Chen Gui

A Mitochondrion-Specific Photoactivatable Fluorescence Turn-On AIE-Based Bioprobe for Localization Super-Resolution Microscope

A novel mitochondrion-specific photo-activatable fluorescence turn-on bioprobe, named as o-TPE-ON+, is designed and readily prepared, operating through a new photoactivatable mechanism of photocyclodehydrogenation. This bioprobe exhibits unique photoactivation behavior in cells, and is applied to super-resolution imaging of mitochondrion and its dynamic investigation in both fixed and live cells under physiological conditions without any external additives.

A Luminogen with Aggregation-Induced Emission Characteristics for Wash-Free Bacterial Imaging, High-Throughput Antibiotics Screening and Bacterial Susceptibility Evaluation.

A luminogen with aggregation-induced emission characteristics is reported for bacterial imaging and antibiotics screening studies. The luminogen can light up bacteria in a wash-free manner, which simplifies the imaging process and increases its accuracy in bacterial detection. It can also be applied to high-throughput screening of antibiotics and fast evaluation of bacterial susceptibility, giving reliable results in less than 5 h.

A simple mitochondrial targeting AIEgen for image-guided two-photon excited photodynamic therapy

Two-photon excited photodynamic therapy (TP-PDT) is not only able to offer deeper penetration depth but also much more precise 3D treatment than traditional one-photon excited PDT. However, the achievement of TP-PDT requires photosensitizers with large two-photon absorption cross sections, efficient generation of reactive oxygen species, and bright two-photon fluorescence. In this work, we present a simple AIE luminogen (AIEgen), IQ-TPA, with mitochondrial targeting and susceptible two-photon excitation for image-guided photodynamic therapy in cancer cells. This feasibility of utilizing small molecular multifunctional AIEgens for TP-PDT was demonstrated together with the merits of tiny size, good cell permeability, low dark cytotoxicity and easy synthesis, showing great potential for the development of future theranostic systems.

Thermally activated delayed fluorescence material with aggregation-induced emission properties for highly efficient organic light-emitting diodes

Luminescent materials with aggregation-induced emission (AIE) properties exhibit high solid state emission, while thermally activated delayed fluorescence (TADF) materials can fully harvest singlet and triplet excitons to achieve efficient electroluminescence (EL). Herein, the amalgamation of AIE and TADF properties, termed aggregation-induced emission and thermally activated delayed fluorescence (AIE–TADF), is a promising strategy to design novel desirable luminescent materials. In this paper, a new tailor-made material, DCPDAPM, is obtained based on carbazole as the skeleton, 9,9-dimethyl-9,10-dihydroacridine as the donor group and benzophenone as the acceptor group. Its structure is fully characterized by elemental analysis, NMR spectroscopy and mass spectrometry. Furthermore, its thermal stability, photophysical properties, and electrochemical properties are investigated systematically. The results show that this AIE–TADF compound exhibits good thermal stability, electrochemical stability and AIE and TADF properties. Ultimately, using DCPDAPM and DCPDAPM doped into CBP as light-emitting layers, a non-doped OLED (device A) and doped OLEDs (device B, device C and device D) were fabricated and studied. Device A displays green light with a turn-on voltage of 3.2 V, a maximum brightness of 123 371 cd m−2, a maximum current efficiency of 26.88 cd A−1, a maximum power efficiency of 15.63 lm W−1 and an external quantum efficiency of 8.15%. Among the doped OLEDs (device B, device C and device D), device D shows the best EL performance with a turn-on voltage of 3.6 V, a maximum brightness of 116 100 cd m−2, a maximum current efficiency of 61.83 cd A−1, a maximum power efficiency of 40.45 lm W−1 and an external quantum efficiency of 19.67%. These results adequately demonstrate the practicability of combining AIE and TADF to explore new efficient emitters.

Functional isocoumarin-containing polymers synthesized by rhodium-catalyzed oxidative polycoupling of aryl diacid and internal diyne

An atom-economical and straightforward polymerization method to generate functional isocoumarin-containing polymers was developed in this work. The oxidative polycoupling of 4,4′-(1,2-diphenyl-1,2-ethenylene)dibenzoic acid and 1,6-bis[4-(phenylethynyl)phenoxy]hexane proceeds efficiently in dimethylformamide under nitrogen or air in the presence of [Cp*RhCl2]2 and a catalytic amount of Cu(OAc)2·H2O at 120 °C for 24 h, generating a polymer with a high molecular weight of up to 42 900 in a high yield of up to 92.9%. An isocoumarin framework forms in situ during the polymerization from readily accessible and inexpensive monomers. The resulting polymer possesses good thermal stability, optical transparency and film-forming ability. Its thin film exhibits high and UV-tunable refractive indices (n = 1.9697–1.6507) in a wide wavelength region of 390–890 nm. A two-dimensional fluorescent photopattern can be readily fabricated by irradiating its thin film under UV light through a copper mask. Due to the incorporation of tetraphenylethene units in the monomer, the polymer obtained is weakly emissive in solution but it emits intensely when aggregated, demonstrating a phenomenon of aggregation-induced emission.

Synthesis, aggregation-induced emission and electroluminescence properties of three new phenylethylene derivatives comprising carbazole and (dimesitylboranyl)phenyl groups

It is essential that light-emitting materials possess high fluorescence intensity in the solid-state and a stable charge-transporting ability for the construction of organic light-emitting diodes (OLEDs) with outstanding performance. In this paper, three phenylethene derivatives, 3-(4-(dimesitylboryl)phenyl)-6-(1,2,2-triphenylvinyl)-9-ethyl-9H-carbazole (DBPTECZ), 3-(4-(dimesitylboryl)phenyl)-6-(1,2-diphenylvinyl)-9-ethyl-9H-carbazole (DBPDPECZ) and 3-(1-(4′-(dimesitylboryl)-[1,1′-biphenyl]-4-yl)-2-phenylvinyl)-9-ethyl-9H-carbazole (DBBPPECZ) with a hole-transporting group (carbazole) and an electron-transporting group ((dimesitylboranyl)phenyl group), are synthesized and sufficiently characterized using elemental analysis, and 1H NMR, 13C NMR and mass spectrometry. All three compounds show typical AIE features with strong solid-state fluorescence. Besides, they also possess good thermal stabilities with Td of 219 °C, 188 °C and 167 °C respectively. Furthermore, non-doped OLED devices employing DBPTECZ, DBPDPECZ, and DBBPPECZ as functional layers are fabricated, showing remarkable performance with blue-green, deep blue and sky blue emissions, respectively. The Lmax values of the three molecules reach up to 21 054 cd m−2, 4376 cd m−2 and 12 080 cd m−2, and ηC,max are 3.34 cd A−1, 2.34 cd A−1 and 1.73 cd A−1, respectively. These results demonstrate that the present compounds are promising candidates for OLEDs.

Selective and sensitive fluorescent probes for metal ions based on AIE dots in aqueous media

Multi-functional fluorescent probes have attracted more interest recently. Herein, two simple fluorescent probes (FAS and DPAS) from AIEgens with the ESIPT process of salicylaldehyde Schiff-base structures are developed. The aggregates of FAS and DPAS exhibit good selectivity and sensitivity towards Cu2+ in aqueous media without any water-miscible organic solutions as buffers. Their larger association constants and appropriate hydrophilic and hydrophobic properties play key roles in achieving lower detection limits. Based on their fluorescence on/off processes in the presence or absence of Hg2+, the composite probes are further prepared.

A fluorescent sensor array for highly efficient microbial lysates identification through competitive interactions

Optical cross-reactive sensor arrays have recently been proven to be a powerful tool for high-throughput bioanalytes identification. Nevertheless, identification and classification of microbes, especially using microbial lysates as the analytes, still is a great challenge due to their complex composition. Herein, we achieve this goal by using luminogens featuring aggregation-induced emission characteristics (AIEgens) and graphene oxide (GO) to construct a microbial lysate responsive fluorescent sensor array. The combination of AIEgen with GO not only reduces the background signal but also induces the competition interactions among AIEgen, microbial lysates, and GO, which highly improves the discrimination ability of the sensor array. As a result, six microbes, including two fungi, two Gram-positive bacteria, and two Gram-negative bacteria are precisely identified. Thus, this work provides a new way to design safer and simpler sensor arrays for the discrimination of complex analytes.