causes GA oxidative stress followed by effective cancer cell apoptosis. This unique GA-targeted feature of TPAPyTZ remains rare in the reported AIEgens, which mainly target organelles such as lysosome, mitochondria, and cell membrane. The successful design of a GA-targeted and potent AIEgen could enrich the collection of GA-targeted luminogens, providing a lead theranostic for the further development of fluorescence imaging-guided PDT, and serving as a tool to explore the potential mechanism and discover new GA-specific drug targets.

A perylene diimide probe for NIR-II fluorescence imaging guided photothermal and type I/type II photodynamic synergistic therapy

Phototherapy has garnered significant attention in the past decade. Photothermal and photodynamic synergistic therapy combined with NIR fluorescence imaging has been one of the most attractive treatment options because of the deep tissue penetration, high selectivity and excellent therapeutic effect. Benefiting from the superb photometrics and ease of modification, perylene diimide (PDI) and its derivatives have been employed as sensing probes and therapeutic agents in the biological and biomedical research fields, and exhibiting excellent potential. Herein, we reported the development of a novel organic small-molecule phototherapeutic agent, PDI-TN. The absorption of PDI-TN extends into the NIR region, which provides feasibility for NIR phototherapy. PDI-TN overcomes the traditional Aggregation-Caused Quenching (ACQ) effect and exhibits typical characteristics of Aggregation-Induced Emission (AIE). Subsequently, PDI-TN NPs were obtained by using an amphiphilic triblock copolymer F127 to encapsulate PDI-TN. Interestingly, the PDI-TN NPs not only exhibit satisfactory photothermal effects, but also can generate O2•- and 1O2 through type I and type II pathways, respectively. Additionally, the PDI-TN NPs emit strong fluorescence in the NIR-II region, and show outstanding therapeutic potential for in vivo NIR-II fluorescence imaging. To our knowledge, PDI-TN is the first PDI derivative used for NIR-II fluorescence imaging-guided photodynamic and photothermal synergistic therapy, which suggests excellent potential for future biological/biomedical applications.

Mechano-responsive chiral gold(I) complexes with aggregation- and crystallization-induced circularly polarized luminescence

Chiral materials with circularly polarized luminescence (CPL) have attracted extensive attention due to their unique optical properties. However, it is still a challenge to obtain efficient CPL materials. In this work, noticeable CPL signals were obtained through simple crystallization in the classical aggregation-caused quenching (ACQ)-typed chloro-gold(I) complexes (R)-BINAP-AuCl and (S)-BINAP-AuCl. They exhibited typical crystallization-induced emission (CIE) and crystallization-induced CPL behaviors. Importantly, after rational modification by introducing carbazole units, the resulting carbazole-gold(I) complexes (R)-BINAP-AuCz and (S)-BINAP-AuCz showed remarkable aggregation-induced phosphorescent emission (AIPE) and unique aggregation-induced CPL characteristics due to the formation of highly ordered helical packing modes in the nano-aggregate state. More interestingly, the solids of chiral carbazole-gold(I) complexes (R)-BINAP-AuCz and (S)-BINAP-AuCz could sensitively respond to external stimuli and exhibited mechano-responsive CPL performance, which was tuned by the intermolecular C–H···π interactions. Thus, this work provided a new way for constructing high-performance and smart CPL materials.

Oligo(styryl)benzenes liposomal AIE-dots for bioimaging and phototherapy in an in vitro model of prostate cancer

Whilst the development of advanced organic dots with aggregation-induced emission characteristics (AIE-dots) is being intensively studied, their clinical translation in efficient biotherapeutic devices has yet to be tackled. This study explores the synergistic interplay of oligo(styryl)benzenes (OSBs), potent fluorogens with an increased emission in the aggregate state, and Indocyanine green (ICG) as dual Near Infrared (NIR)-visible fluorescent nanovesicles with efficient reactive oxygen species (ROS) generation capacity for cancer treatment using photodynamic therapy (PDT). The co-loading of OSBs and ICG in different nanovesicles has been thoroughly investigated. The nanovesicles’ physicochemical properties were manipulated via molecular engineering by modifying the structural properties of the lipid bilayer and the number of oligo(ethyleneoxide) chains in the OSB structure. Diffusion Ordered Spectroscopy (DOSY) NMR and spectrofluorometric studies revealed key differences in the structure of the vesicles and the arrangement of the OSB and ICG in the bilayer. The in vitro assessment of these OSB-ICG nanovesicles revealed that the formulations can increase the temperature and generate ROS after photoirradiation, showing for the first time their potential as dual photothermal/photodynamic (PTT/PDT) agents in the treatment of prostate cancer. Our study provides an exciting opportunity to extend the range of applications of OSB derivates to potentiate the toxicity of phototherapy in prostate and other types of cancer.

Anthraquinone-Centered Type I Photosensitizer with Aggregation-Induced Emission Characteristics for Tumor-Targeted Two-Photon Photodynamic Therapy

Anthraquinone-Centered Type I Photosensitizer with Aggregation-Induced Emission Characteristics for Tumor-Targeted Two-Photon Photodynamic Therapy

Donor-Acceptor Modulating of Ionic AIE Photosensitizers for Enhanced ROS Generation and NIR-II Emission.

Photosensitizers (PSs) with aggregation-induced emission (AIE) characteristics are competitive candidates for bioimaging and therapeutic applications. However, their short emission wavelength and nonspecific organelle targeting hinder their therapeutic effectiveness. Herein, a donor-acceptor modulation approach is reported to construct a series of ionic AIE photosensitizers with enhanced photodynamic therapy (PDT) outcomes and fluorescent emission in the second near-infrared (NIR-II) window. By employing dithieno[3,2-b:2',3'-d]pyrrole (DTP) and indolium (In) as the strong donor and acceptor, respectively, the compound DTP-In exhibits a substantial redshift in absorption and fluorescent emission reach to NIR-II region. The reduced energy gap between singlet and triplet states in DTP-In also increases the reactive oxygen species (ROS) generation rate. Further, DTP-In can self-assemble in aqueous solutions, forming positively charged nanoaggregates, which are superior to conventional encapsulated nanoparticles in cellular uptake and mitochondrial targeting. Consequently, DTP-In aggregates show efficient photodynamic ablation of 4T1 cancer cells and outstanding tumor theranostic in vivo under 660nm laser irradiation. This work highlights the potential of molecular engineering of donor-acceptor AIE PSs with multiple functionalities, thereby facilitating the development of more effective strategies for cancer therapy.

GFP chromophore derived amphiphiles containing [12]aneN3 and biotin moieties as bio-imaging and targeting nonviral gene vectors

Gene therapy is a promising treatment, that brings the necessary opportunity to cure human genetic and major diseases, but it is hampered by the lack of safe and efficient gene delivery vectors. In this study, four amphiphiles were derived from GFP chromophore benzylimidazolidinone (G) through modifications with oxypropyl (1) or methylene (2) linked di(triazole-[12]aneN3) (M) in the presence or absence of tumor-targeting biotin (B) moiety, GMB-1/2 and GM-1/2. The four compounds showed excellent aggregation-induced emission (AIE) characteristics, strong DNA condensation abilities, and good biocompatibility. Among them, GMB-1, which containing targeting biotin moiety and a flexible propoxy linker, showed the highest transfection efficiency in three cell lines. The luciferase transfection efficiency of GMB-1 was as high as 15.2 times that of Lipofectamine 2000 (Lipo2000) without auxiliary lipid DOPE, and its gene therapy effect of delivering the p53 gene was also significantly better than that of Lipo2000 in HeLa cells due to its obvious targeting property. Fluorescence tracing experiments indicated that GMB-1 was able to quickly carry DNA into cells, to successfully escape from lysosomes, then to release DNA, and at last to smoothly deliver DNA into the nucleus. Moreover, its EGFP transfection efficiency in zebrafish reached 1.7 times that of Lipo2000. The excellent performance of GMB-1 demonstrated that the appreciative incorporation of GFP chromophore, di(triazole-[12]aneN3), and biotin moieties into the nonviral gene vectors provided a promising strategy for their clinical applications.

Versatile aggregation induced emissive molecular probes incorporating different donor/acceptor groups for tunable multiple color fluorescence

Excited state intramolecular proton transfer (ESIPT) and aggregation induced emission active multicolour fluorescent probes for bioimaging applications has grown popularly in recent years. Herein, we report a series of different donor/acceptor units (Cl, NO2 and O–CH3) bearing anthracene-salicylaldehyde based fluorescent probes and their antibacterial activity and fluorescence imaging of E. Coli bacteria and zebrafish embryos. All the compounds (ASA1, ASA2, ASA3 and ASA4) synthesized via facile one pot condensation reaction of anthracene hydrazide with Salicylaldehyde, 5-Chlorosalicylaldehyde, 5-Nitrosalicylaldehyde, 5-methoxysalicylaldehyde and characterized using all the possible spectroscopic techniques. The noteworthy tuneable emission wavelength shifts from 471 nm to 625 nm and ESIPT characteristics of the compounds were demonstrated through photophysical experiments and single crystal X-ray diffraction analysis. All the experimental results were completely analyzed theoretically on the ground as well as the excited state using density functional theory (DFT) and time dependent density functional theory (TD-DFT) calculations. Compounds ASA1-ASA4 showed fascinating different colour fluorescent (Green, Yellow and Orange) aggregation induced emission features in the THF-H2O mixture. AIE characteristics of ASA1, ASA2, ASA3 and ASA4 were recognized using absorption, emission, fluorescence quantum yield (Φ), DLS and SEM analysis. ASA1, ASA2, ASA3 and ASA4 showed excellent antibacterial activity and ROS generation against E. Coli bacteria. Further, owing to their multicolour fluorescent property all the compounds successfully applied for fluorescent imaging in E. Coli bacteria and live zebrafish embryos.

Enzymatic fluorescent supramolecular hydrogel with aggregation-induced emission characteristics for sensing alkaline phosphatase

Alkaline phosphatase is an important biomarker for medical diagnosis. An enzymatic fluorescence supramolecular hydrogel with AIE properties was developed and used for sensing alkaline phosphatase in vitro and in living cells. In the presence of ALP, K(TPE)EFYp was partially converted to the hydrogelator K(TPE)EFY and self-assembled into nanofibers to form Hydrogel. With the sol–gel transition and the AIE effect, the fluorescence emission was turned on. The linear concentration range of ALP activity in vitro quantified by this method was determined as 0–3 U/L with aLODat 0.02 U/L. In addition, cell imaging and serum experiment showed that K(TPE)EFYp could also be used to detect ALP activity in living cells and biological samples.