Coordination-Induced Emission from Tetraphenylethylene Units and Their Applications

Thanks to the potential of aggregation-induced emission (AIE) phenomena, improved stabilities, and the good selectivity and sensitivity of the chemical responses exhibited by the products, coordination-driven self-assembly with tetraphenylethylene (TPE) units has recently received much attention and has been widely investigated for application in chemical sensors, cell imaging agents, light-harvesting systems, and others. Several reviews have emerged on the topics of AIE chemistry and aggregation-induced emission luminogen (AIEgen)-based supramolecular assembles, however, there is still a distinct lack of full overviews of emission enhancement from the viewpoint of metal-coordination effects. Thus, this minireview offers recent advances that have been made in the design and application of TPE-based metallacycles, metallacages, metal-organic frameworks (MOFs) and coordination polymers (CPs).

Supramolecular Fluorescent Sensors: An Historical Overview and Update

Since as early as 1867, molecular sensors have been recognized as being intelligent "devices" capable of addressing a variety of issues related to our environment and health (e.g., the detection of toxic pollutants or disease-related biomarkers). In this review, we focus on fluorescence-based sensors that incorporate supramolecular chemistry to achieve a desired sensing outcome. The goal is to provide an illustrative overview, rather than a comprehensive listing of all that has been done in the field. We will thus summarize early work devoted to the development of supramolecular fluorescent sensors and provide an update on recent advances in the area (mostly from 2018 onward). A particular emphasis will be placed on design strategies that may be exploited for analyte sensing and corresponding molecular platforms. Supramolecular approaches considered include, inter alia, binding-based sensing (BBS) and indicator displacement assays (IDAs). Because it has traditionally received less treatment, many of the illustrative examples chosen will involve anion sensing. Finally, this review will also include our perspectives on the future directions of the field.

Anion-binding-induced and reduced fluorescence emission (ABIFE & ABRFE): A fluorescent chemo sensor for selective turn-on/off detection of cyanide and fluoride

A new hydrazine based π-hole assisted, electron deficient turn-on/off fluorescent and colorimetric sensor L with anion-binding induced/reduced fluorescent emission (ABIFE & ABRFE) has been designed and synthesized. The prepared sensor L exhibited excellent turn-on fluorescence emission in the presence of cyanide ion through ABIFE. On the other hand, the receptor L turns-off its fluorescence intensity upon binding with fluoride; however, the reduced emission intensity of this complex of L is recovered by addition of cyanide. The sensor L is almost intact with other tested anions. To the best of our knowledge, this is the first report on sensing of cyanide and fluoride by a neutral hydrazine based receptor via anion-binding-induced fluorescence emission (ABIFE) and anion-binding-reduced fluorescence emission (ABRFE) mechanisms respectively. The observed ABIFE and ABRFE phenomena of L with cyanide is further supported by UV-Vis, Emission, ¹H NMR and IR spectroscopic studies.

Fluorescent Probes for Selective Recognition of Hypobromous Acid: Achievements and Future Perspectives

Reactive oxygen species (ROS) have been implicated in numerous pathological processes and their homeostasis facilitates the dynamic balance of intracellular redox states. Among ROS, hypobromous acid (HOBr) has a high similarity to hypochlorous acid (HOCl) in both chemical and physical properties, whereas it has received relatively little attention. Meanwhile, selective recognition of endogenous HOBr suffers great challenges due to the fact that the concentration of this molecule is much lower than that of HOCl. Fluorescence-based detection systems have emerged as very important tools to monitor biomolecules in living cells and organisms owing to distinct advantages, particularly the temporal and spatial sampling for in vivo imaging applications. To date, the development of HOBr-specific fluorescent probes is still proceeding quite slowly, and the research related to this area has not been systematically summarized. In this review, we are the first to review the progress made so far in fluorescent probes for selective recognition and detection of HOBr. The molecular structures, sensing mechanisms, and their successful applications of these probes as bioimaging agents are discussed here in detail. Importantly, we hope this review will call for more attention to this rising field, and that this could stimulate new future achievements.

In situ formation of tetraphenylethylene nano-structures on microgels inside living cells via reduction-responsive self-assembly

Controlling the assembly of synthetic molecules in living systems is of significance for their adaptive applications. However, it is difficult to achieve, especially for composite self-assemblies, due to the complexity and dynamic change of the intracellular environment, and there exist technical difficulties for the direct visualization of organic and polymer self-assemblies. Herein, we demonstrate a novel strategy for the in situ formation of self-assembled micro-nano composite structures in a cell milieu using reduction-responsive microgels (MGs) as a platform. The MGs were prepared by a templating and crosslinking method using a synthetic amphiphlic polymer as the basic material and porous CaCO3 microparticles as the template. The aggregation-induced emission (AIE) tetraphenylethylene moieties and reduction-labile disulfide bonds in the MGs were employed as the self-assembly building blocks and triggering sites for the intracellular self-assembly, respectively. In the presence of reductive agents such as glutathione, nano-spikes were gradually formed on the MGs. After the MGs were internalized by cells, the in situ formation of microgel/nano-spike composite structures was evidenced by the enhanced fluorescence intensity and was further confirmed by direct transmission electron microscopy observation. This work provides an effective strategy to cope with the challenging task of achieving and probing controlled self-assembly in a cell milieu, leading to new insights into investigating biological self-assembly and promoting the development of micro-/nanomaterials by learning from nature.

The inspiration and challenge for through-space charge transfer architecture: from thermally activated delayed fluorescence to non-linear optical properties

Organic molecules consisting of electron donor (D) and electron acceptor (A) subunits linked by π-conjugated bridges are promising building blocks for thermally activated delayed fluorescence (TADF) and non-linear optics (NLO) materials due to their intramolecular charge transfer (CT) processes in response to external stimuli. According to the electron interaction pattern, the CT process in D-π-A architectures can be divided into two categories, through-bond/-space charge transfer (TB/TSCT). To date, research into the TADF properties of TSCT characteristic molecules has since seen significant growth. In fact, TSCT characteristic materials show great advantages in such NLO responses. In this perspective, we first briefly introduced the basic principles of NLO and TADF effects. Successively, we discuss the influence of TBCT and TSCT patterns on NLO and TADF properties, especially for TSCT characteristic. In the final part, we address the diversity and potential advantages of TSCT characteristic molecules as high-performance NLO materials. With these, it is expected that the greater structural flexibility of spatial conjugation can bring more functionality to NLO materials in the future.

Pillararene-based AIEgens: research progress and appealing applications

The pillararene-based AIEgens and AIE materials, constructed using different assembly forms, show attractive applications in various areas.

The design of dihalogenated TPE monoboronate complexes as mechanofluorochromic crystals

Mechanofluorochromic crystals based on tetraphenylethylene and boronates reversibly change their emission upon grinding, setting the path to develop bistable switches in the future.

Supramolecular polymorphism in aggregates of a boron-difluoride complex of peri-naphthoindigo via solvent- and pathway-dependent self-assembly

Supramolecular polymorphism, a rare phenomenon, has been demonstrated using BF2-coordinated peri-naphthoindigo.

Functional Polymer Systems with Aggregation-Induced Emission and Stimuli Responses

Functional polymer systems with stimuli responses have attracted great attention over the years due to their diverse range of applications. Such polymers are capable of altering their chemical and/or physical properties, such as chemical structures, chain conformation, solubility, shape, morphologies, and optical properties, in response to single or multiple stimuli. Among various stimuli-responsive polymers, those with aggregation-induced emission (AIE) properties possess the advantages of high sensitivity, fast response, large contrast, excellent photostability, and low background noise. The changes in fluorescence signal can be conveniently detected and monitored using portable instruments. The integration of AIE and stimuli responses into one polymer system provides a feasible and effective strategy for the development of smart polymers with high sensitivity to environmental variations. Here, we review the recent advances in the design, preparation, performance, and applications of functional synthetic polymer systems with AIE and stimuli responses. Various AIE-based polymer systems with responsiveness toward single physical or chemical stimuli as well as multiple stimuli are summarized with specific examples. The current challenges and perspectives on the future development of this research area will also be discussed at the end of this review.

Control and Transfer of Chirality Within Well-Defined Tripodal Supramolecular Cages

The development of new strategies to turn achiral artificial hosts into highly desirable chiral receptors is a crucial challenge in order to advance the fields of asymmetric transformations and enantioselective sensing. Over the past few years, C₃ symmetrical cages have emerged as interesting class of supramolecular hosts that have been reported as efficient scaffolds for chirality dynamics (such as generation, control, and transfer). On this basis, this mini review, which summarizes the existing examples of chirality control and propagation in tripodal supramolecular cages, aims at discussing the benefits and perspectives of this approach.

AIE-active mechanoluminescent discotic liquid crystals for applications in OLEDs and bio-imaging

A multifunctional molecular design of fluorescent discotic liquid crystal (DLC) consisting of a tetraphenylethylene core is reported, which is found to serve as an excellent solid-state emitter in OLED devices with EQE of 4.4% and tunable mechanochromism. X-ray diffraction studies unveiled that change in supramolecular self-assembly is the physical origin of mechanochromism. The luminescent DLC molecule has been shown to act as a highly selective probe for labelling acidic cellular compartments (such as lysosomes) in bio-imaging using HeLa cells.

Full Visible Spectrum and White Light Emission with a Single, Input-Tunable Organic Fluorophore

The blue emission of M2biQ can be tuned to specific wavelengths throughout the visible region by changing the identity of the cation it interacts with. These optical properties are observed in MeCN solution and the solid state. White light is obtained in MeCN by using either the proper ratio of zinc ions or acid. Thus, M2biQ acts as a nearly universal emitter (λem = 468-690 nm) with large Stokes shifts (116-306 nm, Δν̃ = 7,042-11,823 cm-1). Full spectral profiles as well as quantum yields, lifetimes, and the crystal structures of key RGB and yellow emitters are reported. Emission wavelengths correlate with cationic radius, and TD-DFT calculations show that, for 1:1 complexes, the smaller the ion, the shorter the N-cation bond, and the greater the bathochromic emission shift.

Restriction of Conformation Transformation in Excited State: An Aggregation-Induced Emission Building Block Based on Stable Exocyclic C=N Group

The development of aggregation-induced emission (AIE) building block and deciphering its luminescence mechanism are of great significance. Here a feasible strategy for the construction of AIE unit based on E-Z isomerization (EZI) of exocyclic C=N double bond is proposed. Taking [1,2,4]thiadiazole[4,3-a]pyridine (TZP) derivative as an example, its aryl-substituted derivative (TZPP) shows obvious AIE character. The analysis of spectral data and theoretical calculations indicates that fast structural relaxation of TZPP in the emissive state plays a key role in a low fluorescence quantum yield in dilute solution, which should be caused by the small energy gap between locally excited (LE) state and twisted intramolecular charge transfer state. When in solid state, the bright emission with LE state characteristic reappears due to the large shift barrier of geometry transformation. As a potential building block for AIEgens with special heterocyclic structure, these findings would open up opportunities for developing various functional materials.

•

A new aggregation-induced emission building block

•

A novel AIE mechanism with spectral measurements and theoretical calculations

•

Available starting materials resulting in convenient synthesis and modification

•

A stable exocyclic C=N double bond in heterocycles

Putting Ink into Polyion Micelles: Full-Color Anticounterfeiting with Water/Organic Solvent Dual Resistance

Anticounterfeiting paintings are usually with limited colors and easy blurring and need to be dispersed in an environmentally unfriendly organic solvent. We report a set of water-based polyion micellar inks to solve all these problems. Upon complexation of reversible coordination polymers formed with rare earth metal ions Eu³⁺ and Tb³⁺ and the aggregation-induced emission ligand tetraphenylethylene-L₂EO₄ with oppositely charged block polyelectrolyte P2MVP₂₉-b-PEO₂₀₅, we are able to generate polyion micelles displaying three elementary emission colors of red (R) (Φ_Eu³⁺ = 24%), green (G) (Φ_Tb³⁺ = 7%), and blue (B) (Φ_TPE = 9%). Full-spectrum emission and white light emission (0.34, 0.34) become possible by simply mixing the R, G, and B micelles at the desired fraction. Strikingly, the micellar inks remain stable even after soaking in water or organic solvents (ethyl acetate, ethanol, etc.) for 24 h. We envision that polyion micelles would open a new paradigm in the field of anticounterfeiting.

Designing a highly stable coordination-driven metallacycle for imaging-guided photodynamic cancer theranostics

Coordination-driven self-assembly features good predictability and directionality in the construction of discrete metallacycles and metallacages with well-defined sizes and shapes, but their medicinal application has been limited by their low stability and solubility. Herein, we have designed and synthesized a highly stable coordination-driven metallacycle with desired functionality derived from a perylene-diimide ligand via a spontaneous deprotonation self-assembly process. Brilliant chemical stability and singlet oxygen production ability of this emissive octanuclear organopalladium macrocycle make it a good candidate toward biological studies. After cellular uptake by endocytosis, the metallacycle exhibits potent fluorescence cell imaging properties and cancer photodynamic therapeutic ability through enhancing ROS production, with high biocompatibility and safety. This study not only provides a rational design strategy for highly stable luminescent organopalladium metallacycles, but also sheds light on their application in imaging-guided photodynamic cancer therapy.

A highly-luminescent metallacycle with chemical stability and singlet oxygen production ability were obtained by a spontaneous deprotonation self-assembly process, which exhibits application potential in imaging-guided photodynamic cancer therapy.

Transparency and AIE tunable supramolecular polymer hydrogel acts as TEA-HCl vapor controlled smart optical material

Stimuli-responsive optical materials attract lots of attention due to their broad applications. Herein, a novel smart stimuli-responsive supramolecular polymer was successfully constructed using a simple tripodal quaternary ammonium-based gelator (TH). The TH self-assembles into a supramolecular polymer hydrogel (TH-G) and shows aggregation-induced emission (AIE) properties. Interestingly, the transparency and fluorescence of the TH-G xerogel film (TH-GF) could be reversibly regulated by use of triethylamine (TEA) and hydrochloric acid (HCl) vapor. When alternately fumed with TEA and HCl vapor, the optical transmittance of the TH-GF was changed from 8.9% to 92.7%. Meanwhile, the fluorescence of the TH-G shows an "ON/OFF" switch. The reversible switching of the transparency and the fluorescence of the TH-GF is attributed to the assembly and disassembly of the supramolecular polymer TH-G. Based on these stimuli-response properties, the TH-GF could act as an optical material and shows potential applications as smart windows or fluorescent display material controlled by TEA and HCl vapor.

Solid-state intramolecular motions in continuous fibers driven by ambient humidity for fluorescent sensors

One striking feature of molecular rotors is their ability to change conformation with detectable optical signals through molecular motion when stimulated. However, due to the strong intermolecular interactions, synthetic molecular rotors have often relied on fluid environments. Here, we take advantage of the solid-state intramolecular motion of aggregation-induced emission (AIE) molecular rotors and one-dimensional fibers, developing highly sensitive optical fiber sensors that respond to ambient humidity rapidly and reversibly with observable chromatic fluorescence change. Moisture environments induce the swelling of the polymer fibers, activating intramolecular motions of AIE molecules to result in red-shifted fluorescence and linear response to ambient humidity. In this case, polymer fiber provides a process-friendly architecture and a physically tunable medium for the embedded AIE molecules to manipulate their fluorescence response characteristics. Assembly of sensor fibers could be built into hierarchical structures, which are adaptive to diverse-configuration for spatial-temporal humidity mapping, and suitable for device integration to build light-emitting sensors as well as touchless positioning interfaces for intelligence systems.

Colorimetric fluorescent paper strip with smartphone platform for quantitative detection of cadmium ions in real samples

Instrument-free, portable and direct read-out mini-devices have wider application prospects in various fields, especially for real-time/on-site detection in environmental science. Herein, a colorimetric fluorescent sensor for detecting cadmium ions (Cd²⁺) based on aggregation-induced emission (AIE) was established, fluorescent paper strips integrated with smartphone platform was further designed for the visualization, on-site and quantitative detection of Cd²⁺. The colorimetric fluorescent sensor was prepared by mixing orange emission glutathione-stabilized gold nanoclusters (AuNCs) with blue emission ethylenediamine functionalized graphene oxide (EDA-GO), and introducing copper ions (Cu²⁺) to quench the orange emission of AuNCs while the blue emission served as a background reference without color change. The Cd²⁺ can induce Cu²⁺-GSH-AuNCs to aggregation and emit orange fluorescence, causing the fluorescent color of the sensor changed from blue to red with the limit of detection (LOD) as low as 33.3 nM in solution. Moreover, fluorescent paper strips integrated with smartphone platform has a sensitive detection of Cd²⁺ with the LOD of 0.1 μM in rice samples. The method reported here might have great application prospects in real-time monitoring of foods safety and environmental protection.

Principles of Aggregation-Induced Emission: Design of Deactivation Pathways for Advanced AIEgens and Applications

Twenty years ago, the concept of aggregation-induced emission (AIE) was proposed, and this unique luminescent property has attracted scientific interest ever since. However, AIE denominates only the phenomenon, while the details of its underlying guiding principles remain to be elucidated. This minireview discusses the basic principles of AIE based on our previous mechanistic study of the photophysical behavior of 9,10-bis(N,N-dialkylamino)anthracene (BDAA) and the corresponding mechanistic analysis by quantum chemical calculations. BDAA comprises an anthracene core and small electron donors, which allows the quantum chemical aspects of AIE to be discussed. The key factor for AIE is the control over the non-radiative decay (deactivation) pathway, which can be visualized by considering the conical intersection (CI) on a potential energy surface. Controlling the conical intersection (CI) on the potential energy surface enables the separate formation of fluorescent (CI:high) and non-fluorescent (CI:low) molecules [control of conical intersection accessibility (CCIA)]. The novelty and originality of AIE in the field of photochemistry lies in the creation of functionality by design and in the active control over deactivation pathways. Moreover, we provide a new design strategy for AIE luminogens (AIEgens) and discuss selected examples.

Equipment-free and visual detection of multiple biomarkers via an aggregation induced emission luminogen-based paper biosensor

Early and accurate disease diagnosis is of great appeal for saving patients' life, but requires biomarkers to be sensitively detected with simplicity, convenience, and low cost. Exploring the development of a high-performance fluorescence biosensor for biomarkers solid, equipment-free and visual biosensing is highly urgent but faces enormous challenges. Herein, we proposed a brand-new fluorescence system by integrating a typical aggregation induced emission dye (TPE-BTD) with dopamine for multiple biomarkers sensitive detection based on target-induced catalyzing oxidation. The system comprising TPE-BTD and dopamine emits strong fluorescence; with horseradish peroxidase (HRP) or HRP-mimicking DNAzyme and H₂O₂ being added, significant oxidation on dopamine occurs to generate dopachrome, which actuated the inner filter effect (IFE) due to the overlap of its absorbtion curve and emission spectrum of TPE-BTD, subsequently decreasing fluorescence emission and displaying a rapid and sensitive response to H₂O₂ and G-quadruplex DNA. We further apply TPE-BTD/dopamine system in analysis of glucose and DNA adenine methylation methyltransferase (Dam MTase) based on target-initiated signal transduction. Finally, TPE-BTD was employed as emitters in fabrication of paper biosensors, which can achieve solid, equipment-free and visual detection of multiple biomarkers based on the high emission performance of TPE-BTD, opening up a new pathway to development of biosensors for practical application. We expect this sensing conception will be helpful in development of practical biosensors, and this sensor will find more applications in disease diagnosis.

Silver-Driven Coordination Self-Assembly of Tetraphenylethene Stereoisomer: Construct Charming Topologies and Their Mechanochromic Behaviors

A series of silver coordination complexes (CCs) have been synthesized through self-assembly of five pyridine-substituted tetraphenylethylene stereoisomer ligands with silver ions (named Ag-TPE-2by-1-E, Ag-TPE-2by-2-E, Ag-TPE-2by-2-Z, Ag-TPE-2by-3-E, and Ag-TPE-2by-3-Z). These silver CCs show distinct topologies including beaded chain frameworks, linear structures, and discrete metallacycles. The single-crystal analysis results reveal the critical role of the space distribution of the coordination site and stereoisomer ligands in controlling the silver CCs' geometry configuration and modulating the optical properties. Luminescent investigations revealed that Ag-TPE-2by-2-E, Ag-TPE-2by-2-Z, Ag-TPE-2by-3-E, and Ag-TPE-2by-3-Z possess obvious mechanocharomic behaviors, which can be achieved several reversible cycles through repeated grinding and methanol soaking processes. However, the Ag-TPE-2by-1-E showed tenacious stability toward mechanical grinding and temperature. Thus, these silver CCs provide a good platform to investigate the influence of the space distribution of the coordination site of ligands on their geometry and mechanocharomic properties.

Well-Defined Conjugated Macromolecules Based on Oligo(Arylene Ethynylene)s in Sensing

Macromolecules with well-defined structures in terms of molar mass and monomer sequence became interesting building blocks for modern materials. The precision of the macromolecular structure makes fine-tuning of the properties of resulting materials possible. Conjugated macromolecules exhibit excellent optoelectronic properties that make them exceptional candidates for sensor construction. The importance of chain length and monomer sequence is particularly important in conjugated systems. The oligomer length, monomer sequence, and structural modification often influence the energy bang gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the molecules that reflect in their properties. Moreover, the supramolecular aggregation that is often observed in oligo-conjugated systems is usually strongly affected by even minor structural changes that are used for sensor designs. This review discusses the examples of well-defined conjugated macromolecules based on oligo(arylene ethynylene) skeleton used for sensor applications. Here, exclusively examples of uniform macromolecules are summarized. The sensing mechanisms and importance of uniformity of structure are deliberated.

An AIEgen-based 2D ultrathin metal-organic layer as an electrochemiluminescence platform for ultrasensitive biosensing of carcinoembryonic antigen

In this work, a novel two-dimensional (2D) ultrathin metal-organic layer (MOL) based on the aggregation-induced emission (AIE) ligand H4ETTC (H4ETTC = 4',4''',4''''',4'''''''-(ethene-1,1,2,2-tetrayl)tetrakis(([1,1'-biphenyl]-4-carboxylic acid))) was developed and used to construct a novel electrochemiluminescence (ECL) aptasensor for ultrasensitive detection of carcinoembryonic antigen (CEA). The newly synthesized AIE luminogen (AIEgen)-based MOL (Hf-ETTC-MOL) yielded a higher ECL intensity and efficiency than did H4ETTC monomers, H4ETTC aggregates and 3D bulk Hf-ETTC-MOF. This improvement occurred not only because the ETTC ligands were coordinatively immobilized in a rigid MOL matrix, which restricted the intramolecular free rotation and vibration of these ligands and then reduced the non-radiative transition, but also because the porous ultrathin 2D MOL greatly shortened the transport distances of ions, electrons, coreactant (triethylamine, TEA) and coreactant intermediates (TEA˙ and TEA˙+), which made more ETTC luminophores able to be excited and yielded a high ECL efficiency. On the basis of using the Hf-ETTC-MOL as a novel ECL emitter and rolling circle amplification (RCA) as a signal amplification strategy, the constructed ECL aptasensor exhibited a linear range from 1 fg mL-1 to 1 ng mL-1 with a detection limit of 0.63 fg mL-1. This work has opened up new prospects for developing novel ECL materials and is expected to lead to increased interest in using AIEgen-based MOLs for ECL sensing.

First demonstration of the π-f orbital interaction depending on the coordination geometry in Eu(iii) luminophores

Herein, the π-f orbital interaction depending on the coordination geometry in the Eu(iii) complex is demonstrated. Thermal analysis and computational calculations showed the phase transition of the Eu(iii) complex based on the change in the coordination geometry. A red-shifted LMCT band and radiative rate changes associated with the phase transition were found in the Eu(iii) complex.

Chiral auxiliary and induced chiroptical sensing with 5d/4f lanthanide-organic macrocycles

A stereocontrolled self-assembly of 5d/4f heterometal-organic macrocycles has been realized by a post-assembly chiral auxiliary approach. Interligand π-π stacking interactions promoted chiral transfer from point-chirality of the auxiliary ligand to metal centers and then the helicates to produced CD and CPL active europium assemblies, facilitating a feasible enantiomeric excess determination by induced chiroptical signals.

Supramolecular materials based on AIE luminogens (AIEgens): construction and applications

The emergence of aggregation-induced emission luminogens (AIEgens) has significantly stimulated the development of luminescent supramolecular materials because their strong emissions in the aggregated state have resolved the notorious obstacle of the aggregation-caused quenching (ACQ) effect, thereby enabling AIEgen-based supramolecular materials to have a promising prospect in the fields of luminescent materials, sensors, bioimaging, drug delivery, and theranostics. Moreover, in contrast to conventional fluorescent molecules, the configuration of AIEgens is highly twisted in space. Investigating AIEgens and the corresponding supramolecular materials provides fundamental insights into the self-assembly of nonplanar molecules, drastically expands the building blocks of supramolecular materials, and pushes forward the frontiers of supramolecular chemistry. In this review, we will summarize the basic concepts, seminal studies, recent trends, and perspectives in the construction and applications of AIEgen-based supramolecular materials with the hope to inspire more interest and additional ideas from researchers and further advance the development of supramolecular chemistry.