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We report a water-soluble AIEgen (TPAL) that can self-assemble into fluorescent organic nanoparticles for the ratiometric detection of mitochondrial DNA (mtDNA) parallel G-quadruplexes (G4s) with high selectivity, a low detection limit and photodynamic therapy (PDT) potential. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD), an amyloid-related disease, seriously endangers the health of elderly individuals. According to current research, its main pathogenic factor is the amyloid protein, which is a kind of fibrillar aggregate formed by noncovalent self-assembly of proteins. Based on the characteristics of aggregation-induced emission (AIE), a bislactosyl-decorated tetraphenylethylene (TPE) molecule TMNL (TPE + malononitrile + lactose), bearing two malononitrile substituents, was designed and synthesized in this work. The amphiphilic TMNL could self-assemble into fluorescent organic nanoparticles (FONs) with near-infrared (NIR) fluorescence emission in physiological PBS (phosphate buffered saline), achieving excellent fluorescent enhancement (47-fold) upon its combination with Aβ1–42 fibrils. TMNL was successfully applied to image Aβ1–42 plaques in the brain tissue of AD transgenic mice, and due to the AIE properties of TMNL, no additional rinsing process was necessary. It is believed that the probe reported in this work should be useful for the sensitive detection and accurate localization mapping of Aβ1–42 aggregates related to Alzheimer's disease. [ABSTRACT FROM AUTHOR]

We report a water-soluble AIEgen (TYDL) to be self-assembled into fluorescent organic nanoparticles (TYDLs) for specific sensing of SO2 in living hepatoma cells. It is demonstrated that the TYDLs were suitable for ratiometrically detecting endogenous and exogenous SO2 in mitochondria with good selectivity, low detection limit (75 nM) and excellent photostability (>30 min). These findings imply the great potential applications of TYDLs for the diagnosis of SO2-related diseases in cell biology. [ABSTRACT FROM AUTHOR]

Author(s): Yuki Kinjo [1]; Douglass Wu [2]; Gisen Kim [1]; Guo-Wen Xing [2]; Michael A. Poles [3, 4]; David D. Ho [4]; Moriya Tsuji [4, 5]; Kazuyoshi Kawahara [6, 7]; [...]

A dilactosyl‐dicyanovinyl‐functionalized tetraphenylethene (TPELC) was designed, synthesized and used for ratiometric sensing of cyanide. TPELC was comprised of three moieties (tetraphenylethylene, dicyanovinyl group and lactose unit) in one molecule, making TPELC water‐soluble and aggregation‐induced emission (AIE)‐active and selectively reactive to cyanide. Compared with other reported fluorescent probes containing dicyanovinyl group, TPELC is the first AIE luminogen to be assembled as fluorescent organic nanoparticles (FONs) for sensing of cyanide in water without the use of surfactant or the help of organic solvents based on the nucleophilic addition reaction. The detection mechanism was verified by liquid chromatograph mass spectrometry experiments and by protonation of cyanide to reduce the nucleophilicity of cyanide. In addition, TPELC was used for detection of the cyanide content of food samples and test strips were developed to simplify the detection procedure. [ABSTRACT FROM AUTHOR]

Liquid‐liquid phase separation has been recognized as an approach to realize cellular compartmentalization and create subdivisions of intracellular space into functional membraneless organelles. Multiphase coacervate droplets with complex, nested inner phases as a generic phenomenon are known to be involved in significant biochemical processes and facilitate specific functions. Herein, we present a strategy to develop molecular self‐sorting complexation that leads to the formation of lipid‐rich sub‐compartments in membraneless coacervate microdroplets. We also show the specific localization and visualization of hydrophobic lipid domains within multiphase hydrophilic droplets under a fluorescence microscope by developing a rationally synthesized aggregation‐induced emission (AIE)‐active molecule. The AIE probe with a tetraphenylethylene core and four water‐soluble glucosamine units exhibits high sensitivity and selectivity towards the lipid‐rich microdomains. We anticipate that the design of fluorescently localized self‐sorting liquid droplets will shed light on the research of mimicking multicompartalized organelles and help to understand dynamic reorganization of sub‐divided space in protocell systems. [ABSTRACT FROM AUTHOR]

Hypochlorous acid (HOCl) plays a crucial role in many physiological processes and is widely used as bleach, deodorant and fungicide. In this work, we designed an amphiphilic hydrazone fluorescent molecule THG‐1 containing hydrophilic sugar units and hydrophobic tetraphenylethylene unit for ratiometric detection of HOCl with high sensitivity and excellent selectivity based on HOCl‐triggered hydrolyzation reaction and aggregation‐induced emission (AIE) effect. The detection mechanism was verified by liquid chromatograph mass spectrometry experiments and scanning electron microscope (SEM) tests. Contrast experiments revealed that the numbers of lactose unit and hydrazone linker were essential for assembly of THG‐1 and detection of HOCl. In addition, THG‐1 was successfully used for imaging of exogenous and endogenous HOCl in living cells. [ABSTRACT FROM AUTHOR]

Sialic acids have recently gathered interests of many researchers. Sialidases and Siglecs are two important sialic acids‐related proteins that exist in biological systems, and aberrant sialoside‐Siglec or sialoside‐sialidase interactions are associated with many diseases, including autoimmunity, infection and cancer. Probing sialidase and Siglec effectively can enable the studies on the complex physiological functions of sialic acids. Over the last few decades, many sialic acid derivatives with modifications of parent skeleton and aglycon have been designed to increase the binding affinity with sialidase/Siglec or improve their detection efficiency. At the same time, in‐situ detection has also been aided by metabolic oligosaccharide engineering, in which incubating cells with sialic acid precursors could result in unnatural sialylated glycans incorporated into cellular membrane. In this minireview, we will predominantly highlight the development of sialidase and Siglec probing strategies using sialic acid analogues, clusters and precursors, which may further lay foundation for new diagnostics and treatments. [ABSTRACT FROM AUTHOR]

Two water‐soluble carbohydrate‐coated AIE‐activate fluorescent organic nanoparticles TPE3G and TPE4G were designed and synthesized for the detection of heparin. Different from the reported strategy, we not only utilized the general detection mechanism of electrostatic interactions, but also introduced the concept of carbohydrate‐carbohydrate interactions (CCIs) to enrich the detection mechanism of heparin. TPE3G can serve as an efficient "turn‐on" probe with higher selectivity towards heparin than TPE4G. TEM studies revealed that the micro‐aggregated TPE3G was encapsulated with the heparin chain to form a complex self‐assemblied composite and emits strong fluorescence. It is believed that the results illustrated in this study provide a novel strategy based on CCls to design water‐soluble and more efficient bio‐probes for various biological and clinical applications. [ABSTRACT FROM AUTHOR]