TPE Derivative Research Articles

Dual emitting aggregation-induced electrochemiluminescence from tetrastyrene derivative for chloramphenicol detection

Chloramphenicol (CAP) poses a threat to human health due to its toxicity and bioaccumulation, and it is very important to measure it accurately and sensitively. This work explored a host-guest recognition strategy to mediate dual aggregation-induced electrochemiluminescence (AIECL) of 1,1,2,2-tetrakis(4-(pyridin-4-yl) phenyl)-ethene (TPPE) for ratio detection of CAP, in which, cucurbit[8]uril (CB[8]) served as host to assemble guest TPPE. The resulting supramolecular complex CB[8]-TPPE exhibited excellent dual-AIECL-emission with signal strength approximately four times that of TPPE aggregates and black hole quencher-1 (BHQ1) could efficiently quench dual-AIECL signal. CB[8]-TPPE coupled dual-function quencher BHQ1 and high-efficiency DNA reactor to achieve ultra-sensitive detection of CAP, exhibiting a linearity range of 10 fmol·L−1–100 nmol·L−1 and limit of detection of 1.81 fmol·L−1. CB[8]-TPPE provides a novel way to improve the dual-emission of TPE derivatives and sets up a promising platform for CAP detection, demonstrating a good practical application potential.

Codelivery of CPT and siPHB1 with GSH/ROS Dual-Responsive Hybrid Nanoparticles Based on a [12]aneN3-Derived Lipid for Synergistic Lung Cancer Therapy.

The combination of small-interfering RNA (siRNA)-mediated gene silencing and chemotherapeutic agents for lung cancer treatment has attracted widespread attention in terms of a greater therapeutic effect, minimization of systemic toxicity, and inhibition of multiple drug resistance (MDR). In this work, three amphiphiles, CBN1-CBN3, were first designed and synthesized as a camptothecin (CPT) conjugate and gene condensation agents by the combination of CPT prodrugs and di(triazole-[12]aneN3) through the ROS-responsive phenylborate ester and different lengths of alkyl chains (with 6, 9, 12 carbon chains for CBN1-CBN3, respectively). CBN1-CBN3 were able to be self-assembled into liposomes with an average diameter in the range of 320-240 nm, showing the ability to effectively condense siRNA. Among them, CBN2, with a nine-carbon alkyl chain, displayed the best anticancer efficiency in A549 cells. In order to give nanomedicines a stealth property and PEGylation/dePEGylation transition, a GSH-responsive PEGylated TPE derivative containing a disulfide linkage (TSP) was further designed and prepared. A combination of CBN2/siRNA complexes and DOPE with TSP resulted in GSH/ROS dual-responsive lipid-polymer hybrid nanoparticles (CBN2-DP/siRNA NPs). In present GSH and H2O2, CBN2-DP/siRNA NPs were decomposed, resulting in the controlled release of CPT drug and siRNA. In vitro, CBN2-DP/siPHB1 NPs showed the best anticancer activity for suppression of about 75% of A549 cell proliferation in a serum medium. The stability of CBN2-DP/siRNA NPs was significantly prolonged in blood circulation, and they showed effective accumulation in the A549 tumor site through an enhanced permeability and retention (EPR) effect. In vivo, CBN2-DP/siPHB1 NPs demonstrated enhanced synergistic cancer therapy efficacy and tumor inhibition as high as 71.2%. This work provided a strategy for preparing lipid-polymer hybrid NPs with GSH/ROS dual-responsive properties and an intriguing method for lung cancer therapy.

A luminescent supramolecular polymer based on a stiff-stilbene bridged pillar[5]arene as a Pd2+-responsive smart material

A luminescent supramolecular polymer based on a novel stiff-stilbene bridged pillar[5]arene and a TPE derivative, serving as a Pd2+ responsive smart material.

Polymorphism and Light-Driven Forward Movement of TPE Derivative Micro-Crystal due to ArH-pi Interactions Difference.

Aggregation-induced emission (AIE) and aggregation-caused quenching (ACQ) are two classes of opposite luminescence phenomena. It is almost impossible to show both AIE and ACQ effect simultaneously by the same molecule. However, here we report that a simple TPE derivative TAP-TPE grows into both AIE crystals and ACQ ones. It is found that equatorial, contact distance-longer and weak ArH-π interactions exist in AIE crystals while vertical, contact distance-shorter and strong ArH-π interactions appear in ACQ crystals. Theoretical calculation of electron density on the interaction atoms unveils that ACQ crystals have much larger change in electron density than AIE ones, suggesting that the intermolecular electron transfer aroused by the strong ArH-π hydrogen bonds leads to ACQ phenomenon. This result provides a new insight into the emission mechanism in aggregation state. Interestingly, due to the ArH-pi interactions difference, only one of five kinds of crystals shows rapid photochromism, and can act as multimode anti-counterfeiting materials. Very exceptionally, for the first time we find that the photochromic micrometric rod-like crystal even makes forward rolling movement as it repeatedly bends and straightens by responding to on and off of the ultraviolet light irradiation, displaying potential for photo-actuator and light-driven micro-vehicle.

Label‐Free Fluorescence Turn‐On Detection of Histidine‐Tagged Proteins Based on Intramolecular Rigidification Induced Emission

AbstractHistidine tag (His‐tag) is a representative epitope tag, which has been widely used in the purification or immobilization of recombinant proteins. In this study, a novel probe CTPE‐IDA‐Ni2+ based on intramolecular rigidification induced emission for fluorescence detecting His‐tagged proteins is successfully developed and experimentally demonstrated. This detecting system is based on TPE derivative incorporated IDA‐Ni2+ moiety for real‐time detection of His‐tagged proteins. In the presence of His‐tagged proteins, the IDA‐Ni2+‐His‐tag complex was formed, which restricted the rotation of two phenyl rings linked with TPE and subsequently resulting in the fluorescence turn on. Results have shown that our probe could directly detect His‐tagged proteins with good selectivity and fast response within 10 min. In addition, we have proved that this system could be used in fluorescent labeling of His‐tagged protein instead of traditional Western blot assay with simple procedure, high quality and low background interference, as well as without aggregation‐caused quenching (ACQ) problems like some organic dyes.

A Smart Molecule Showing Spin Crossover Responsive Aggregation-Induced Emission

A Smart Molecule Showing Spin Crossover Responsive Aggregation-Induced Emission

Multiple stimulus responsive Co-AIE framework materials with reversible solvatochromic and thermochromic behaviors: molecular design, synthesis and characterization

A novel Co-AIE-MOF (Co-tcbpe) based on TPE derivatives is designed and synthesized. And it shows a multi-stimuli response in the application of reversible solvatochromism and thermochromism.

Color-tuning and manipulation of the aggregation-induced emission efficiency of o-carborane-tetraphenylethylene dyads through substituted o-carboranes

By changing the 2-R substituents of carborane, absolute solid state fluorescence quantum yields of TPE derivatives ranging from 18% to 91% were obtained. The emission colors show a clear shift from blue to red with a maximum red shift of 239 nm.

AIEgens with cyano-modification in different sites: Potential ‘Meta-site effect’ in mechanochromism behavior

The current research of mechanochromic molecules focused on different molecular skeletons and the types of functional groups, where the design ideas were limited. We have synthesized a group of cyano-modified TPE derivatives (TPECN) with different substitution sites, showing typical aggregation induced emission (AIE) effect. We found that meta-substituted mCN revealed the inertness of mechanochromism, whether being ball milled or rapidly evaporated. Isomers with ortho- or para-substitution showed an emission wavelength shift over 40 nm. Experimental data indicated unusual high-strength lattice stability for mCN. By single-crystal analysis and theoretical calculations, we clarified from the molecular skeleton distortion, noncovalent intermolecular interactions, and calculated interaction energy that the meta-substitution led to a stable lattice structure, making mCN insensitive to external stimuli. Thus, we successfully explained the substituted site was an important and independent factor that influenced the mechanochromic property. Meanwhile, we also explored the application of the TPECNs series for erasable printing and coding.

Facile construction of aggregation-induced emission molecular liquids via Piers-Rubinsztajn reaction for green fluorescent ink

Solvent-free luminescent molecular liquids (LMLs), which exhibit nonvolatile fluidic nature and active optoelectronic properties, were widely used. For further development, we introduced siloxane units into AIE molecules, designed and synthesized TPE derivatives with siloxane side chains via facile Piers-Rubinsztajn reaction. The obtained AIE molecular liquids exhibit unique photophysical properties. Compared with the obtained alkyl TPE-solids, siloxane TPE show liquid state, which proves that the siloxane units have stronger liquefaction effect than alkyl. Viscosity test shows that siloxane TPE-liquids has far more lower viscosity and better fluidity than the long-chain alkyl molecular liquids in previous research. All those properties are attributed to the weak interaction between flexible molecular chains of siloxane. Besides, fluorescence test shows temperature responsiveness of siloxane TPE-liquids. We developed this low-viscosity nonvolatile AIE molecular liquid as green fluorescent ink.

A tetraphenylethylene derivative with reversible luminous colours applied in data security

Exploration of the relationship between molecular structure and properties of materials, particularly the multi-stimuli-responsive types, remain a challenge. Herein, we designed, synthesized and tested the photo-physical properties of a multi-stimuli-responsive TPE derivative (TPE-(C3Br)4). The TPE-(C3Br)4 exhibits piezochromic emitting deep-blue to green-blue light under external grinding. Interestingly, both non-ground and ground TPE-(C3Br)4 exhibits vapochromic and thermochromic properties. When exposed to CH2Cl2 vapor for 3 min and thereafter heated at 90 °C for 5 min or heat at 140 °C for 3 min and exposed to CH2Cl2 vapor for 2 s, TPE-(C3Br)4 reversibly glows between deep-blue and green-blue. The ground sample glows between green-blue and deep-blue under only one stimulus for a few min (e.g. heating or fuming alone). The multi-stimuli-responsive properties of TPE-(C3Br)4 are attributed to variation in intermolecular stacking and intramolecular twisting. The TPE-(C3Br)4 was used to develop a new encryption-decryption method. These findings demonstrate the utility of smart responsive TPE-(C3Br)4 material in developing data protection systems.

A multi-stimuli responsive tetraphenylethene derivative: Self-reversible mechanochromism, mechanoluminescence, switchable photochromism

Most of the reported stimuli-responsive aggregation induced emission (AIE) molecules are single-functioned and it remains highly demanded to integrate multi-stimuli responsive properties in one molecule. A multi-stimuli responsive TPE derivative 1 was synthesized bearing multiple properties including mechanochromism, mechanoluminescence and photochromism. Mechanoluminescence was only shown by the single crystal form, while photochromism was only observed in the amorphous powder. The mechanochromic property of 1 was self-reversible, but can also be accelerated by thermal or solvent vapor treatment. The photochromic property of 1 was easily switched on by a phase transition from crystalline state to amorphous state upon grinding. By a combination of mechanochromism and photochromism, a two-step procedure of color response of 1 was demonstrated upon grinding and UV irradiation. This novel molecule provides an important insight to the development of multi-stimuli responsive materials and advanced anti-counterfeiting materials.

A ratiometric fluorescence sensor based on enzymatically activatable micellization of TPE derivatives for quantitative detection of alkaline phosphatase activity in serum.

A novel ratiometric fluorescence assay via enzymatically activatable micellization in aqueous solution was devised for quantitative detection of alkaline phosphatase (ALP) activity. We demonstrated that the dephosphorylation of the water-soluble, phosphate-functionalized, fluorophore monomer P-TPE-TG, induced by an enzymatic reaction of ALP, leads to micelle formation in aqueous solution because its water-soluble functionality is reduced. The dephosphorylation-induced micellization of P-TPE-TG exhibited a ratiometric sensing response for various ALP concentrations (10–200 mU mL−1) and provided a suitable sensing platform for naked eye detection with increased fluorescence quantum yield (Φ = 3.2%), even compared to a typical TPE-based sensor (Φ = 1.0%), where ALP can be sensed with a detection limit of 0.034 mU mL−1. In addition, P-TPE-TG displayed excellent sensing performance at concentrations from 0 to 50 mU mL−1 in diluted human serum (10%), which offers the capability to exploit ratiometric responses for bioactive substances under practical conditions.

Thiophene-containing tetraphenylethene derivatives with different aggregation-induced emission (AIE) and mechanofluorochromic characteristics.

Four thiophene-containing tetraphenylethene derivatives were successfully synthesized and characterized. All these highly fluorescent compounds showed typical aggregation-induced emission (AIE) characteristics and emitted different fluorescence colors including blue-green, green, yellow and orange in the aggregation state. In addition, these luminogens also exhibited various mechanofluorochromic phenomena.

Controllable synthesis and AIE properties of fluorescent polyesters

For the potential application of functional polyesters in biomedical field, a series of side-chain functional fluorescent polyesters have been designed and prepared through the polymerization of AIE-functionalized carbonate monomer TPETC. The controllable nature of TPETC’s ROP and ROCP using different organocatalysts has been proved. In the dilute solution of these AIE polyesters, the structure of the polymers themselves, concentration of the polymer solution and other external conditions would obviously affect the aggregation of the side groups (TPE derivatives), and thus affecting the AIE phenomenon of the polymers. The structure of polymer chain had certain influences to the distribution and movements of side-groups, and these influences were reflected by the fluorescence intensity here. It is expected that this conclusion would provide a new perspective for the inner characteristics of dilute polymer solutions and broaden the application of AIE macromolecules.

A New Thermo‐, pH‐ and CO2‐Responsive Fluorescent Four‐Arm Star Polymer with Aggregation‐Induced Emission for Long‐Term Cellular Tracing

AbstractDevelopment of fluorescent bioprobes for long‐term cell tracking is of great importance to monitor the processes of genesis, development, invasion, and metastasis of cancerous cells. Herein, a new multistimuli‐responsive star polymer of tetraphenylethene‐graft‐tetra‐poly[N‐[2‐(diethylamino)‐ethyl]acrylamide] (TPE‐tetraPDEAEAM) with aggregation‐induced emission (AIE) effect for tracing live cells over a long period of time is synthesized by atom transfer radical polymerization using TPE derivative as initiator. TPE‐tetraPDEAEAM gives both lower critical solution temperature and fluorescence responses to the stimulus of the temperature, pH, and CO2 by combining the thermoresponsive and pH/CO2‐responsive moieties of the diethylamino and acrylamide groups. The AIE‐active TPE‐tetraPDEAEAM has the advantages of very low cytotoxicity, efficient cellular uptake, and strong fluorescence of polymer‐treated cells, which ensure its good performance in long‐term cell tracing. This facile tracking of HeLa cells for as long as nine passages exhibits superior performance in long‐term cell tracing as compared with some commercial cell tracing probes.

Regulating the emission of tetraphenylethenes by changing the alkoxyl linkage length between two neighboring phenyl moieties.

Alkoxyl linkages with different carbon lengths are employed to link the two neighboring ortho carbons of the two phenyl moieties at the same ethylene carbon of the tetraphenylethene framework, resulting in successful regulation of the molecular conformation and in turn the emission properties.

PH-Dependent self-assembly of water-soluble sulfonate-tetraphenylethylene with aggregation-induced emission

The fabrication of well-defined nanostructures with luminescent properties in the solid or aggregated state is of intense interest due to their applications in nano- and biotechnology. We report the synthesis of water-soluble tetraphenylethylene bearing four sulfonate groups as a sodium salt (Su-TPE), and investigations concerning its AIE characteristics by the addition of organic solvent into the aqueous solution, which is the reverse procedure to conventional AIE-active TPE derivatives. The resultant compound is weakly emissive in pure water, however, emits strongly upon addition of THF solvent (with THF fraction > 60%). The emission properties and the morphologies of the aggregates were greatly dependent upon the solution pH. Su-TPE self-assembled into variety of structures in water/THF mixture with pH control, for the first time. Well-defined uniform nanorods with a width of about 200 nm and a length of up to 10 μm were obtained at solution pH of 1. The Su-TPE showed very good mechanochromic properties were observed during the process of grounding and fuming.

Tetraphenylethylene derivative capped CH3NH3PbBr3 nanocrystals: AIE-activated assembly into superstructures.

The surfaces of semiconductor nanocrystals have been known to be a very important factor in determining their optical properties. The introduction of functionalized ligands can further enhance the interactions between nanocrystals, which is beneficial for the assembly of nanocrystals. In a previous report, we developed a ligand-assisted reprecipitation method to fabricate organometal halide perovskite nanocrystals capped with octylamine and oleic acid. Here, a TPE derivative 3-(4-(1,2,2-triphenylvinyl)phenoxy)propan-1-amine, which shows a typical aggregation induced emission feature, is applied to replace octylamine to fabricate CH3NH3PbBr3 nanocrystals. The obtained CH3NH3PbBr3 nanocrystals were nanocubes (average diameter ∼ 11.1 nm) and are likely to assemble into ordered superstructures. By adjusting the chain length of the TPE derivative, we found that the assembly of the CH3NH3PbBr3 nanocrystals was correlated with the interactions between the TPE groups. This provides a new platform to investigate the ligand effects in nanocrystal solids and may potentially achieve enhanced optical and electrical properties.

Sky-blue nondoped OLEDs based on new AIEgens: ultrahigh brightness, remarkable efficiency and low efficiency roll-off

Nondoped OLEDs based on a 4-(dimesitylboryl)fluorenyl functionalized TPE derivative show sky-blue electroluminescence, remarkable efficiencies, ultrahigh brightness and low efficiency roll-off.