Construction of a novel near-infrared fluorescent Nile blue@MOF nanoprobe for imaging mitochondrial ATP in living cells.

A near-infrared fluorescent nanoprobe consisting of Nile blue-capped ZIF-90 is first proposed for real-time imaging of mitochondrial ATP. Owing to the strong binding of ATP with Zn2+, the structure of the probe is disrupted, leading to the release of fluorescent NB.

MOF-mediated dual energy transfer nanoprobe integrated with exonuclease III amplification strategy for highly sensitive detection of DNA.

Accurate quantitative detection of DNA is an advanced strategy in various fields (such as disease diagnosis and environmental monitoring), but the classical DNA detection method usually suffers from low sensitivity, expensive thermal cyclers, or strict annealing conditions. Herein, a MOF-ERA platform for ultrasensitive HBV-DNA detection is constructed by integrating metal-organic framework (MOF)-mediated double energy transfer nanoprobe with exonuclease III (Exo III)-assisted target recycling amplification. The proposed double energy transfer containing a donor and two receptors is simply composed of MOFs (UiO-66-NH2, a well-studied MOF) modified with a signal probe formed by the hybridization of carboxyuorescein (FAM)-labeled DNA (FDNA) and black hole quencher (BHQ1)-terminated DNA (QDNA), resulting in low fluorescence signal. After the addition of HBV-DNA, Exo III degradation to FDNA is activated, leading to the liberation of the numerous FAM molecules, followed by the generation of a significant fluorescence signal owing to the negligible binding of MOFs with free FAM molecules. The results certify that the MOF-ERA platform can be successfully used to assay HBV-DNA in the range of 1.0-25.0 nM with a detection limit of 97.2 pM, which is lower than that without BHQ1 or Exo III. The proposed method with the superiorities of low background signal and high selectivity holds promise for early disease diagnosis and clinical biomedicine applications.

Electrochemical Synthesis of Cyclic Diaryl Phosphinamides via Intramolecular sp2 C-H Phosphinamidation.

We developed an oxidant- and transition-metal-free approach to construct six-membered cyclic phosphinamides via an intramolecular electrochemical C-H phosphinamidation process. With nBu4NBr as the catalyst and electrolyte, cyclic phosphinamides bearing a variety of functional groups (22 examples) were readily accessed under mild conditions. Meanwhile, this protocol provided an alternative route to organic electroluminescent materials and P-N ligands.

Electrochemical Arylation of Aldehydes, Ketones, and Alcohols: from Cathodic Reduction to Convergent Paired Electrolysis.

Arylation of carbonyls, one of the most common approaches toward alcohols, has received tremendous attention, as alcohols are important feedstocks and building blocks in organic synthesis. Despite great progress, there is still a great gap to develop an ideal arylation method featuring mild conditions, good functional group tolerance, and readily available starting materials. We now show that electrochemical arylation can fill the gap. By taking advantage of synthetic electrochemistry, commercially available aldehydes (ketones) and benzylic alcohols can be readily arylated to provide a general and scalable access to structurally diverse alcohols (97 examples, >10 gram-scale). More importantly, convergent paired electrolysis, the ideal but challenging electrochemical technology, was employed to transform low-value alcohols into more useful alcohols. Detailed mechanism study suggests that two plausible pathways are involved in the redox neutral α-arylation of benzylic alcohols.

A Bifunctional Ligand Enables Gold-Catalyzed Hydroarylation of Terminal Alkynes under Soft Reaction Conditions.

An efficient gold-catalyzed hydroarylation of alkynes under soft reaction conditions is developed by utilizing a bifunctional ligand. This transformation features a broad substrate scope and thus exhibits moderate to excellent efficiency.

A fluorescent and colorimetric probe based on naphthalene diimide and its high sensitivity towards copper ions when used as test strips.

Herein, a red fluorescent and colorimetric probe (NDI-Py) based on naphthalene diimide was designed and synthesized, which exhibited rapid response, high sensitivity and selectivity towards copper ions, and the detection limit was as low as 0.97 µM in solution. Furthermore, NDI-Py demonstrated a strong red emission in the aggregated state because of its non-planar structure. Thus, it can act as a test strip to conveniently monitor copper ions with the detection limit as low as 2.0 µM.

Tunable Aggregation-Induced Emission Nanoparticles by Varying Isolation Groups in Perylene Diimide Derivatives and Application in Three-Photon Fluorescence Bioimaging.

The development of fluorogens with deep-red emission is one of the hottest topics of investigation in the field of bio/chemosensors and bioimaging. Herein, the tunable fluorescence of perylene diimide (PDI) derivatives was achieved by the incorporation of varied isolation groups linked on the PDI core. With the enlarged sizes of isolation groups, the conversion from aggregation caused quenching to aggregation-induced emission was obtained in their fluorescence variations from solutions to nanoparticles, as the result of the efficient inhibition of π-π stacking by the larger isolation groups. Accordingly, DCzPDI bearing 1,3-di(9H-carbazol-9-yl)benzene as the biggest isolation group exhibited the bright deep-red emission in the aggregated state with a quantum yield of 12.3%. Combined with the three-photon excited fluorescence microscopy (3PFM) technology, through-skull 3PFM imaging of mouse cerebral vasculature can be realized by DCzPDI nanoparticles with good biocompatibility, and the penetration depth can be as deep as 450 µm.

New perylene diimide derivatives: stable red emission, adjustable property from ACQ to AIE, and good device performance with an EQE value of 4.93.

Perylene diimide (PDI) derivatives, due to their special opto-electronic property, have been successfully utilized in organic field-effect transistor (OFET), solar cells, and as non-fullerene acceptor and others, while few cases in organic light-emitting diodes (OLEDs). In this work, six perylene bisimide-based red emitters, N,N'-bis(2-decyltetradecyl)-1-([1,1':3',1″-terphenyl]-5'-yl)perylene-3,4,9,10-diimide (STPH), N,N'-bis(2-decyltetradecyl)-1,7-bis([1,1':3',1″-terphenyl]-5'-yl)perylene-3,4,9,10-diimide (DTPH), N,N'-bis(2-decyltetradecyl)-1-(5'-phenyl-[1,1':3',1″-terphenyl]-4-yl)perylene-3,4,9,10-diimide (STRPH), N,N'-bis(2-decyltetradecyl)-1,7-bis(5'-phenyl-[1,1':3',1″-terphenyl]-4-yl)perylene-3,4,9,10-diimide (DTRPH), N,N'-bis(2-decyltetradecyl)-1-(4-(2,2-diphenylvinyl)phenyl)perylene-3,4,9,10-diimide (STTPE) and N,N'-bis(2-decyltetradecyl)-1,7-bis(4-(2,2-diphenylvinyl)phenyl)perylene-3,4,9,10-diimide (DTTPE), with the excellent chemical, thermal and photo-chemical stability, are synthesized through the convenient Suzuki coupling reaction, in which, the fluorescent properties can be modified easily from ACQ to AIE by just simply changing the bulky volume of the introduced aromatic substituents. After being fabricated into organic light-emitting diodes, STRPH exhibits the best performance with the maximum luminescence, power efficiency, current efficiency and external quantum efficiency of 1,948 cd m-2, 2.04 lm W-1, 5.85 cd A-1, 4.93% at Commission Internationale de L'Eclairage (CIE) coordinates of (0.56, 0.34), as the result of the high efficient energy transfer and good energy match achieved in the device.

Colorimetric and fluorescent probes for real-time naked eye sensing of copper ion in solution and on paper substrate.

In this paper, BT ((E)-2-(4-(4-(bis(pyridin-2-ylmethyl)amino)styryl)-3-cyano-5,5-dimethylfuran-2(5H)-ylidene)malononitrile) with strong donor-π-acceptor structure was synthesized, which showed both colorimetric and fluorescent sensing ability toward Cu2+ with high selectivity and sensitivity. Job plot and mass spectra measurement revealed a 1 : 1 coordination mode between Cu2+ and probe BT in ethanol/HEPES (1 : 4 v/v) buffer (pH 7.2) solution, and the binding constant was calculated to be 3.6 × 104 M-1. The colour of BT solution (10 µM) immediately turned from purple red to yellow and the red fluorescence was quenched obviously when a certain amount of Cu2+ was added, which enabled a dual-channel detection of Cu2+. A paper strip pre-stained with BT solution was further fabricated and it also showed excellent sensing ability toward Cu2+ with a detection limit as low as 10-6 M with the naked eye, which represents better portability and operation simplicity that is favourable for on-site analysis of Cu2+ in water.

From ACQ to AIE: the suppression of the strong π-π interaction of naphthalene diimide derivatives through the adjustment of their flexible chains.

Unlike normal ACQ-to-AIE conversion by the introduction of aromatic rotors accompanying the realization of a twisted conformation and a prolonged π-system, in this communication, the adjustment of the flexible chains can reach this point with the tunable packing modes while the original π-system core and related properties of the aromatic naphthalene diimide remain nearly unchanged, providing an alternative approach for the inhibition of unwanted π-π stacking.