Aggregation-induced Emission Molecules Research Articles

Electronic structure modulation in quinoline derivatives through substituent-mediated effects: Development of AIE fluorescent probes for Fe3+ detection in water samples

Iron (Fe3+) is an essential trace element in biological organisms. Abnormal concentrations of Fe3+ in aquatic possess the potential to disrupt normal physiological and metabolic processes in living organisms. Consequently, the pursuit of developing fluorescent probes for detecting Fe3+ concentrations in water samples is highly significant. The lone electron pair on the nitrogen atom of quinoline demonstrates outstanding coordination capabilities, enabling the selective detection of metal ions through coordination. Nevertheless, the interaction between metal ions and quinoline-based fluorescent probes tends to lead to nanoparticle aggregation, causing aggregation-caused quenching (ACQ) phenomena. This severely restricts the practical application of these probes. To address this challenge, the study utilizes quinoline as the foundational framework and modulates the excited-state electronic structure of quinoline derivatives through substituent effects. This facilitates the transition from ACQ to aggregation-induced emission (AIE). By integrating theoretical calculations, the paper proposes a comprehensive strategy for designing AIE molecules based on quinoline. This contribution provides innovative perspectives on AIE molecule design. Ultimately, the AIE property of the 8-MQB molecule is harnessed to develop a fluorescent probe capable of detecting Fe3+ in water samples. The fluorescence intensity exhibits a robust linear correlation with Fe3+ concentrations within the range of 5.0 μM to 0.3 mM. Moreover, the probe demonstrates exceptional resistance to interference from other metal ions. In conclusion, this research presents a universal strategy for designing AIE molecules and introduces an AIE probe for the rapid detection of Fe3+ concentrations in water samples.

AIE-doped agar-based photodynamic sterilization film for antimicrobial food wrapping

Agar film for food wrapping is popular because of its low price, edible and strong biodegradability. However, there are still many problems in the application of agar film, such as no antibacterial performance. To address the problem, we designed and synthesized a novel photodynamic bactericidal aggregation-induced emission (AIE) molecule, then mixed it into agar to prepare a composite film, which made the agar film have antimicrobial properties. Due to the antimicrobial ability of the AIE molecules, the agar-based composite film doped with AIE has a good inhibitory effect on E. coli, S. aureus, C. albicans, A. baumannii, P. aeruginosa and P. leiognathi. The actual fresh-keeping performance of wrapped pork was evaluated, and the results showed that it could extend the shelf life of pork to more than 8 days. In addition, the light transmittance, mechanical properties, water resistance, water permeability and thermal stability of the composite film remain good. Therefore, the application of AIE-doped agar-based film in food antimicrobial wrapping materials has a good prospect.

ROF-2 as an Aggregation-Induced Emission (AIE) Probe for Multi-Target Amyloid Detection and Screening of Amyloid Inhibitors.

Misfolding and aggregation of amyloid peptides into β-structure-rich fibrils represent pivotal pathological features in various neurodegenerative diseases, including Alzheimer's disease (AD), type II diabetes (T2D), and medullary thyroid carcinoma (MTC). The development of effective amyloid detectors and inhibitors for probing and preventing amyloid aggregation is crucial for diagnosing and treating debilitating diseases, yet it poses significant challenges. Here, an aggregation-induced emission (AIE) molecule of ROF2 with multifaceted functionalities as an amyloid probe and a screening tool for amyloid inhibitors using different biophysical, cellular, and worm assays, are reported. As an amyloid probe, ROF2 outperformed ThT, demonstrating its superior sensing capability in monitoring, detecting, and distinguishing amyloid aggregates of different sequences (Amyloid-β, human islet amyloid polypeptide, or human calcitonin) and sizes (monomers, oligomers, or fibrils). More importantly, the utilization of ROF2 as a screening molecule to identify and repurpose cardiovascular drugs as amyloid inhibitors is introduced. These drugs exhibit potent amyloid inhibition properties, effectively preventing amyloid aggregation and reducing amyloid-induced cytotoxicity both in cells and nematode. The findings present a novel strategy to discovery AIE-based amyloid probes and to be used to repurpose amyloid inhibitors, expanding diagnostic and therapeutic options for neurodegenerative diseases while addressing vascular congestion and amyloid aggregation risks.

Hybrid Water-Harvesting Channels Delivering Wide-Range and Supersensitive Passive Fluorescence Humidity Sensors.

The development of optical humidity detection has been of considerable interest in highly integrated wearable electronics and packaged equipment. However, improving their capacities for color recognition at ultralow humidity and response-recovery rate remains a significant challenge. Herein, we propose a type of hybrid water-harvesting channel to construct brand-new passive fluorescence humidity sensors (PFHSs). Specifically, the hybrid water-harvesting channels involve porous metal-organic frameworks and a hydrophilic poly(acrylic acid) network that can capture water vapors from the ambient environment even at ultralow humidity, into which polar-responsive aggregation-induced emission molecules are doped to impart humidity-sensitive luminescence colors. As a result, the PFHSs exhibit clearly defined fluorescence signals within 0-98% RH coupling with desirable performances such as a fast response rate, precise quantitative feedback, and durable reversibility. Given the flexible processability of this system, we further upgrade the porous structure via electrostatic spinning to furnish a kind of Nano-PFHSs, demonstrating an impressive response time (<100 ms). Finally, we validate the promising applications of these sensors in electronic humidity monitoring and successfully fabricate a portable and rapid humidity indicator card.

GSH-Responsive Liposomes with Heat Shock Protein Regulatory Ability for Efficient Photodynamic/Photothermal Combined Therapy of Tumors.

Phototherapy, represented by photodynamic therapy (PDT) and photothermal therapy (PTT), has great potential in tumor treatment. However, the presence of antioxidant glutathione (GSH) and the heat shock proteins (HSPs) expression caused by high temperature can weaken the effects of PDT and PTT. Here, a multifunctional nanocomplex BT&GA@CL is constructed to realize enhanced synergistic PDT/PTT. Cinnamaldehyde liposomes (CLs) formed by cinnamaldehyde dimer self-assembly were loaded with in gambogic acid (GA) and an aggregation-induced emission molecule BT to obtain BT&GA@CL. As a drug carrier, CL can consume glutathione (GSH) and release drugs responsively. The released BT aggregates can simultaneously act as both a photothermal agent and photosensitizer to achieve PDT and PTT under 660 nm laser irradiation. Specifically, GA as an HSP90 inhibitor can attenuate PTT-induced HSP90 protein expression, thereby weakening the tolerance of tumor cells to high temperatures and enhancing PTT. Such a multifunctional nanocomplex simultaneously modulates the content of GSH and HSP90 in tumor cells, thus enhancing both PDT and PTT, ultimately achieving the goal of efficient combined tumor suppression.

Multistimuli-responsive tetraphenylethene molecular switches displaying acid-sensing, photochromism, and metal ion detection properties

Aggregation-induced emission (AIE) smart materials with multiple stimulus responses have a wide range of applications. Here, a series of tetraphenylethylene (TPE) derivatives, TPEN1S3, TPEN2S2, TPEN3S1 were synthesized. The sensitivity of molecules to pH, UV light, and metal ions could be effectively tuned by modulating the ratio of amino to sulfonic acid groups. These TPE derivatives exhibited yellow emissions in aggregated state due to the AIE characteristics. Acidification conversion of the NH2 groups to NH3+ for three molecules induced the suppression of intramolecular charge transfer (ICT), which resulted in a 72–102 nm blue shift in the fluorescence emission. Solid powders of these compounds exhibited reversible protonation-deprotonation process induced by HCl/NH3·H2O vapor. TPEN1S3, TPEN2S2 and TPEN3S1 in solution could be photoactivated and emit blue fluorescence (ca. 482 nm, 475 nm, and 480 nm). Photocyclo-dehydrogenation reactions of compounds were triggered by the UV irradiation and the maximum cyclization ratios could reach 12%, 66%, and 50%, respectively. Protonation of NH2 group significantly enhanced the rate of the photocyclo-dehydrogenation reaction. Furthermore, the solid powders of protonated compounds displayed pronounced reversible photochromic properties due to the generation of cyclization intermediate. In addition, TPEN1S3, TPEN2S2, and TPEN3S1 exhibited responsiveness to a diverse range of metal ions. Specifically, the TPEN2S2 molecule functioned as a photo sensor for Li + ions with a blue shift in fluorescence emission. The limit of detection (LOD) value was 0.679 μM. These multiple stimuli-responsive AIE molecules hold significant potential for use in advanced photo-controlled patterning, encryption applications, and the detection of metal ions.

In Situ Monitoring and Tuning Multilayer Stacking of Polymer Lamellar Crystals in Solution with Aggregation-Induced Emission.

Many types of self-assembled 2D materials with fascinating morphologies and novel properties have been prepared and used in solution. However, it is still a challenge to monitor their in situ growth in solution and to control the number of layers in these materials. Here, we demonstrate that the aggregation-induced emission (AIE) effect can be applied for the in situ decoupled tracing of the lateral growth and multilayer stacking of polymer lamellar crystals in solution. Multilayer stacking considerably enhances the photoluminescence intensity of the AIE molecules sandwiched between two layers of lamellar crystals, which is 2.4 times that on the surface of monolayer crystals. Both variation of the self-seeding temperature of crystal seeds and addition of a trace amount of long polymer chains during growth can control multilayer lamellar stacking, which are applied to produce tunable fluorescent patterns for functional applications.

Multimodal phototherapy agents target lipid droplets for near-infrared imaging-guided type I photodynamic/photothermal therapy

The construction and optimization of a single phototherapeutic agent with photoluminescence, type I photodynamic therapy (PDT), and photothermal therapy (PTT) functions remain challenging. In this study, we aimed to design and synthesize four donor–acceptor (D-A) type aggregation-induced emission molecules: PSI, TPSI, PSSI, and TPSSI. We employed phenothiazine as an electron donor and 1,3-bis(dicyanomethylidene)indan as a strong electron acceptor in the synthesis process. Among them, TPSSI exhibited efficient type I reactive oxygen species generation, high photothermal conversion efficiency (45.44 %), and near-infrared emission. These observations can be attributed to the introduction of a triphenylamine electron donor group and a thiophene unit, which resulted in increased D–A strengths, a reduced singlet-triplet energy gap, and increased free intramolecular motion. TPSSI was loaded into bovine serum albumin to prepare biocompatible TPSSI nanoparticles (NPs). Our results have indicated that TPSSI NPs can target lipid droplets with negligible dark toxicity and can efficiently generate O2•− in hypoxic tumor environments. Moreover, TPSSI NPs selectively targeted 4T1 tumor tissues and exhibited a good PDT-PTT synergistic effect in vitro and in vivo. We believe that the successful preparation of multifunctional phototherapeutic agents will promote the development of efficient tumor diagnosis and treatment technologies. Statement of SignificanceThe construction of a single phototherapeutic agent with photoluminescence, type I photodynamic therapy, and photothermal therapy functions, and its optimization remain challenging. In this study, we construct four donor–acceptor aggregation-induced emission molecules using phenothiazine as an electron donor and 1,3-Bis(dicyanomethylidene)indan as a strong electron acceptor. By optimizing the molecular structure, an integrated phototherapy agent with fluorescence imaging ability and high photodynamic / photothermal therapy performance was prepared. We believe that the successful preparation of multifunctional phototherapeutic agents will promote the development of efficient tumor diagnosis and treatment technology.

Machine Learning Prediction of Quantum Yields and Wavelengths of Aggregation-Induced Emission Molecules.

The aggregation-induced emission (AIE) effect exhibits a significant influence on the development of luminescent materials and has made remarkable progress over the past decades. The advancement of high-performance AIE materials requires fast and accurate predictions of their photophysical properties, which is impeded by the inherent limitations of quantum chemical calculations. In this work, we present an accurate machine learning approach for the fast predictions of quantum yields and wavelengths to screen out AIE molecules. A database of about 563 organic luminescent molecules with quantum yields and wavelengths in the monomeric/aggregated states was established. Individual/combined molecular fingerprints were selected and compared elaborately to attain appropriate molecular descriptors. Different machine learning algorithms combined with favorable molecular fingerprints were further screened to achieve more accurate prediction models. The simulation results indicate that combined molecular fingerprints yield more accurate predictions in the aggregated states, and random forest and gradient boosting regression algorithms show the best predictions in quantum yields and wavelengths, respectively. Given the successful applications of machine learning in quantum yields and wavelengths, it is reasonable to anticipate that machine learning can serve as a complementary strategy to traditional experimental/theoretical methods in the investigation of aggregation-induced luminescent molecules to facilitate the discovery of luminescent materials.

Intelligent gold nanocluster for effective treatment of malignant tumor via tumor-specific photothermal-chemodynamic therapy with AIE guidance.

Precise and efficient therapy of malignant tumors is always a challenge. Herein, gold nanoclusters co-modified by aggregation-induced-emission (AIE) molecules, copper ion chelator (acylthiourea) and tumor-targeting agent (folic acid) were fabricated to perform AIE-guided and tumor-specific synergistic therapy with great spatio-temporal controllability for the targeted elimination and metastasis inhibition of malignant tumors. During therapy, the functional gold nanoclusters (AuNTF) would rapidly accumulate in the tumor tissue due to the enhanced permeability and retention effect as well as folic acid-mediated tumor targeting, which was followed by endocytosis by tumor cells. After that, the overexpressed copper ions in the tumor cells would trigger the aggregation of these intracellular AuNTF via a chelation process that not only generated the photothermal agent in situ to perform the tumor-specific photothermal therapy damaging the primary tumor, but also led to the copper deficiency of tumor cells to inhibit its metastasis. Moreover, the copper ions were reduced to cuprous ions along with the chelation, which further catalysed the excess H2O2 in the tumor cells to produce cytotoxic reactive oxygen species, resulting in additional chemodynamic therapy for enhanced antitumor efficiency. The aggregation of AuNTF also activated the AIE molecules to present fluorescence, which not only imaged the therapeutic area for real-time monitoring of this tumor-specific synergistic therapy, but also allowed us to perform near-infrared radiation at the correct time point and location to achieve optimal photothermal therapy. Both in vitro and in vivo results revealed the strong tumor elimination, effective metastasis inhibition and high survival rate of tumor-bearing mice after treatment using the AuNTF nanoclusters, indicating that this AIE-guided and tumor-specific synergistic strategy could offer a promising approach for tumor therapy.

Multi-stimuli fluorescence responsiveness of α-cyanostilbene derivative: AIEE, stimuli response to polarity, acid, force and light, applications in anti-counterfeiting and single phosphor w-OLED

Recently, the small molecule functional materials with a simple synthesis have attracted more and more attention. A multi-stimuli-responsive aggregation-induced emission (AIE) molecule is expected to have great applications in the near future. Identically, the single-component white organic light diode (w-OLED) has a good application field. Herein, a cyanostilbene derivative (TSC) was efficiently synthesized by Vilsmeier and Knoevenagel reactions with only 2 steps under mild conditions. TSC was characterized by NMR (1H, 13C), FT-IR, HRMS and elemental analysis. TSC has aggregation-induced enhanced emission (AIEE) effect, and significant polar-, acid-, force- and light-stimuli fluorescence responsiveness properties. The AIE effect and four different stimulus responses are all simultaneously presented in TSC. This phenomenon is relatively rare in small molecule fluorescent compounds. The results of SEM and DLS reveal the AIEE of TSC is mainly due to the fact that molecular self-assembly into nanofiber networks in the aggregated state limiting the distortion of molecules. DFT calculations show that the polarity stimuli-response (fluorescence from green to orange) is closely related to intramolecular charge transfer (ICT). Acid/base 1H NMR titration proves that the acidochromism results from reversible protonation/deprotonation. The results of DSC, SEM, PXRD and POM prove that the essence of mechanical force stimuli-response is the change of crystallinity. The results of 1H NMR, UV–vis and fluorescence spectra, DFT calculations and SEM reveal that the light stimuli-response is attributed to the Z/E configuration transformation. Based on multi-stimuli responsive properties, TSC can be used for recognition of solvents polarity by naked eyes or fluorophotometer, used as an acid indicator and also used to quantitatively test the concentration of trace acids, used in anti-counterfeiting including safty ink, data rewriting, even can be used to construct supramolecular liquid crystals materials. In addition, TSC can be used to fabricate single phosphor w-OLED, avoiding using multicomponent composite materials.

A one-two punch targeting reactive oxygen species and fibril for rescuing Alzheimer’s disease

Toxic amyloid-beta (Aβ) plaque and harmful inflammation are two leading symptoms of Alzheimer’s disease (AD). However, precise AD therapy is unrealizable due to the lack of dual-targeting therapy function, poor BBB penetration, and low imaging sensitivity. Here, we design a near-infrared-II aggregation-induced emission (AIE) nanotheranostic for precise AD therapy. The anti-quenching emission at 1350 nm accurately monitors the in vivo BBB penetration and specifically binding of nanotheranostic with plaques. Triggered by reactive oxygen species (ROS), two encapsulated therapeutic-type AIE molecules are controllably released to activate a self-enhanced therapy program. One specifically inhibits the Aβ fibrils formation, degrades Aβ fibrils, and prevents the reaggregation via multi-competitive interactions that are verified by computational analysis, which further alleviates the inflammation. Another effectively scavenges ROS and inflammation to remodel the cerebral redox balance and enhances the therapy effect, together reversing the neurotoxicity and achieving effective behavioral and cognitive improvements in the female AD mice model.

Dual/Multi-Modal Image-Guided Diagnosis and Therapy Based on Luminogens with Aggregation-Induced Emission.

The combination of multiple imaging methods has made an indelible contribution to the diagnosis, surgical navigation, treatment, and prognostic evaluation of various diseases. Due to the unique advantages of luminogens with aggregation-induced emission (AIE), their progress has been significant in the field of organic fluorescent contrast agents. Herein, this manuscript summarizes the recent advancements in AIE molecules as contrast agents for optical image-based dual/multi-modal imaging. We particularly focus on the exceptional properties of each material and the corresponding application in the diagnosis and treatment of diseases.

A wireless fluorescent flexible force sensor based on aggregation-induced emission doped liquid crystal elastomers.

Flexible strain sensors have drawn a lot of interest in various applications including human mobility tracking, rehabilitation/personalized health monitoring, and human-machine interaction, but suffer from interference of electromagnetic (EM). To overcome the EM interference, flexible force sensors without sensitive electronic elements have been developed, with drawbacks of bulky modules that hinders their applications in remote measurement with power-free environment. Therefore, it is highly desirable to fabricate a compact wireless flexible force sensor but it is still a challenge. Here, we demonstrate a fluorescent flexible force sensor based on aggregation-induced emission (AIE) doped liquid crystal elastomer (LCE) experimentally. The proposed force sensor film can be used to measure force through the variation of fluorescent intensity induced by the extension or contraction of LCE film, which leads to reduce or increase of the aggregation degree of AIE molecules within. This compact wireless force sensor features lightweight, low-cost, high flexibility, passivity and anti-EM interference, which also enables the naked eye observation. The proposed sensor provides inspiration and a platform for a new concept of non-contact detection, showing application potential in human-friendly interactive electronics and remote-control integration platform.

Aggregation-induced emission organic metal halide complex for X-ray scintillation.

The expanding applications of X-ray scintillation across various areas, from healthcare to security detection call for the development of new-generation scintillators that offer enhanced sensitivity, efficiency, and versatility. Here, we report for the first time the use of organic metal halide complexes with aggregation-induced emission (AIE) for X-ray scintillation, which can be facilely synthesized and processed in the solution phase. By reacting an AIE organic molecule, 4-(4-(diphenylamino) phenyl)-1-(propyl)-pyridinium (TPA-PD) with zinc chloride (ZnCl2) in solution at room temperature, an organic metal halide complex, (TPA-PD)2ZnCl2, is produced with a high synthetic yield of 87%. Optical and radioluminescence characterizations find that (TPA-PD)2ZnCl2 exhibits bluish-green photoluminescence and radioluminescence peaked at around 450 nm, with a photoluminescence quantum efficiency (PLQE) of 65%, and an absolute light yield of 13 423 Photon per MeV. Moreover, short photoluminescence and radioluminescence decay lifetimes are recorded at 1.81 ns and 5.24 ns, respectively. For X-ray scintillation, an excellent response dose-response linearity and a low limit of detection of 80.23 nGyair S-1 are obtained for (TPA-PD)2ZnCl2. By taking advantage of the high X-ray absorption of metal halides and fast radioluminescence of AIE molecules, our design of covalently bonded organic metal halide complexes opens up new opportunities for the development of high-performance solution-processable scintillators.

Construction of Multi‐Module RNA Nanoparticles Harboring miRNA, AIE, and CH6 Aptamer for Bone Targeting and Bone Anabolic Therapy

AbstractBone healing remains a major challenge in the treatment of osteoporosis. Effective strategies that simultaneously promote bone formation and inhibit bone resorption are crucial for the treatment of osteoporosis and associated bone defects. MicroRNA (miRNA)‐based approaches aim at simultaneously promoting bone formation and suppressing bone resorption and have therapeutic potential. However, the toxicity of cationic carriers and off‐target effects are two major challenges associated with miRNA delivery. This study establishes a bone‐targeting miRNA delivery system (CH6‐SNA‐26a) that integrates aggregation‐induced emission (AIE), a CH6 aptamer, and miRNAs into a single nanoplatform without any cationic carrier. In this system, an AIE molecule is coupled to miR‐26a to form a core–shell spherical nucleic acid (SNA‐26a). The CH6 aptamer is co‐assembled with the SNA to achieve specific miR‐26a delivery to the bone surface. This aptamer‐functionalized, non‐cationic miR‐26a delivery strategy (CH6‐SNA‐26a) enables both bone‐targeted delivery and high transfection efficiency, ultimately optimizing bone remodeling and calvarial bone healing in an osteoporosis mouse model while limiting adverse effects in non‐skeletal tissues. Mechanistically, the overexpression of CH6‐SNA‐26a in skeletal tissues promotes bone anabolic action by functionally targeting glycogen synthase kinase 3 beta in bone marrow mesenchymal stem cells and cellular communication network 2 in osteoclasts.

Endowing an amphiphilic aggregation-induced emission molecule with turn-on fluorescence in both latent fingerprints development and antibiotics detection

The water-soluble aggregation-induced emission (AIE) molecule is desirable as a turn-on fluorescence probe, but it is challenging because most AIE-based molecules are lipophilic and can emit strong fluorescence in water. To address the problem, tetraphenylethene (TPE) backbones are decorated with hydrophilic pyridine ethanol-related groups, and a series of novel amphiphilic TPE-based pyridinium salts (denoted as TPE-Py-OH, TPE-2Py-2OH and TPE-4Py-4OH) are synthesized. Encouragingly, TPE-2Py-2OH aqueous solution which is almost non-emissive can be used as a bifunctional turn-on fluorescent probe for developing latent fingerprints (LFPs) and detecting antibiotics. Level 3 details in LFPs are developed via soaking/ spraying method, owing to that AIE phenomenon is activated by the combination of lipophilic part in TPE-2Py-2OH and fatty acid residues in fingerprints. The method is worthy to promote, because it displays the advantages of water solubility, low working concentration, ease of operation, good stability, high safety, high contrast, high sensitivity, and high selectivity. It can also response to penicillin potassium (PNG) with a detection limit of 0.18 μM because the electrostatic interaction between TPE-2Py-2OH and PNG can mainly induce the enhanced fluorescence. This discovery provides a facile approach to design more promising amphiphilic AIE-based turn-on fluorescence probes.

Sub‐Nanoconfined Aggregation‐Induced Emission Molecules via Stacked Layers of Microtubular Covalent Organic Frameworks for Enhanced Fluorescence

AbstractFunctionalizing aggregation‐induced emission molecules (AIEs) by confining them in porous materials is attracted extensive attention. Here stacked layers of hollow microtubular covalent organic frameworks (HT‐COFs) are introduced as sub‐nanoconfined sites (0.37 nm) to confine AIEs. The spacious hollow channels allow unimpeded entry for AIEs, while the interlayers perpendicular to the channels partially incarcerate the AIEs within the COFs layers. This effectively restricts the intramolecular rotation of AIEs and facilitates its radiative processes. Through exchanging of various AIEs, the versatility of the COFs interlayer as a restriction site is demonstrated. Furthermore, the sub‐nanoconfined fluorescence in AIEs@HT‐COFs displays reversible temperature dependence. Based on this, a temperature‐tunable fluorescent Micro‐QR code device is fabricated, wherein the encoded information disappears at a high‐temperature and reemerges at a low‐temperature. This work offers novel insights into confined fluorescence within functional materials and the fabrication of AIEs‐COF multiplex frameworks.

A simple AIE probe to pesticide trifluralin residues in aqueous phase: Ultra-fast response, high sensitivity, and quantitative detection utilizing a portable platform

The threat from pesticide trifluralin residues to ecological environment and public health is becoming a growing problem. Thus, rapid and sensitive detection, particularly a simple and portable detected platform for trifluralin residues, are highly desired. Here, a small organic aggregation-induced emission (AIE) molecule (TPETPy) is facilely synthesized and applied to detect trifluralin both in lab and in actual water systems. Based on the photo-induced electron transfer (PET) mechanism, the emissive peak of TPETPy located at 475 nm in tetrahydrofuran (THF)/water mixture (ƒw = 90 %) under the excitation of 340 nm, decreases dramatically upon trace trifluralin addition and exhibits ultra-fast response (3 s), high sensitivity and selectivity, and good anti-interference ability. The fluorescence sensing correlation with the concentration of trifluralin shows good linearity in the range of 20–90 μg L−1 with the limit of detection of 6.28 μg L−1. Moreover, a portable smartphone-integrated detected platform based on fluorescent pattern Red/Green/Blue (RGB) values is first employed to realize the real-time and on-site quantitative fluorescent detection of trifluralin in actual water sources, featuring good accuracy and reproducibility. Hereby, this work provides not only a highly efficient trifluralin residues fluorescent probe but also a portable and straightforward operating platform to detect trifluralin pesticides quantitatively.

TPE conjugated islet amyloid polypeptide probe for detection of peptide oligomers

Islet amyloid polypeptide (IAPP), also known as amylin, is a polypeptide hormone co-secreted with insulin by pancreatic β-cells. In general, IAPP is soluble and lacks a defined structure. However, under certain conditions, these peptides tend to aggregate into soluble oligomers, eventually forming insoluble amyloid fibrils with typical cross-β-sheet structures. Amylin aggregates, therefore, have been regarded as one of the hallmarks of type II diabetes (T2D). Among these aggregated species, oligomers were shown to exhibit significant cytotoxicity, leading to impaired β-cell function and reduced β-cell mass. Monitoring of oligomer appearance during IAPP fibrillation is of particular interest. In this study, we successfully grafted an aggregation-induced emission molecule, tetraphenylethylene (TPE), at the N-terminus of IAPP. By mixing a small amount of TPE-labeled IAPP with unlabeled IAPP, we were able to detect an increase in TPE fluorescence during the nucleation phase of IAPP aggregation in vitro. It may enable real-time monitoring of IAPP oligomer formation and is further applied in the diagnosis of T2D.