Search Results (200)

The development of rapid detection methods to identify mercury ions in aqueous solutions is crucial for effectively monitoring environmental contamination. Fluorescent chemical sensors offer a fast and reliable approach to detect and analyze these metal ions. In this study, a sensor utilizing aggregation-induced emission (AIE) is introduced as a ’turn-on’ fluorescent sensor specifically designed for mercury ions in aqueous solutions. The sensor, based on carbazole, forms aggregates in aqueous solutions, resulting in a significant 800% enhancement of its fluorescence signal. When elemental iodine is added to the solution, the fluorescence of the aggregates is quenched by 90%. However, upon subsequent addition of mercury ions, the fluorescence is regenerated, and the intensity of the emission signal is directly proportional to the concentration of the ions across a wide concentration range. The carbazole-iodine complex acts as a fluorescent probe, enabling the detection of mercury ions in aqueous solutions. Full article

Amyloid-β (Aβ) aggregates are considered as the important factors of Alzheimer’s disease (AD). Multifunctional materials have shown significant effects in the diagnosis and treatment of AD by modulating the aggregation of Aβ and production of reactive oxygen species (ROS). Compared to traditional surgical treatment and radiotherapy, phototherapy has the advantages, including short response time, significant efficacy, and minimal side effects in disease diagnosis and treatment. Recent studies have shown that local thermal energy or singlet oxygen generated by irradiating certain organic molecules or nanomaterials with specific laser wavelengths can effectively degrade Aβ aggregates and depress the generation of ROS, promoting progress in AD diagnosis and therapy. Herein, we outline the development of photothermal therapy (PTT) and photodynamic therapy (PDT) strategies for the diagnosis and therapy of AD by modulating Aβ aggregation. The materials mainly include organic photothermal agents or photosensitizers, polymer materials, metal nanoparticles, quantum dots, carbon-based nanomaterials, etc. In addition, compared to traditional fluorescent dyes, aggregation-induced emission (AIE) molecules have the advantages of good stability, low background signals, and strong resistance to photobleaching for bioimaging. Some AIE-based materials exhibit excellent photothermal and photodynamic effects, showing broad application prospects in the diagnosis and therapy of AD. We further summarize the advances in the detection of Aβ aggregates and phototherapy of AD using AIE-based materials. Full article

Carbon dots (CDs), a class of carbon-based fluorescent nanomaterials, have garnered significant attention due to their tunable optical properties and functional versatility. In this study, we developed a hybrid material by grafting pH- and temperature-responsive copolymers onto CDs via reversible addition-fragmentation chain-transfer (RAFT) polymerization. Triamino-tetraphenylethylene (ATPE) and N-isopropylacrylamide (NIPAM) were copolymerized at varying ratios and covalently linked to CDs, forming a dual-responsive system. Structural characterization using FTIR, ¹H NMR, and TEM confirmed the successful grafting of the copolymers onto CDs. The hybrid material exhibited pH-dependent fluorescence changes in acidic aqueous solutions, with emission shifting from 450 nm (attributed to CDs) to 500 nm (aggregation-induced emission, AIE, from ATPE) above a critical pH threshold. Solid films of the hybrid material demonstrated reversible fluorescence quenching under HCl vapor and recovery/enhancement under NH₃ vapor, showing excellent fatigue resistance over multiple cycles. Temperature responsiveness was attributed to the thermosensitive poly(NIPAM) segments, with fluorescence intensity increasing above 35 °C due to polymer chain collapse and ATPE aggregation. This work provides a strategy for designing multifunctional hybrid materials with potential applications in recyclable optical pH/temperature sensors. Full article

Electrochemiluminescence (ECL) biosensors based on aggregation-induced emission (AIE) emitters have recently emerged as highly sensitive tools for biosensing. The AIE phenomenon, characterized by a significant luminescence change upon aggregation due to restricted intramolecular rotation or vibration, effectively enhances ECL intensity and efficiency, endowing AIECL emitters with high selectivity and stability. This review provides an overview of the developmental trajectory of AIECL, systematically elaborates and comparatively analyzes the mechanisms and luminophore systems of conventional ECL and AIECL, discusses the design strategies and construction methods of AIECL luminophores, and comprehensively summarizes the innovative applications of AIECL in the realm of biosensors. Finally, some of the current challenges in this emerging field are outlined, along with perspectives on future trends. Full article

Hypochlorous acid (HClO) serves as a biological mediator and is widely utilized as a disinfectant in food processing and water treatment. However, excessive HClO residues in food and environmental water raise concerns due to the potential formation of carcinogenic chlorinated byproducts and disinfection byproducts (DBPs). Despite its importance, traditional methods for HClO detection often involve complex sample preparation, sophisticated instrumentation, and skilled operators. Herein, we report an aggregation-induced emission (AIE) small molecule fluorescent probe (NYV) that integrates colorimetric and ratiometric fluorescence responses for the detection of HClO. This probe exhibits high sensitivity, with a detection limit of 0.35 $\mathsf{\mu }$M, a rapid response time of 1 min, and a wide linear range (0–142.5 $\mathsf{\mu }$M), along with anti-interference capabilities, making it suitable for real-time monitoring. Furthermore, we have developed a portable solid-state sensor based on probe NYV for the rapid visual detection of HClO. The potential applications of this probe in real sample analysis and bioimaging experiments are demonstrated. Our findings contribute to the development of innovative fluorescent probes for HClO detection, with broad applications in food safety, environmental monitoring, and biomedical research on oxidative stress and ferroptosis. Full article

Nanotechnology is transforming contemporary medicine by providing cutting-edge tools for the treatment and diagnosis of complex disorders. Advanced techniques such as bioimaging and photodynamic therapy (PDT) combine early diagnosis and targeted therapy, offering a more precise approach than conventional treatments. However, a significant obstacle for PDT is the need to selectively deliver photosensitizers to disease sites while minimizing systemic side effects. In this context, mesenchymal stem cells have emerged as promising biological carriers due to their natural tropism towards tumors, low immunogenicity, and their ability to overcome biological barriers. In this study, two push–pull compounds, NPI-PTZ and BTZ-PTZ, phenothiazine derivatives featuring aggregation-induced emission (AIE) abilities, were analyzed. These molecules proved to be excellent fluorescent probes and photosensitizing agents. When administered to human bone marrow-derived multipotent stromal cells (hBM-MSCs) and human adipose multipotent stem cells (hASCs), the compounds were efficiently internalized, maintained a stable fluorescent emission for several days, and showed phototoxicity after irradiation, without inducing major cytotoxic effects under normal conditions. These results highlight the potential of NPI-PTZ and BTZ-PTZ combined with mesenchymal stem cells as theranostic tools, bridging bioimaging and PDT, and suggest new possibilities for advanced therapeutic approaches in clinical applications. Full article

Photochromic materials have attracted widespread attention due to their potential applications in optical information storage, optoelectronic devices, and fluorescence probes. As a typical photochromic system, diarylethene derivatives are considered one of the most promising photochromic materials due to their outstanding photostability and significant bistable properties. Based on an aggregation-induced emission (AIE) mechanism, this study employed a molecular structural engineering strategy to design and synthesize a series of diarylethene derivatives containing ethyl benzoate substituents. A systematic investigation of the structure–activity relationship between their photochromic behavior and AIE characteristics revealed a dual-state light response mechanism in the solid and solution states. This study demonstrates that the target compounds exhibited significant photochromic responses under UV–visible light irradiation, with enhanced emission in the solid state compared to the solution state, confirming the remarkable enhancement effect of AIE on aggregation. Structural characterization techniques such as nuclear magnetic resonance spectroscopy (NMR) and high-resolution mass spectrometry (H RMS) were employed to elucidate the correlation between molecular conformation and photophysical properties. Furthermore, these materials demonstrated potential for multi-level anti-counterfeiting, high-density optical storage, and bioimaging applications, providing experimental foundations for the development of novel multifunctional photochromic materials. Full article

Single-phase white-light-emitting materials, particularly 2D hybrid organic–inorganic halide perovskites, have garnered significant attention due to their strong electron–phonon interactions, which lead to broad luminescence and a notable Stokes shift resulting from self-trapped exciton recombination. However, 2D lead iodide perovskites typically display these characteristics poorly, restricting their efficiency as white-light emitters. This study presents a 2D lead iodide perovskite that incorporates a fluorinated π-conjugated aggregation-induced enhanced emission luminophore, FPCSA, as a bulky organic cation to create a quasi-2D perovskite. The FPCSA cation establishes a Type II energy level alignment with the lead iodide layer in the 2D perovskite, and a significant energy offset effectively suppresses charge transfer, enabling independent emission from both the organic and inorganic layers while facilitating self-trapped exciton formation. Under 315 nm UV excitation, this material demonstrates warm white-light emission with RGB triple-band photoluminescence stemming from the electronically decoupled FPCSA and perovskite layers. These findings provide a promising new method for designing efficient single-phase white-light-emitting materials for optoelectronic applications. Full article

Fluorescent sensors are indispensable tools in fields such as molecular biology, clinical diagnostics, biotechnology, and environmental monitoring, due to their high sensitivity, selectivity, biocompatibility, rapid response, and ease of use. However, conventional fluorophores often suffer from aggregation-caused quenching (ACQ), leading to diminished fluorescence in the aggregated state. The advent of aggregation-induced emission (AIE) luminogens, which exhibit enhanced fluorescence upon aggregation, offers a powerful solution to this limitation. Their unique photophysical properties have made AIE-based materials highly valuable for diverse applications, including biomedical imaging, optoelectronics, stimuli-responsive systems, drug delivery, and chemical sensing. Notably, AIE-based fluorescent probes are emerging as attractive alternatives to traditional analytical methods owing to their low cost, fast detection, and high selectivity. Over the past two decades, considerable progress has been made in the rational design and development of AIE-active small-molecule fluorescent probes for detecting a wide variety of analytes, such as biologically relevant molecules, drug compounds, volatile organic compounds (VOCs), explosives, and contaminants associated with forensic and food safety analysis. This review highlights recent advances in organic AIE-based fluorescent probes, beginning with the fundamentals of AIE and typical “turn-on” sensing mechanisms, and concluding with a discussion of current challenges and future opportunities in this rapidly evolving research area. Full article

Conjugated polymers (CPs) have emerged as promising candidates for photodynamic therapy (PDT) in cancer treatment due to their high fluorescence quantum yield, excellent photostability, and remarkable reactive oxygen species (ROS) generation capability. This review systematically summarizes molecular design strategies to augment CP photosensitivity efficiency, including: (1) constructing donor–acceptor (D-A) alternating structures, (2) incorporating aggregation-induced emission (AIE) moieties, (3) employing heavy-atom effects, and (4) designing hyperbranched architectures. In addition, considering the limitations of monotherapy like tumor heterogeneity, we will further discuss the synergistic treatment strategies of CP-mediated PDT in combination with other therapeutic modalities, including photothermal therapy (PTT)-PDT, immunotherapy-PDT, chemotherapy-PDT, Chemiluminescence (CL)-PDT, diagnostic technology-PDT, and chemodynamic therapy (CDT)-PDT. These multimodal approaches leverage complementary mechanisms to achieve enhanced tumor eradication efficacy. Full article

This study reports the synthesis, characterization, and property analysis of four novel multilayer 3D polymers (1A to 1D) with 1,3-phenyl bridge architectures spanning 248 to 320 layers. High-molecular-weight polymers were successfully synthesized via catalytic Suzuki–Miyaura cross-coupling over a four-day reaction period. Structures, thermal, and optical properties were examined using multiple analytical techniques. Fourier transform-infrared (FT-IR) spectroscopy was used to study the hydrogen bonding within the polymer system, suggesting the formation of the polymer through the Suzuki–Miyaura coupling reaction. Ultraviolet–visible (UV-vis) spectroscopy indicated strong electronic delocalization, with maximum absorbance peaks between 257 and 280 nm. Thermal characterization, using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA), was used to investigate the thermal stability. TGA results showed that all four polymers retained more than 20% of their initial mass at 1000 °C, indicating good thermal stability across the series. DSC analysis revealed that polymer 1A exhibited a glass transition temperature (Tg) of 167 °C, indicating the presence of a network formed by aromatic conjugation and hydrogen bonding. Furthermore, the subtle Tg step observed for 1A suggests a degree of crystallinity within the polymer matrix, which was further supported by X-ray diffraction (XRD) analysis. Aggregation-induced emission (AIE) experiments provided further insights into intermolecular packing, and scanning electron microscopy (SEM) contributed to a better understanding of the morphology of the obtained polymers. These results highlight the potential of these polymers as thermally stable and conductive materials for biomedical and industrial applications. Full article

We report the design and biological evaluation of a nanoplatform featuring controllable aggregation-induced emission (AIE) behavior. The free rotation of benzene rings (4-(1,2,2-triphenylvinyl) benzaldehyde) largely suppresses fluorescence in the pure organic phase. However, water-induced molecular aggregation enhances the fluorescence signal. The delivery system follows the membrane–cytoplasm–nucleus route and it leads to apoptosis in two cancer cells (U937 cells and Hela cells). The AIE moiety accumulates in the cytoplasm, emitting a bright-blue signal, but the anticancer drug doxorubicin selectively targets the nucleus with unique red emission. The current noninvasive method with DOX-triggered apoptosis holds promise for tumor diagnosis and real-time imaging. Full article

Mercury and explosives are well-known hazards that affect the environment and threaten society. Mercury generally exists as inorganic mercuric (Hg²⁺) salts, and its detection via fluorometric response is highly notable. Likewise, mainstream explosives contains a nitro (−NO₂) moiety as a functional unit, and numerous reports have quantified them using fluorescence quenching. Among the available literature, there are still noticeable concerns about the environmental and biological applicability of luminescent pyrene derivaives-tunedfluorometric detection of Hg²⁺ and explosives. In the presence of Hg²⁺ ions, pyrene derivatives tend to form excimers, which can be tuned to the chelation-enhanced fluorescence (CHEF), photo-induced electron transfer (PET), or fluorescence resonance energy transfer (FRET), etc., to exhibit “Turn-On” or “Turn-Off” fluorescence responses. On the other hand, π-π stacking of emissive pyrene-derivatives may lead to J- or H-type aggregation via self-excimers (Py-Py*), which has been found to be quenched/enhanced by explosive hazards. In fact, −NO₂-containing explosives interact with pyrene derivatives, leading to exceptional fluorescence quenching or enhancement. This review details the use of pyrene derivatives toward the sensing of Hg²⁺ and explosives with demonstrated applications. Further, the design requirements, sensory mechanisms, advantages, limitations, and the future scope of using the reported pyrene derivatives in Hg²⁺ and explosives sensing are discussed. Full article

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. Full article

This study reports the synthesis of novel multilayer 3D chiral polymers using 2,2′-(2,7-Naphthalenediyl)bis[4,4,5,5-tetramethyl-1,3,2-dioxaborolane] and 1,8-dibronaphthalene along with its derivatives as key precursors. Comprehensive characterization was performed using nuclear magnetic resonance (NMR), gel permeation chromatography (GPC), photoluminescence, ultraviolet (UV) spectroscopy, scanning electron microscopy (SEM), polarimetry, dynamic light scattering (DLS), and thermogravimetric analysis (TGA). Notably, the polymers exhibited remarkable aggregation-induced emission (AIE) and aggregation-induced polarization (AIP) phenomena, revealing enhanced luminescence and optical activity in aggregated states. These findings underscore the potential of these chiral polymers for applications in optoelectronics and advanced sensing technologies, highlighting the intricate relationship between molecular structure and optical behavior. Full article