Aggregation-induced emission of 1-methyl-1,2,3,4,5-pentaphenylsilole

Hydrogen Bonding-Induced Inversion and Amplification of Circularly Polarized Luminescence (CPL) in Supramolecular Assemblies of Axially Chiral Luminogens

Herein, we report the self-assembly and chiroptical properties of two axially chiral π-conjugated luminogens, R-NMI and S-NMI, each equipped with two pyridyl moieties for hydrogen (H)-bonding with chiral diacids. The two enantiomers display aggregation-induced emission enhancement (AIEE) and increased CD and CPL signals in the self-assembled state with a high glum value of 1.5 (±0.06)×10-2 in 1:9 dioxane:methylcyclohexane. Crystallographic analysis confirmed mirror-image helical structures for R-NMI and S-NMI involving both intra- and intermolecular π-π stacking, leading to elongated hexagonal platelets. Supramolecular co-assembly of R-NMI with D- and L-tartaric acids (D-TA and L-TA) could remarkably modulate and invert the chiroptical properties of R-NMI, which is unachievable with control chiral monoacids. The co-assembled structures were driven by pyridine-carboxylic acid H-bonding as revealed from the crystal structure analysis, which was also supported by computational studies. Strikingly, R-NMI+D-TA leads to an exceptionally high fourfold amplification in the glum value [5.4 (±0.04)×10-2] with an inverted sign, which additionally demonstrates intriguing temperature-dependent switching. In contrast, R-NMI+L-TA results in a threefold reduction in the glum value [0.54 (±0.015)×10-3], also with an inverted sign compared to R-NMI alone, establishing a clear strategy for chiral discrimination between the two enantiomers of TA.

Flexible Regulation of Optical Properties Based on Structure Size-Driven Intermolecular Interactions for Phototherapy

The precise control of optical properties in molecular systems remains a challenge for phototherapy. Herein, the strategic combination of aggregation-caused quenching (ACQ) and aggregation-induced emission (AIE) molecule creates ACQ@AIE bimolecular systems with tunable optical properties, which are almost unattainable by single-component materials. Through systematic investigation of three ACQ@AIE bimolecular systems, it is established that molecule structure size differentials dictate their intermolecular interactions and consequent optical behaviors. Crucially, AIE molecule with a smaller structure size promotes ACQ molecule clustering to enhance the photothermal effect, while when the size becomes larger, particularly approaching that of ACQ molecule, facilitating π-π stacking and boosting the photodynamic effect. These distinct assembly modes revealed through combined experimental and theoretical analyses, enable precise regulation of photothermal versus photodynamic effects by simply regulating the structure size and ratio of ACQ and AIE molecules. Building on these mechanistic insights, the optimal molecule combination of ACQ@AIE bimolecular system is engineered into nanoparticles that exhibit mild photothermal effect, strong photodynamic effect, and excellent tumor accumulation and retention, achieving near-complete tumor eradication with minimal treatment cycles while maintaining good biosafety. This work not only elucidates the fundamental structure size-interaction-property relationships in ACQ@AIE bimolecular systems but also provides generalizable strategies for developing intelligent photo theranostic materials through controlled intermolecular interaction.

Dipyrroethene-Based Red-Light Emissive AIEgens

Aggregation-induced emission (AIE) molecules find myriads of applications in various fields ranging from biomedical probes and chemical sensors to optoelectronics. In this domain, tetraphenylethene (TPE) and its derivatives have long been a benchmark due to their unique luminescent properties in aggregated states. However, the limited tunability through further functionalization and the absorption and emission spectrum in higher-energy regions constrain their applications from multiple domains. To address these limitations, we have designed a new class of highly symmetric red-light emissive AIE-active molecules by structurally engineering the E-dipyrroethene (DPE) skeleton. This design enables pre- and postsynthetic modification opportunities through the two pyrrole rings and multiple heteroatoms, facilitating tunable photophysical properties. In this context, DPE-based AIEgens Tz and BTz were synthesized through the selective α,α-diformylation of DPE followed by condensation with 2-aminothiazole and 2-aminobenzothiazole, respectively. The π-extended conjugation systems in Tz and BTz containing multiple heteroatoms tune the excitation spectra in visible wavelength and emission spectra above 600 nm with a large Stokes shift in the range of 3632-5058 cm-1. Moreover, this modification provides a great platform for numerous noncovalent interactions, which significantly enhance aggregation- and solid-state fluorescence properties. Furthermore, various experimental, spectroscopic, and theoretical studies and X-ray crystallography measurements elucidate the structure-property relationships of these molecules, which pave the way for the development of novel materials with various applications in sensing and bioimaging. As a proof of concept, the potential of these molecules has been successfully demonstrated for the development of vapor- and solution-phase dynamic acid-base stimuli-responsive smart sensors, as well as the application of the BTz molecule in live-cell imaging.

Exploiting Activated Alkyne Chemistry for the Synthesis of Tailored Amphiphilic Janus Dendrimers with Aggregation-Induced Emission and Their Assemblies for Cell Imaging

Amphiphilic Janus dendrimers (AJDs) are a promising class of macromolecules capable of self-assembling into well-defined nanostructures. In this study, AJDs were synthesized employing, for the first time, the activated alkyne-hydroxyl "click" chemistry approach, enabling the construction of dendritic architectures under mild conditions. The AJDs were functionalized with a π-extended tetraphenylethylene (TPE) derivative, imparting aggregation-induced emission (AIE) property. These AJDs self-assembled into fluorescent nanostructures, including micelles and dendrimersomes, with tunable dimensions. The AIE-active assemblies demonstrated strong photoluminescence upon formation and were characterized by narrow size distributions. Cytotoxicity and cellular uptake studies using Chinese Hamster Ovary K1 (CHO-K1) cells revealed excellent biocompatibility and efficient cellular internalization, confirming their potential for live-cell imaging. Importantly, the extended π-conjugation of the TPE derivative facilitated excitation at longer wavelengths, compatible with conventional confocal microscopy. This work showcases the versatility of activated alkyne-hydroxyl "click" chemistry in dendrimer synthesis and highlights the potential of these AJD-based nanostructures in nanomedicine, particularly for imaging and diagnostic applications.

Fluorescent Chemosensors in the Detection of Ultra-trace Quantity of Toxic Hg2+, Pb2+, Al3+, F-, AsO43- & AsO33- in Water Towards Better Health Management-A Comprehensive Review

Chemosensors have extensive applications in chemical, biological and environmental sciences. Fluorescent chemosensors are the most powerful techniques for rapid detection of ultra-trace quantity of inorganic ions in water samples with high sensitivity. Water is contaminated with various pollutant ions e.g., Cd2+ Cu2+, Hg2+, Pb2+, Mn2+, Zn2+, Al3+, AsO43-, AsO33- and F- due to increase industrialisation, usage of fertilizers, through food -beverages, water purification instruments and e-wastes. Thus, contaminated water is a potential threat to life as it transmits various bacterial waterborne diseases, so detection of contaminants is essential. This review focuses the recently developed single, dual and multi-analyte fluorescent chemosensors ligands for the detection through selective binding of trace quantity of critically toxic ions e.g., Hg2+, Pb2+ Al3+, F-, AsO33- and AsO43- in water and food samples. Binding of ions through Sensing mechanism: Intramolecular Charge transfer (ICT), Foster Resonance energy transfer (FRET), Aggregation based approaches, Photo induced electron transfer (PET) etc. have also discussed. Ligands i) derivatives of rhodamine dyes and phenanthroline ii) Schiff base with rhodamine B thiohydrazide and quinoline moiety iii) a chromone-quinolinyl hydrazide Schiff base as dual sensors iv) Nitro-furaldehyde based Schiff base as multi-analyte sensors having potential doner atoms to bind the concerned ions and easily synthesizable have been selected for reviews. The detections of toxic ions were accomplished by spectroscopic studies. Such comprehensive review has not yet been reported. This review emphasizes the works of pioneering researchers on chemosensors during the period 1990-2025. This review will also help future researchers to design new Schiff bases chemosensor and its selectivity for the detection of trace quantity of hazardous ions from environment and biological samples thereby monitoring human health.

Zinc(II)-Enhanced Excimer Probe for Recognition of MDMB-CA Synthetic Cannabinoids

Specific recognition with optical responses towards the analytes which are structurally diverse and weak chemical-active remains a big challenge but is of great significance. Here, a zinc(II) enhanced fluorescent emission probe was developed by conjugated modulating and metal bridging to specifically recognize synthetic cannabinoids (SCs). The transformed luminescence mechanism from excimer emission to fluorescence resonance energy transfer was demonstrated upon the integration of coordination and non-covalent interactions towards target SCs. As a result, the specific and instant detection of the certain type SCs (MDMB-CA series) was achieved in complicated sample medium. Hence, we envisage that this work would not only offer a novel recognition strategy for SCs, but also advance the development of the optical sensing probe especially for analyzing the substances with diverse structures and weak chemical-activity, as well as for fighting against the illicit drugs.

Dimethylacridine Based Emitters for Non-Doped Organic Light-Emitting Diodes with Improved Efficiency

Organic light-emitting diodes (OLEDs) has been attracting much extensive interest owing to their advantages of high-definition and flexible displays. Many advances have been focused on boosting the efficiency and stability. Two innovative dimethylacridine-based emitters, 1,1,2,2-tetrakis(4- (2,7-di-tert-butyl-9,9-dimethylacridin-10(9H)-yl)phenyl ethene (AcTPE), and bis(4-(2,7-di-tert-butyl-9,9-dimethylacridin-10(9H)-yl)phenyl)methanone (Ac2BP) were designed and synthesized, in which TPE-baesed AcTPE presents AIE properties, and with the phenyl as spacer between the DMAC and carbony, aryl-ketone-based Ac2BP doesn't show AIE properties due to the absence of restriction of intramolecular rotations. As the electron-withdrawing ability of carbonyl, well-matched energy levels of the Ac2BP improve carriers transfer and hole injecting process in devices, resulting an efficient green emission with a maximum PE of of 5.64 lm W-1, a EQE of 10.56 % and a maximum CE of 18.27 cd A-1. They are much higher than that of AcTPE-based devices (3.45 cd A-1, 1.18 lm W-1, and 1.46 %). This study provides a promising design strategy for efficient OLED emitters of aryl-ketone-architecture.

Metal Organic Framework Based on Photoactivated Aggregation-Induced Emission Molecule for Achieving Photoexcitation Regulation

Ln-MOFs, composed of lanthanide ions and functional organic ligands, are porous materials with tunable structures and unique luminescent properties. However, the interplay between ligand AIE properties and the framework's "antenna effect" on MOF morphology is understudied. Here, Tb-D-Cam-TPTB was synthesized via solvothermal method using TPTB (persulfurated arene) as the primary ligand, D-Cam as the auxiliary ligand, and Tb3+ as the metal ion. Photoexcitation of TPTB, a typical AIE molecule, promotes conformational changes, enhancing molecular aggregation and luminescence. Comprehensive photophysical investigations of TPTB in solution and crystal states, Tb3+-TPTB coordination, and Tb-D-Cam-TPTB MOF were conducted using various spectroscopic and imaging techniques. This study explores the interaction between ligand AIE and the "antenna effect" on Ln-MOF luminescence and crystal structure. The results indicate that, when the ligand is a photoexcitation-induced AIE molecule, UV irradiation of the precursor solution prior to crystal growth can alter the crystal structure, luminescence intensity, and color, holding great promise for applications in anti-counterfeiting, sensing, and other related fields.

Theoretical Insights into the Impact of the Central Atom on the Photoluminescence Mechanisms of Ligand-Protected Cu Nanoclusters

Ligand-protected copper nanoclusters (CuNCs) have attracted considerable attention in both fundamental research and practical applications due to their easy availability, environmental friendliness, and exceptional optical properties. In this study, density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations were employed to investigate the photoluminescence (PL) mechanism of two-electron (2e) cluster [Au@Cu14(SCH2CH3)12(P(CH2CH3)3)6]+ (Au@Cu14) and zero-electron (0e) cluster [Cl@Cu14(SCH2CH3)12(P(CH2CH3)3)6]+ (Cl@Cu14) to explore the impact of the central atom on the PL mechanisms of CuNCs. The accuracy of various exchange-correlation (XC) functionals used for fluorescence and phosphorescence energy calculations was evaluated. The BP86 and PBE0 functionals were used to calculate the radiative and nonradiative transition processes of the two clusters. Theoretical calculations showed that enhanced spin-orbit coupling, larger transition dipole moments, more significant orbital overlap, and smaller Huang-Rhys factors and reorganization energies were the main reasons for the higher PL quantum yield (PLQY) of Au@Cu14 than Cl@Cu14. These findings provide important insights into the central atom effect of CuNCs and valuable guidance for their design and optimization in optical applications.

Multiscale Structural Analysis of Aggregation-Induced Emission Nanocrystals by Combining Electron and Confocal Microscopy

Aggregation-induced emission (AIE) materials have attracted intense interest due to their remarkable luminescent properties and potential applications in biological and medical fields. A comprehensive structural analysis from atomic-level to micrometer-scale is essential for rationally designing AIE materials and understanding their structure-property relationships. However, this remains a challenge due to the lack of proper methods. Herein, we present a strategy for multiscale structural analysis of AIE materials through a combination of electron and confocal microscopy. One mechanically induced fluorescent AIE material consisting of a chiral Au(I) complex was prepared and studied. The correlation of scanning electron and optical microscope images reveals that the fluorescence is closely related to the anisotropy of nanocrystals with strong signals on fracture {110} facets. Furthermore, instead of growing large single crystals, atomic-level crystal structures of individual nanocrystals were directly resolved using three-dimensional electron diffraction (3D ED), highlighting the changes in molecular arrangement before and after mechanical treatment. The results provide experimental evidence for the previously proposed mechanically induced Restriction of Intramolecular Rotation (RIR) mechanism.

Recent Advances in Aggregation-Induced Emission Bioconjugates

Fluorescence imaging technology is playing increasing roles in modern personalized and precision medicine. Thanks to their excellent photophysical properties, organic luminogens featuring aggregation-induced emission (AIE) characteristics (AIEgens) have attracted considerable attention over the past two decades. Because of their superior biocompatibility, ease of processing and functionalization, excellent water solubility, high responsiveness, and exceptional signal-to-noise ratio (SNR) for biotargets, AIE bioconjugates, formed by covalently linking AIEgens with biomolecules, have emerged as an ideal candidate for bioapplications. In this review, we summarize the progress in preparation, properties, and application of AIE bioconjugates in the last five years. Moreover, the challenges and opportunities of AIE bioconjugates are also briefly discussed.

Glutathione: a naturally occurring tripeptide for functional metal nanomaterials

Glutathione (GSH), a naturally occurring tripeptide, plays an important role as an intracellular antioxidant in the physiological microenvironment and participates in redox balance, detoxification, and cellular and disease regulation. The unique structural features of GSH, including the reductive thiol and multiple coordination sites (carboxyl and amino group), make it a significant molecule not only in the physiological context but also as a ligand in the development of functional metal nanomaterials. In this context, GSH's role as a protective ligand and reducing agent in surface etching and ligand exchange reactions has been explored at the molecular level, expanding the diversity of GSH-protected metal nanomaterials. With photoluminescence (PL) as one of its most intriguing properties, investigations into GSH's influence on PL properties emphasize its multifaceted coordination capabilities in surface coating, charge transfer from electron-rich functional groups, chirality arising from its unique structure, and available conjugation sites. Moreover, the biocompatibility of GSH, combined with the synergistic effect of metal components, renders GSH-protected nanomaterials an "Inseparable Duo" highly suited for applications in bio-sensing, bio-imaging via PL radiative decay and anti-cancer bio-therapies through photothermal therapy, photodynamic therapy, and radiotherapy. By exploring the multifaceted roles of GSH, this Perspective aims to highlight pathways including the encouragement of deeper synthetic exploration, innovative design at the bio-nano interface, and expanded nanobiomedical applications.

Algorithm in chemistry: molecular logic gate-based data protection

Data security is crucial for safeguarding the integrity, authenticity, and confidentiality of documents, currency, merchant labels, and other paper-based assets, which sequentially has a profound impact on personal privacy and even national security. High-security-level logic data protection paradigms are typically limited to software (digital circuits) and rarely applied to physical devices using stimuli-responsive materials (SRMs). The main reason is that most SRMs lack programmable and controllable switching behaviors. Traditional SRMs usually produce static, singular, and highly predictable signals in response to stimuli, restricting them to simple "BUFFER" or "INVERT" logic operations with a low security level. However, recent advancements in SRMs have collectively enabled dynamic, multidimensional, and less predictable output signals under external stimuli. This breakthrough paves the way for sophisticated encryption and anti-counterfeiting hardware based on SRMs with complicated logic operations and algorithms. This review focuses on SRM-based data protection, emphasizing the integration of intricate logic and algorithms in SRM-constructed hardware, rather than chemical or material structural evolutions. It also discusses current challenges and explores the future directions of the field-such as combining SRMs with artificial intelligence (AI). This review fills a gap in the existing literature and represents a pioneering step into the uncharted territory of SRM-based encryption and anti-counterfeiting technologies.

Zinc Sulfate Open Frameworks with Nonconventional Room-Temperature Phosphorescence for Selective Amine Vapor Detection

Molecular-based afterglow materials have garnered significant attention due to their diverse applications. However, most studies focus on conventional luminophores, leaving nonconventional systems underexplored, particularly regarding the screening of new material subclasses and the development of applications such as sensing. Herein we report the successful preparation of two new two-dimensional ZnSO4-based open-framework materials (OFMs)─(H2DABCO)[Zn3(μ3-OH)2(SO4)3]·H2O (1) and (H2DABCO)[Zn(SO4)2] (2)─through self-assembly of Zn2+/SO42- with nonaromatic triethylenediamine (DABCO). Both compounds exhibit distinct delayed emission characteristics with lifetimes of 259.10 ms (1) and 49.62 μs (2), respectively. Frontier orbital analysis reveals the key role of charge transfer between sulfate groups to (H2DABCO)2+ cations in the luminescence. Notably, 1 demonstrates exceptional performance as an afterglow probe for the selective detection of n-propylamine and n-butylamine vapors, achieving detection limits of 32.99 and 47.18 ppm, respectively. The sensing mechanism involves a phase-transition process, and the luminescence change can be observed by the naked eye. This work pioneers the integration of sulfate-based OFMs with nonconventional room-temperature phosphorescence properties, demonstrating their potential as afterglow probes for industrial and environmental monitoring.

Amphiphilic Styrene-Based Pyrene Derivatives: Tunable Aggregation Luminescence and Their Photo-Induced Dimerization Behavior

Since the discovery of the aggregation-induced emission (AIE) phenomenon, various stimuli-responsive materials have been rapidly developed. However, how to achieve the transition between aggregation-caused quenching (ACQ) and AIE through molecular design is an urgent problem to be solved. In this work, we synthesized and studied the aggregation luminescence behavior and photochromism of two different substituted pyrene ethylene derivatives, 1-H and 1-CN. Due to the different substituents attached to the ethylene unit, 1-H exhibits ACQ luminescence behavior. When the substituent is a cyanide group, it exhibits AIE behavior. In addition, the ordered nanoparticles formed by self-assembly in aqueous solution exhibit interesting photo-induced cyclization behavior, which leads to fluorescence quenching under ultraviolet light irradiation (λ = 365 nm). Therefore, due to their amphiphilicity and photo-responsiveness, these compounds can be used as anticounterfeiting inks in information encryption. This work contributes new members to the family of amphiphilic photo-responsive materials and demonstrates their potential applications in optical information storage and multi-color luminescence.

Design, Synthesis, and Evaluation of Boron Dipyrromethene-Based Fluorescent Probes Targeting BRAF for Melanoma Diagnosis

Fluorescent dyes are widely applied in clinical diagnosis, detection, and treatment of diseases. Several image probes such as ICG, MB, and 5-ALA have been approved by FDA. However, the limited tumor-targeting capability of these dyes hinders their effectiveness in oncological imaging. Currently, various ligand-based targeting probes have been developed to minimize nonspecific background emission. BRAF, especially BRAF V600E, is a common cancer gene and undergoes frequent mutation in melanoma. Small molecular BRAF kinase inhibitors have been approved for the treatment of melanoma patients carrying the BRAF V600E mutation, including Vemurafenib, Dabrafenib and so on. Boron dipyrromethene (BODIPY) as an important fluorescent class has been investigated extensively. Vemurafenib-BODIPY has been reported to visualize BRAF V600E mutated cancer cells. Herein, the designed BODIPY-based Vemurafenib derivatives targeting BRAF for cancer cell imaging are reported. The fluorescent probes are characterized and evaluated of photophysical properties, targeted binding and live cell imaging. Compound 1a exhibited promising fluorescence imaging ability. To improve fluorescence quantum yield, structural optimization is performed by incorporating meso N,N'-dialkyl-substituted amides to BODIPY core. Compound 1d shows excellent fluorescence properties and nice binding affinity. It allows visualization of BRAF V600E mutated cancer cells at low concentrations.

Confined Structural Water Molecules as Alternative Potential Emitters for Bright Photoluminescence of Thiolate-Gold Complexes

The debate about water as an emitter has spanned nearly a century, but how it emits bright colors remains elusive. In this report, using the widely used Au(I)-alkanethiolate complex (Au(I)-SRs, R=-(CH2)12H) with AIE properties as a model system, by carefully manipulating the delicate surface-ligand interactions at the nanoscale interface, together with a careful spectral investigation and an isotopic diagnostic experiment of heavy water (D2O), we demonstrated that the structural water molecules (SWs) trapped in the nanoscale interface or space are the true emission centers of metal nanoclusters (NCs) and the aggregates of Au(I)-SRs complexes, instead of a well-organized metal core dominated by quantum confinement mechanics. Unlike conventional hydrogen-bonded water molecules, due to interfacial adsorption or spatial confinement, the p-orbitals of two O atoms in SWs can form strong electronic interactions through spatial overlap, thus constructing a set of interfacial states, one of which is characterized by π-bonding, thus providing alternative channels (or paths) for the relaxation decay of the excited electrons. Using the one-dimensional free-electron gas model, the energy levels calculated by the Schrödinger equation are in perfect agreement with the experimental observations, further validating the SWs model.

Activatable Photosensitizers: From Fundamental Principles to Advanced Designs

Photodynamic therapy (PDT) is a promising treatment that uses light to excite photosensitizers in target tissue, producing reactive oxygen species and localized cell death. It is recognized as a minimally invasive, clinically approved cancer therapy with additional preclinical applications in arthritis, atherosclerosis, and infection control. A hallmark of ideal PDT is delivering disease-specific cytotoxicity while sparing healthy tissue. However, conventional photosensitizers often suffer from non-specific photoactivation, causing off-target toxicity. Activatable photosensitizers (aPS) have emerged as more precise alternatives, offering controlled activation. Unlike traditional photosensitizers, they remain inert and photoinactive during circulation and off-target accumulation, minimizing collateral damage. These photosensitizers are designed to "turn on" in response to disease-specific biostimuli, enhancing therapeutic selectivity and reducing off-target effects. This review explores the principles of aPS, including quenching mechanisms stemming from activatable fluorescent probes and applied to activatable photosensitizers (RET, PeT, ICT, ACQ, AIE), as well as pathological biostimuli (pH, enzymes, redox conditions, cellular internalization), and bioresponsive constructs enabling quenching and activation. We also provide a critical assessment of unresolved challenges in aPS development, including limitations in targeting precision, selectivity under real-world conditions, and potential solutions to persistent issues (dual-lock, targeting moieties, biorthogonal chemistry and artificial receptors). Additionally, it provides an in-depth discussion of essential research design considerations needed to develop translationally relevant aPS with improved therapeutic outcomes and specificity.

High-Efficiency Light Emitters: 10-(Diphenylphosphoryl)-anthracenes from One-Pot Synthesis Including C-O-P to C-P(═O) Rearrangement

We report a one-pot synthesis of 10-(diphenylphosphoryl)-anthracenes, featuring a rare multisubstitution on flanking rings with donor-acceptor groups (F, Br, CN, CF3, MeO, OCH2O) in 24-60% yields. Catalyzed by TMSOTf, the process involves a phosphinite-to-phosphine oxide rearrangement and cyclization. These emitters exhibit excellent photoluminescence quantum yields of up to 95% in both solution and solid states. Postsynthetic anthracene functionalization as well as the optoelectronic effect of substituents, particularly the Ph2P═O group, and the aggregation effect in solid on the photophysical properties, were also explored.

Copillar[5]arene Appended Pyrene Schiff Base: Photophysics, Aggregation Induced Emission and Picric Acid Recognition

Herein, we report the synthesis of copillar[5]arene-based pyrene Schiff base 1 and its characterization by using 1H, 13C NMR, FT-IR and mass spectrometry. UV-vis absorption, steady-state fluorescence and time-resolved fluorescence are done to elucidate the photophysical behaviors of 1. To understand the electronic structure of 1, density functional theory (DFT) calculations are performed. Owing to the presence of pyrene via a Schiff base linkage, compound 1 exhibits aggregation-induced emission (AIE) characteristics. It shows aggregation in aqueous THF and DMF. The aggregation behavior is successfully demonstrated by steady-state fluorescence, dynamic light scattering (DLS) and time-correlated single-photon counting (TCSPC) experiments. Experimental findings reveal that hydrophobic effect is the driving force in the formation of aggregates. As application, the aggregated state of 1 in aqueous THF fluorimetrically recognizes picric acid (PA) selectively over a series of nitro- and nonnitroaromatics with a detection limit of 1.62×10-7 M. The emission of the aggregated state is fully quenched upon interaction with PA.

Artificial light harvesting systems based on novel AIEgen-branched rotaxane dendrimers for photocatalyzed functionalization of C-H bonds

Aiming at the construction of novel luminescent materials for practical use, a new type of AIEgen-branched rotaxane dendrimer with up to 42 TPE units precisely distributed with dendrimer skeletons was successfully synthesized. Attributed to such high-density topological arrangements of AIEgens, these novel rotaxane-branched dendrimers revealed interesting generation-dependent AIE behaviors. Moreover, taking advantage of the efficient Förster resonance energy transfer (FRET) process, novel artificial light-harvesting systems (LHSs) were successfully constructed by the employment of ESY as energy acceptors, which revealed significantly enhanced photocatalytic performances in the functionalization of C-H bonds along with an increase in dendrimer generation, thus indicating an impressive generation effect.

Luminescent ultrashort peptide hydrogelator with enhanced photophysical implications and biocompatibility

Luminescent peptide hydrogelators have garnered significant attention in biomedical sciences and materials chemistry due to their biological relevance and tunable photophysical features. In this work, we have designed and synthesized a novel ultrashort peptide hydrogelator comprising a tripeptide sequence (FFE) integrated with 1,8-naphthalimide (NI) as an aggregation-induced emissive unit having rich and tuneable photophysical properties. The hydrogelator could self-assemble and form a self-supporting hydrogel having a highly ordered intertwined network structure at pH 5.5 with a minimum gelation concentration of 1 wt/v%. Interestingly, due to the presence of the emissive unit, the assembly could demonstrate strong blue luminescence, which has been thoroughly investigated experimentally. Moreover, spectroscopic investigations and molecular dynamics simulation studies suggest the formation of a β-sheet structure through extended intermolecular H-bonding interactions within the peptide backbones and the strong π-π-stacking interaction among aromatic units, which drive the self-assembly and hydrogelation. The emissive unit of the peptide could arrange in a J-type aggregation pattern and adopt right-handed helical induced chirality in the assembled state. Additionally, the system could exhibit a high safety profile and excellent biocompatibility, when tested in a series of cell lines in vitro. Finally, the intracellular uptake of the system has been exploited, showcasing its luminescence characteristics for potential applications in cellular imaging. The luminescent system holds significant promise for advancing cellular imaging techniques, offering new avenues for research in the future. Briefly, this work highlights the importance of luminescent ultrashort peptide hydrogelators for developing next-generation low-cost functional biomaterials.

Research Progress on Antibacterial Applications of Bioactive Materials in Wound Infections: Design, Challenges, and Prospects

Bacterial wound infections pose a significant threat to global health, exacerbated by the increase in multidrug-resistant bacteria (MDRB) and the formation of elastic biofilms. This review explores the transformative potential of bioactive materials in addressing these challenges, focusing on their design, mechanisms of action, and therapeutic effects. In vivo, bioactive materials are designed to respond to unique bacterial microenvironment (BME), utilizing enzyme activity, controlled gas release, surface functionalization, and immune regulation to combat infections. In vitro, this review provides a comprehensive overview of the latest advances in the rational design of these materials, emphasizing the synergistic integration of structural modifications (such as size and morphology) with external physical stimuli (such as light, sound, electricity, magnetism, and force) to enhance antibacterial performance. Finally, the outstanding challenges and prospects in this rapidly evolving field are discussed.

Bovine serum albumin framed activatable NIR AIE photosensitizer for targeted tumor therapy

Organic near-infrared (NIR) photosensitizers (PS) largely facilitate photodynamic therapy (PDT). To overcome aggregation induced quenching and diminishment of reactive oxygen species (ROS) generation capability of NIR-PS, aggregation-induced emission (AIE) effect groups have been introduced to generate NIR AIE photosensitizers. However, currently reported NIR AIE photosensitizers all take "always-on" activity that may cause systemic phototoxic side effects. Tumor microenvironment activatable NIR AIE photosensitizers have not been reported. Here we develop an activatable NIR AIE PSnanoparticle (a-NA-PSNP) for near-infrared-II (NIR-II) fluorescence (FL) imaging-guided PDT under 808 nm excitation. NIR AIE photosensitizer (N-PS) is designed and frames with cysteine (Cys)/glutathione (GSH) responsive charge transfer complex (CTC) in bovine serum albumin (BSA) to obtain a-NA-PSNP. With the aggregated state in BSA, N-PS shows high quantum yield with good photostability. As an energy acceptor, CTC quenchs NIR-II fluorescence and ROS production capability of a-NA-PSNP in normal cells and tissues. CTC is decomposed in response to tumor microenvironment Cys/GSH, therefore recovers NIR-II fluorescence of a-NA-PSNP and efficiently generates ROS under 808 nm light irradiation. The depletion of Cys/GSH also regulates tumor intracellular reductive environment to further facilitate PDT. Both in vitro and in vivo results confirmed the tumor microenvironment selective and efficient activation of a-NA-PSNP, indicating its potential in cancer therapy.

H2O2-Driven Aggregation Induced Emission-Based Nanomotors for the Monitoring and Treatment of Infected Surgical Wound

Post-operative surgical wound monitoring remains a significant clinical challenge in preventing bacterial infection. Current methods rely on indirect observations or costly investigations, often detecting infections only after complications arise. Here the medical sutures coated with Janus-type nanomotors (Pt-MOFs) with infected microenvironment-responsive properties for monitoring and treating surgical site infections are prepared. The Pt-MOFs nanomotors exhibit efficient self-propulsion with enhanced penetration and diffusion in biofilms by catalyzing hydrogen peroxide to produce oxygen bubbles. Copper ions serve dual roles as structural nodes and Fenton-like catalysts, generating antibacterial hydroxyl radicals while forming non-emissive self-aggregates. Here in vitro is shown that Pt-MOFs nanomotors present excellent bacterial imaging and enhanced antibacterial activity against both Gram-positive and Gram-negative bacteria. As a proof of concept, Pt-MOFs nanomotors coated surgical sutures successfully monitor the process of Staphylococcus aureus-infected wounds on mouse model. Furthermore, in vivo studies testify that Pt-MOFs nanomotors play an important role in treating infected surgical wounds through mitigating inflammatory infiltrates, facilitating collagen deposition and accelerating reepithelialization. This combined monitoring and treatment approach offers a promising strategy for surgical wound healing.

An AIEE-active Triphenylethylene Derivative with Photoresponsive Character for Latent Fingerprints Detection via a Simple Soaking Method

Latent fingerprints (LFPs) is one of the most important physical evidence in the criminal scene, playing an important role in forensic investigations. Therefore, developing highly sensitive and convenient materials for the visualization of LFPs is of great significance. We designed and synthesized an organic fluorescent molecule TP-PH with aggregation-induced enhanced emission (AIEE) activity. By simply soaking, blue fluorescent images with high contrast and resolution are readily developed on various surfaces including tinfoil, steel, glass and plastic. Remarkably, LFPs can be visualized within 5 min including the first-, second- and tertiary-level details. In addition, TP-PH exhibits interesting photoactivated fluorescence enhancement properties. Under irradiation of 365 nm UV light with a power density of 382 mW/cm2, the fluorescence quantum yield displays approximately 21.5-fold enhancement. Mechanism studies reveals that the photoactivated fluorescence is attributed to the irreversible cyclodehydrogenation reactions under UV irradiation. This work provides a guideline for the design of multifunctional AIEE fluorescent materials.

Bis-Naphthylacrylonitrile-Based Supramolecular Artificial Light-Harvesting System for White Light Emission

A novel aggregation-induced emission (AIE)-based artificial light-harvesting system (LHS) is successfully assembled via the host-guest interaction of bis-naphthylacrylonitrile derivative (BND), water-soluble pillar[5]arene (WP5), and sulforhodamine 101 (SR101). After host-guest assembly, the formed WP5⊃BND complexes spontaneously self-aggregated into WP5⊃BND nanoparticles (donors) and SR101 (acceptors) is introduced into WP5⊃BND to fabricate WP5⊃BND-SR101 LHS. Through the investigation of energy transfer between donors and acceptors, the artificial light-harvesting processes are certified in WP5⊃BND-SR101 LHS and the absolute fluorescence quantum yields (Φf(abs)) are significantly improved from 8.9% (for WP5⊃BND) to 31.1% (for WP5⊃BND-SR101), exhibiting the excellent light-harvesting capabilities. Notably, by tuning the donor/acceptor (D:A) molar ratio to 250:1, a conspicuous white light emission (CIE coordinate is (0.32, 0.32)) is realized and the fluorescence quantum yield of white light emission (Φf(abs) WP5 ⊃ BND-SR101-White) is 29.2%. Moreover, the antenna effect of white fluorescence emission (AEWP5 ⊃ BND-SR101-White) can reach 36.2, which is higher than that of recent artificial LHSs in water environments, suggesting vast potential applications in aqueous LHSs.

Abnormal Slow Phonon Dynamics Toward Prolonging Excited States Dynamics Enabled by Crystalline-Assembling Donor-Acceptor Molecules

Phonon dynamics are a critical factor to control the optical properties of excited states in light-emitting materials. Here, we report an extremely slow relaxation of photoexcited lattice vibrations enabled by assembling the donor-acceptor (D-A) molecules [2-(9,9-dimethylacridin-10(9H)-yl)-9,9-dimethyl-9H-thioxanthene 10,10-dioxide], namely AC molecules, into dipolar crystal. By using photoexcitation-modulated Raman spectroscopy, we find that the crystalline-lattice vibrations monitored by Raman-scattering laser beam of 785 nm demonstrate an un-usual slow relaxation in the time scale of seconds after ceasing photoexcitation beam of 343 nm in such dipolar crystal. This presents extremely slow phonon dynamics enabled by crystalline-assembling the D-A molecules into a dipolar crystal. Simultaneously, the photoluminescence (PL) exhibits a prolonged behavior, lasting 10 ms after ceasing photoexcitation in dipolar AC crystal. This phenomenon provides an experimental hypothesis that the slow phonon dynamics function as an important mechanism to unusually prolong excited states dynamics upon crystalline-assembling the D-A molecules into dipolar crystal. This hypothesis can be verified by directly suppressing the phonon dynamics through freezing D-A molecular liquid into dipolar crystalline solid at 77 K to largely prolong the PL to 1 s- after removing photoexcitation. Clearly, crystalline-assembling D-A molecules provide the necessary conditions to enable slow phonon dynamics toward prolonging excited states dynamics.

Flower-like tailored carbon nitride oligomer as an excellent aggregation-induced electrochemiluminescence emitter for sensitive immunoassay of neuron-specific enolase via dual quenching by bimetallic phenolic networks

The adjustment of the electrochemiluminescence (ECL) of polymeric carbon nitride (C3N4) is essential for its application in sensitive immunoassays. However, such modification through aggregation-induced emission (AIE) has not yet been reported. Herein, aggregation-induced ECL in C3N4 oligomer (CNO) was induced through the introduction of a rotatable imine moiety, with the resulting material exhibiting excellent performance in the targeted immunodetection of neuron-specific enolase. Phenyl-modified CNO was synthesized through one-step pyrolysis at a reduced temperature. The rotatable benzene ring and triazine group formed a dynamic structure, which exhibited strong aggregation in water-doped solvents. compared to unmodified graphitic C3N4, CNO demonstrated higher intrinsic ECL efficiency and more readily accessible ECL signals. AIE inducing polymerization was conducted via nanoprecipitation, and the resulting CNO micro-flowers were employed as a sensing platform. A CNO-based sensor was prepared by combining CNO micro-flowers with copper-based bimetallic phenolic network nanoparticles as a quencher. Sensitive signal quenching was achieved owing to the electron transfer of Cu2+ and antioxidation properties of polyphenolic structures. The prepared sandwich-type immunosensor for neuron-specific enolase showed a limit of detection of 0.12 pg/mL in the detection range of 0.001-100 ng/mL. This study presents an effective strategy for the ECL signal amplification of C3N4, which is conducive to fundamental research in ECL and the application of the proposed sensor in the early diagnosis of diseases.

A mitochondrial targeted fluorescent probe for imaging nitroreductase activity and photodynamic therapy in tumor cells

The hypoxic environment in tumors is closely linked to tumor structure, function, dissemination, invasion, metastasis, and drug resistance. Nitroreductase (NTR) is often recognized as a biomarker to evaluate the hypoxia degree for tumor cells. Traditional detection methods such as PET, MRI and multispectral photoacoustic tomography have limitations. Fluorescent probes have garnered attention due to their high sensitivity, rapid response, specificity, and non-invasive nature. In this study, we introduced a novel small molecule fluorescent probe, T-TPE-NO2, designed with an AIE molecular framework TPE and successfully targeted to the mitochondria of tumor cells. The probe had high selectivity and could detect NTR activity in a broad pH range. Additionally, the probe exhibits high sensitivity with a LOD of 46.3 ng/mL. Under tumor NTR, the probe emitted strong fluorescence signals and generated a substantial amount of reactive oxygen species upon laser irradiation, thereby inducing tumor cell death and enabling photodynamic therapy. The synthesis, structural and morphological characterization of the probe were rigorously validated. Experimental results demonstrate that T-TPE-NO2 exhibited high sensitivity and selectivity for tumor cells, highlighting its potential application in photodynamic therapy. This research offers a new approach for the detection and treatment of tumor hypoxia.

Surface-modified carbon quantum dot for enhanced fluorescent-sensing of hexagonal valent chromium

As one of the most harmful heavy metal pollutants, hexavalent chromium Cr(VI) is becoming a serious threat to human health. Thus pursuing a remarkably sensitive method to monitor the Cr(VI) concentration in natural conditions is favored for the fast response to prevent harm. In the present work, an ethylenediamine (En) and SiO2-modified wool keratin-based carbon quantum dot (CQD)(En@CQDs@SiO2) fluorescent sensor is prepared, and the En is found to improve the discrimination ability by binding the Cr(VI) with the surface carboxyl groups. Based on these designs, the En@CQDs@SiO2 achieves a significant improvement in the Cr(VI) detection ability, with a detection limit of 6.08 × 10-4 mg/L, which succeeded 6 times over CQDs, and is better than conventional UV-Vis and flame atomic absorption (AAS) techniques. Furthermore, the fluorescent sensor has good relative sensitivity, selectivity, good spectral reproducibility, and excellent structural stability. These properties make the sensor suitable for environmental Cr(VI) detection, which undoubtedly improves the economy and environmental friendliness of the fluorescent sensor.

Frontier in Advanced Luminescent Biomass Nanocomposites for Surface Anticounterfeiting

Biomass-based luminescent nanocomposites have garnered significant attention due to their renewable, biocompatible, and environmentally sustainable characteristics for ensuring information encryption and security. Nanomaterials are central to this development, as their high surface area, tunable optical properties, and nanoscale structural advantages enable enhanced luminescent efficiency, stability, and adaptability in diverse conditions. This review delves into the principles of luminescence, focusing on the inherent bioluminescent properties of natural materials, the utilization of biomass as precursors for carbon dots (CDs) and aggregation-induced emission (AIE)-enhanced substances, and the structural and functional optimization of luminescent materials. The role of cellulose nanocrystals (CNC), lignin, and chitosan as key biomass-derived nanomaterials will be highlighted, alongside surface and interfacial engineering strategies that further improve material performance. Recent advancements in the synthesis of biomass carbon dots and their integration into luminescent anticounterfeiting systems are discussed in detail. Furthermore, the integration of advanced artificial intelligence (AI) technologies is explored, emphasizing their potential to revolutionize luminescent anticounterfeiting. Current challenges, including scalability, waste minimization, and performance optimization, are critically examined. Finally, the review outlines future research directions, including the application of AI-driven methodologies and the exploration of unconventional luminescent biomass materials, to accelerate the development of high-performance, eco-friendly anticounterfeiting solutions.

Quadrupling the PLQY of Tetraphenylethylene by Covalently Linking it with Isosteric Tetraarylaminoborane: A Potential Candidate for Multicolor Live Cell Imaging

Applications of organic luminophores depend on their photoluminescence quantum yield (PLQY). Several strategies have been developed to improve the PLQY of organic solids, and one such method is aggregation-induced emission (AIE). Herein, we disclose a comprehensive study of two molecularly engineered covalently linked isosteric AIEgens, BNTPE-1 and BNTPE-2. The independent isosteres tetraarylaminoborane (BN) and tetraphenylethylene (TPE) showed poor PLQY; however, the covalently linked BNTPE-1 and BNTPE-2 systems showed 4 times higher PLQY than the independent isosteres (∼78 and ∼92% for solids and aggregates, respectively). Detailed optical, structural, and computational studies revealed that BN and TPE moieties adopt more coplanarity and have stronger donor (-NPh2)-acceptor (BMes2) interactions in the covalently linked systems than do simple BN and TPE units. Despite having sterically demanding BMes2 units, these compounds are nonemissive in the solution state due to the presence of flexible TPE units. However, they are strongly emissive in condensed states, such as aggregates in solution and the solid state. The excited state structure analysis revealed that the TPE unit undergoes severe conformational distortion after photoexcitation, which activates nonradiative decay channels and consequently quenches the luminescence in the molecularly dispersed state. The bioimaging potential of BNTPE-1 and BNTPE-2 was also explored. These compounds showed high biocompatibility and stained the HeLa cells brighter than BN and TPE molecules.

TBP-based AIE Fluorescent Probe for Cysteine/Homocysteine Detection and Imaging in Living Cells

The abnormality expression of biothiols in organisms may give rise to a number of pathological conditions. Therefore, the accurate detection of biothiols is of significant importance for the diagnosis of diseases associated with their aberrant levels. In this paper, we designed a small molecule fluorescent probe with good AIE performance to specifically detect Cys/Hcy, which makes up for the limitation of probes with aggregation-induced quenching effect. The probe was synthesized by coupling 7-nitro-1,2,3-benzenediazole (NBD) as a recognition group to the fluorophore TBP, which has obvious aggregation-induced emission effect (AIE). The Cys/Hcy thiol functional group cut off the ether bond of TBP-NBD, NBD-Cys/Hcy with strong fluorescence was generated, results in a 50 ~ 100 folds increase in fluorescence intensity indicating the fluorescence was turned on. However, the fluorescence intensity was not significantly enhanced after co-incubation with GSH, which could achieve a good distinction between Cys/Hcy and GSH. In this paper, a series of experiments show that TBP-NBD has good Cys/Hcy identification ability.

Fluorescence-guided Surgery for Hepatocellular Carcinoma: From Clinical Practice to Laboratories

Fluorescence navigation is a novel technique for accurately identifying hepatocellular carcinoma (HCC) lesions during hepatectomy, enabling real-time visualization. Indocyanine green-based fluorescence guidance has been commonly used to demarcate HCC lesion boundaries, but it cannot distinguish between benign and malignant liver tumors. This review focused on the clinical applications and limitations of indocyanine green, as well as recent advances in novel fluorescent probes for fluorescence-guided surgery of HCC. It covers traditional fluorescent imaging probes such as enzymes, reactive oxygen species, reactive sulfur species, and pH-sensitive probes, followed by an introduction to aggregation-induced emission probes. Aggregation-induced emission probes exhibit strong fluorescence, low background signals, excellent biocompatibility, and high photostability in the aggregate state, but show no fluorescence in dilute solutions. Design strategies for these probes may offer insights for developing novel fluorescent probes for the real-time identification and navigation of HCC during surgery.

Phosphinylation/cyclization of propynolaldehydes to isobenzo-furanylic phosphine oxides displaying AIE properties

Investigating organic reactions to synthesize novel molecules that exhibit aggregation-induced emission (AIE) characteristics is becoming a research hotspot. Herein, we develop a one-pot phosphinylation/cyclization reaction between propynolaldehydes and diarylphosphine oxides to generate isobenzofuran-substituted phosphine oxides (IBFPOs) displaying AIE properties. Such a reaction possesses benefits such as metal-free synthesis, simple operation and wide substrate applicability. Further structural modifications of the products have been implemented through the palladium-catalyzed Sonogashira reaction, Ullmann coupling and Diels-Alder addition. Furthermore, these AIE luminogens (AIEgens), which have satisfactory quantum yields and tunable emission covering the entire visible region, can be employed for the cell imaging of lipid droplets in HeLa cells. Notably, quantitative evaluation of the phototherapy effect demonstrates that one of these presented AIEgens, namely IBFPO-3j, displays high type-I reactive oxygen species (ROS) generation efficiency, enabling its effective application in photodynamic therapy in a hypoxic environment.

Biomimetic NIR-II aggregation-induced emission nanoparticles for targeted photothermal therapy of ovarian cancer

Photothermal therapy (PTT) is a cutting-edge technique that harnesses light energy and converts it into heat for precise tumor ablation. By employing photothermal agents to selectively generate heat and target cancer cells, PTT has emerged as a promising cancer treatment strategy. Notably, therapies conducted in the second near-infrared (NIR-II) window exhibit superior therapeutic outcomes, owing to deeper tissue penetration and reduced light scattering. In this study, we developed biomimetic NIR-II aggregation-induced emission (AIE) nanoparticles (2TB-NPs@TM) for high-efficiency NIR-II imaging and targeted phototherapy of ovarian cancer. The core nanoparticle aggregates (2TB-NPs) display strong NIR-II fluorescence and high photothermal conversion efficiency, while the outer tumor cell membrane coating facilitates active targeting and precise recognition of tumor tissues. This design imparts excellent biocompatibility and enhances drug delivery efficiency, leading to potent synergistic therapeutic effects. Our findings open new avenues for advancing targeted, high-performance phototherapy diagnostics in cancer treatment.

Activatable peptide-AIEgen conjugates for cancer imaging

Aggregation-induced emission luminogens (AIEgens) have undergone significant development over the past decade, making substantial and profound contributions to a diverse range of research fields, prominently including cancer/disease diagnosis and therapy. Through the covalent conjugation of AIEgens with functional peptides, the resultant peptide-AIEgen conjugates possess not only the excellent biocompatibility characteristics, along with low systemic toxicity and negligible immunogenicity of peptides, but also the remarkable fluorescence properties of AIEgens. This "win-win" integration has significantly propelled the applications of peptide-AIEgen conjugates, particularly within the domain of cancer imaging. Three principal types of peptide-AIEgen conjugates, namely, tumor-targeting, tumor biomarker-responsive, and biomarker-responsive self-assembling peptide-AIEgen conjugates, are commonly devised. These conjugates confer enhanced targeting capabilities and selectivity towards tumors, thereby facilitating "smart" and precise tumor imaging with high signal-to-background ratios. In light of the crucial significance of peptide-AIEgen conjugates in tumor imaging and the recent inspiring breakthroughs that have not been encompassed in previous reviews, we present this review. We highlight the activatable peptide-AIEgen conjugates developed for tumor imaging over the past three years (from 2022 to the present). Particular attention is directed towards their design rationales, operational mechanisms, and imaging performance. Finally, prospective opportunities within this field are also reasonably deliberated.

Redox-Initiated RAFT Emulsion Polymerization-Induced Self-Assembly of β-Ketoester Functional Monomers

Amphiphilic block copolymers are essential for developing advanced polymer nanomaterials with applications in bioimaging, drug delivery, and nanoreactors. In this study, we successfully synthesized functional block copolymer assemblies at high concentrations through redox-initiated reversible addition-fragmentation chain transfer (RAFT) emulsion polymerization of 2-(acetoacetoxy)ethyl methacrylate (AEMA), a β-ketoester functional monomer. Utilizing a redox initiation system at 50 °C, we produced poly(poly(ethylene glycol) methyl ether methacrylate)-b-PAEMA (PPEGMAn-PAEMAm). Kinetic studies demonstrated rapid monomer conversion exceeding 95% within 30 min, with distinct polymerization phases driven by micelle formation and monomer depletion. Transmission Electron Microscopy (TEM) and Dynamic Light Scattering (DLS) revealed the formation of diverse morphologies, including worm-like, vesicular structures, and spherical micelles, depending on the macro-CTA molecular weight and monomer concentration. Additionally, post-polymerization modification with aggregation-induced emission (AIE) luminogens, such as 1-(4-aminophenyl)-1,2,2-tristyrene (TPE-NH2), resulted in AIE-active polymer assemblies exhibiting strong fluorescence in aqueous dispersions. These AIE-active polymer assemblies also exhibited good biocompatibility. These findings demonstrate the efficacy of redox-initiated RAFT emulsion polymerization in fabricating functional, scalable block copolymer assemblies with potential applications in the field of life sciences.

Advances in Tracing Techniques: Mapping the Trajectory of Mesenchymal Stem-Cell-Derived Extracellular Vesicles

Mesenchymal stem-cell-derived extracellular vesicles (MSC-EVs) are nanoscale lipid bilayer vesicles secreted by mesenchymal stem cells. They inherit the parent cell's attributes, facilitating tissue repair and regeneration, promoting angiogenesis, and modulating the immune response, while offering advantages like reduced immunogenicity, straightforward administration, and enhanced stability for long-term storage. These characteristics elevate MSC-EVs as highly promising in cell-free therapy with notable clinical potential. It is critical to delve into their pharmacokinetics and thoroughly elucidate their intracellular and in vivo trajectories. A detailed summary and evaluation of existing tracing strategies are needed to establish standardized protocols. Here, we have summarized and anticipated the research progress of MSC-EVs in various biomedical imaging techniques, including fluorescence imaging, bioluminescence imaging, nuclear imaging (PET, SPECT), tomographic imaging (CT, MRI), and photoacoustic imaging. The challenges and prospects of MSC-EV tracing strategies, with particular emphasis on clinical translation, have been analyzed, with promising solutions proposed.

Tuning the Near-Infrared J-Aggregate of a Multicationic Photosensitizer through Molecular Coassembly for Symbiotic Photothermal Therapy and Chemotherapy

Cationic photosensitizers (PSs) offer many intriguing advantages, in addition to generating heat or reactive oxygen species for cancer phototherapy. However, the preparation of cationic PSs with enhanced near-infrared (NIR) absorption remains a significant challenge. In this work, we have synthesized a PS TPBBT, which incorporates a strong electron-withdrawing unit, benzobisthiadiazole, and four terminal pyridinium groups. It self-assembles into a mixed H/J aggregated state with a maximal absorption peak at 620 nm but coassembles with negatively charged planar small molecules to form sole J-aggregates. Following this strategy, we coassemble TPBBT with rhein, a planar, anionic traditional Chinese medicine with an anticancer activity, which allows for a near 100 nm bathochromic shift of the maximal absorption of TPBBT and improves the photothermal conversion efficiency (PCE) of TPBBT from 6.4 to 60.4% under 808 nm laser irradiation. Additionally, coassembling with TPBBT significantly enhances the cellular uptake of rhein through the photothermal effect. The coassembly of TPBBT and rhein (TPBBTein) can completely eliminate 4T1 tumors on mouse models, validating that this facile strategy not only can tune the NIR J-aggregate of cationic PS through molecular coassembly but also promotes the efficient, symbiotic combination of photothermal therapy and chemotherapy.

Deep Learning Enhanced Near Infrared-II Imaging and Image-Guided Small Interfering Ribonucleic Acid Therapy of Ischemic Stroke

Small interfering RNA (siRNA) targeting the NOD-like receptor family pyrin domain-containing 3 (NLRP3) inflammasome has emerged as a promising therapeutic strategy to mitigate infarct volume and brain injury following ischemic stroke. However, the clinical translation of siRNA-based therapies is significantly hampered by the formidable blood-brain barrier (BBB), which restricts drug penetration into the central nervous system. To address this challenge, we have developed an innovative long-circulating near-infrared II (NIR-II) nanoparticle platform YWFC NPs, which is meticulously engineered to enhance BBB transcytosis and enable efficient delivery of siRNA targeting NLRP3 (siNLRP3@YWFC NPs) in preclinical models of ischemic stroke. Furthermore, we integrated advanced deep learning neural network algorithms to optimize in vivo NIR-II imaging of the cerebral infarct penumbra, achieving an improved signal-to-background ratio at 72 h poststroke. In vivo studies employing middle cerebral artery occlusion (MCAO) mouse models demonstrated that image-guided therapy with siNLRP3@YWFC NPs, guided by prolonged NIR-II imaging, resulted in significant therapeutic benefits.

Hierarchical Self-Assembly of J-Aggregated 1,2-Bis(2-(benzyloxy)benzylidene) Hydrazine@2β-Cyclodextrin into Left-Handed Superhelix and Its External Stimuli-Responsive Unwinding

Induction of chirality to nanosized superstructures from hierarchical self-assembly of achiral monomeric units is an important area to understand the natural chiral amplification and evolution of life processes. We report herein that the complexation of salicylaldehyde azine, 1,2-bis(2-(benzyloxy)benzylidene)hydrazine (BSAZ), with β-cyclodextrin (β-CD) in aqueous solution results in the formation of a slipped J-aggregate (θ < 54.7°) that aggregates further into a left-handed superhelix through sterical constraints triggered by the hydrophobic effect. The structure of the monomeric BSAZ@2β-CD was elucidated by ultraviolet-visible (UV-vis), Fourier transform infrared spectroscopy (FT-IR), mass, powder X-ray diffraction (PXRD), and 1H, 13C, and 13C CP/MAS nuclear magnetic resonance (NMR) spectroscopy. The size, shape, and morphology of the self-aggregated hierarchy were evidenced by dynamic light scattering (DLS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) studies. The system showed excellent aggregation induced circular dichroism (AICD) with a negative Cotton effect and a high fluorescence quantum yield of 0.33 at 620 nm in a poor solvent, water, because of the formation of a higher order excimer (N ≈ 46). The helical superstructure showed responsiveness under 254 nm UV light irradiation. Light irradiation slowly unwinds the supercoiled structure into a single strand, as was visualized by a SEM image taken after 15 min of continuous light irradiation. The excellent solvatochromic effect and the control over the formed hierarchical morphology show how a supramolecular approach tailored by noncovalent interactions can develop chiral superstructures from completely achiral molecular building blocks that would have a considerable practical value in chiroptics, templates, and chiral sensing.

Biological AIE Molecules: Innovations in Synthetic Design and AI-Driven Discovery

Biological aggregation -induced emission (AIE) molecules offer significant advantages over synthetic organic fluorophores, particularly in biocompatibility, environmental sustainability, and emission properties in biological systems. Derived from biomolecules such as peptides, proteins, and nucleic acids, biological AIE molecules hold great promise for applications in biosensing, bioimaging, and target drug delivery. This review explores the design principles, mechanistic insights, and functional properties of biological AIE molecules whiles highlighting the role of artificial intelligence (AI) in accelerating their discovery and optimization. AI-driven approaches, including machine learning and computational modeling, are transforming the identification and synthesis of AIE molecules by enabling precise structural modifications and enhanced fluorescence efficiency. These advancements are paving the way for the integration of AIE molecules in next-generation smart biomedical devices, personalized medicine and sustainable technological applications. Emerging trends, including hybrid biomaterials, Ai-guided molecular engineering, and advanced imaging techniques, are expanding the scope of biological AIE molecules in healthcare and environmental monitoring. The synergy between AI and biological AIE molecules is unlocking new frontiers in biomedical technology, enabling transformative advancements in material science and healthcare applications, and shaping the future of fluorescence- based diagnostics and therapeutics.

Carborane-Decorated Siloles with Highly Efficient Solid-State Emissions - What Drives the Photophysical Properties?

New hybrids were synthesised by linking carboranes and siloles, both of which are known as aggregation-induced emission active units. Although most of the newly synthesised systems do not display notable quantum yield either in solution or in the aggregated state, they emit strongly in the solid-state, and a quantum yield of up to 100 % can be achieved. The tailorable quantum yield can be attributed to the packing of the molecules in the crystal lattice ruled by the carborane and phenyl moieties according to the SC-XRD data. Our experimental results, complemented by density functional theory calculations, show that the silole moiety primarily influences the photophysical properties. At the same time, the carborane serves as a steric building block without direct responsibility for the aggregation-induced emission property. The patterns of substituents can alter the absorption and emission properties.

Exploring the sensing properties of pH-sensitive carbazole-based AIE emitters and their applications in paper strip sensing

A novel carbazole-coupled phenanthridine molecule with an intense blue emissive fluorescence was produced through a two-step synthesis of 5-(4-(9H-carbazol-9-yl)phenyl)-7,8,13,14-tetrahydrodibenzo[a,i]phenanthridine (DSPH). This blue probe shows a good thermal and electrochemical stability. It has been used for sensing trifluoracetic acid (TFA) with a limit of detection (LoD) value of 198 pM. The probe tends to show aggregation induced emission (AIE) characteristics. Additionally, the experimental data were supported by DFT analysis.

Aggregation-induced emission and absorption enhancement of mixed-valent rhenium oxide quantum dots by triethylamine: Implications for food safety monitoring

Food freshness monitoring and volatile amine detection are key to food safety. In this study, we demonstrated the applicability of mixed-valence rhenium oxide quantum dots (MV-ReOQDs), synthesized via the hydrothermal reaction of α-cyclodextrin and rhenium ion precursors, in triethylamine (TEA) sensing. Spectroscopic correlation techniques showed that the developed MV-ReOQDs possessed mixed-valent rhenium, α-cyclodextrin as capped ligand, partially carbonized surface, and amorphous phase structure. The multiple oxidation states in the MV-ReOQDs facilitated electron precipitation, contributing to increased excitation-dependent emission, broadened absorption band, and extended luminescence lifetime with increasing emission wavelength. TEA was found to trigger aggregation-induced emission enhancement (AIEE) in the MV-ReOQDs owing to hydrophobic inclusions and hydrogen bonding. Moreover, TEA engaged in charge-transfer interactions with the MV-ReOQDs, amplifying their visible absorption. The MV-ReOQDs afford a limit of detection (signal-to-noise ratio of 3) for TEA at 5 µM (0.5 ppm) for colorimetric detection and 700 nM (0.071 ppm) in luminescent detection modes. Embedding the MV-ReOQDs onto a filter paper yielded a straightforward tool for the real-time detection of TEA vapors released during shrimp spoilage. This MV-ReOQD-coated filter paper provides a convenient solution for monitoring food freshness and facilitates safer food handling and quality control practices.

Lateral flow analysis test strips based on aggregation-induced emission technique: Principle, design, and application

This review examines the potential of aggregation-induced luminescence (AIE) materials in lateral flow assays (LFA) to enhance the sensitivity and specificity of a range of assay applications. LFA is a straightforward and effective paper-based platform for the rapid detection of target analytes in mixtures. Its simple design, low cost, and ease of operation are among the most attractive advantages of LFA. The signal reporting label, which constitutes the core component of LFA detection, is of paramount importance for enhancing the sensitivity of the detection process. The sensitivity of traditional LFA signal labels is insufficient for the detection of biomarkers at low concentrations. To address this issue, AIE materials have been developed in recent years. These materials can significantly enhance the luminescence intensity at high concentrations or in aggregated states, exhibiting excellent photostability and a high signal-to-noise ratio. They possess the advantages of high quantum yields, good photostability, and strong fluorescence, rendering them suitable for a variety of applications, including medical diagnostics, food safety, and environmental monitoring. This review therefore provides an overview of the operational principles of AIE and LFA, details the selection of AIE materials, the design of the platform and their applications, and reviews the latest research. Notable examples include the detection of viral pathogens, bacterial and mycotoxin contamination, antibiotic residues, and pesticide residues. The integration of AIE materials in LFA technology has demonstrated the potential for rapid, accurate, and cost-effective diagnostics. However, challenges remain in large-scale synthesis and multiplexed assays. The paper concludes with a discussion of current limitations and future directions for the technology.

Non-conjugated alkyl chain engineering to tune condensed state photophysical and supramolecular assembly properties

Techniques utilizing strategic molecular engineering to develop well-defined supramolecular fluorescent nano-assemblies hold significant scientific interest. However, a significant drawback in their practical application is the undesirable aggregation-caused quenching (ACQ) phenomenon in traditional fluorescent compounds, which usually occurs in planar aromatic cores. Herein, a series of seven planar naphthalimide (NC) derivatives have been constructed by appending non-conjugated linear alkyl chains that effectively modulate their condensed state emission and supramolecular nano-assembly. Structural characterization through single-crystal X-ray diffraction (SCXRD) and powder X-ray diffraction (PXRD) patterns indicates that the supramolecular nano-assemblies and their condensed state emission properties are intricately governed by the alkyl chain-driven intermolecular packing orientation. The steric constraints exerted by the non-conjugated linear alkyl chains appended to the NC core efficiently alter the intermolecular π-π stacking interactions of the planar aromatic core. The investigated role of linear alkyl chains in modulating the condensed state behavior of NC derivatives presents a conceptual insight and a promising avenue for constructing fluorescent nano-assemblies.

Recent Progress in Radiosensitive Nanomaterials for Radiotherapy-Triggered Drug Release

Benefiting from the unique properties of ionizing radiation, such as high tissue penetration, spatiotemporal resolution, and clinical relevance compared with other external stimuli, radiotherapy-induced drug release strategies are showing great promise in developing effective and personalized cancer treatments. However, the requirement of high doses of X-ray irradiation to break chemical bonds for drug release limits the application of radiotherapy-induced prodrug activation in clinics. Recent advances in nanomaterials offer a promising approach for radiotherapy sensitization as well as integrating multiple modalities for improved therapy outcomes. In particular, the catalytic radiosensitization that utilizes electrons and energy generated by nanomaterials upon X-ray irradiation has demonstrated excellent potential for enhanced radiotherapy. In this Review, we summarize the design principles of X-ray-responsive chemical bonds for controlled drug release, strategies for catalytic radiosensitization, and recent progress of X-ray-responsive nanoradiosensitizers for enhanced radiotherapy by integration with chemotherapy, chemodynamic therapy, photodynamic therapy, photothermal therapy, gas therapy, and immunotherapy. Finally, we discuss the challenges of X-ray-responsive nanoradiosensitizers heading toward possible clinical translation. We expect that emerging strategies based on radiotherapy-triggered drug release will facilitate a frontier in accurate and effective cancer therapy in the near future.