Photophysics and Photochemistry of Molecular Recognition and Sensing with Metal-Directed Macrocyclic Systems

<a></a><a></a><a></a><a></a><a></a><a></a><a></a><a>The development of highly-sensitive recognition of </a><a></a><a></a><a></a><a></a><a>hazardous </a>chemicals, such as volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs), is of significant importance because of their widespread social concerns related to environment and human health. Here, we report a three-dimensional (3D) covalent organic framework (COF, termed JUC-555) bearing tetraphenylethylene (TPE) side chains as an aggregation-induced emission (AIE) fluorescence probe for sensitive molecular recognition.<a></a><a> </a>Due to the rotational restriction of TPE rotors in highly interpenetrated framework after inclusion of dimethylformamide (DMF), JUC-555 shows impressive AIE-based strong fluorescence. Meanwhile, owing to the large pore size (11.4 Å) and suitable intermolecular distance of aligned TPE (7.2 Å) in JUC-555, the obtained material demonstrates an excellent performance in the molecular recognition of hazardous chemicals, e.g., nitroaromatic explosives, PAHs, and even thiophene compounds, via a fluorescent quenching mechanism. The quenching constant (KSV) is two orders of magnitude better than those of other fluorescence-based porous materials reported to date. This research thus opens 3D functionalized COFs as a promising identification tool for environmentally hazardous substances.

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Biomimetic Extracellular Vesicles Embedded with Black Phosphorus for Molecular Recognition-Guided Biomineralization

10.26434/chemrxiv.6721553.v1 ◽

2018 ◽

Author(s):

Yingqian Wang ◽

Xiaoxia Hu ◽

Lingling Zhang ◽

Chunli Zhu ◽

Jie Wang ◽

...

Keyword(s):

Molecular Recognition ◽

Extracellular Vesicles ◽

Inorganic Phosphate ◽

Physiological Activity ◽

Medical Engineering ◽

Matrix Vesicles ◽

Black Phosphorus ◽

Photothermal Effect ◽

Biological Processes ◽

Extracellular Environment

Extracellular vesicles (EVs) are involved in the regulation of cell physiological activity and the reconstruction of extracellular environment. Matrix vesicles (MVs) are a type of EVs, and they participate in the regulation of cell mineralization. Herein, bioinspired MVs embedded with black phosphorus are functionalized with cell-specific aptamer (denoted as Apt-bioinspired MVs) for stimulating biomineralization. The aptamer can direct bioinspired MVs to targeted cells, and the increasing concentration of inorganic phosphate originated from the black phosphorus can facilitate cell biomineralization. The photothermal effect of the Apt-bioinspired MVs also positively affects mineralization. In addition, the Apt-bioinspired MVs display outstanding bone regeneration performance. Considering the excellent behavior of the Apt-bioinspired MVs for promoting biomineralization, our strategy provides a way of designing bionic tools for studying the mechanisms of biological processes and advancing the development of medical engineering.

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Arylboronic Acids in Self-condensation of Glucosamines Forming Deoxyfructosazine, Catalysts or Reagents?

10.26434/chemrxiv.7528376 ◽

2019 ◽

Author(s):

Meifeng Wang ◽

Gan Zhu ◽

Yiqun Li ◽

Liuqun Gu

Keyword(s):

Molecular Recognition ◽

Boric Acid ◽

Boronic Acid ◽

Catalytic Mechanism ◽

Organic Transformations ◽

Food Industries ◽

Arylboronic Acids ◽

Excess Amount ◽

Phenyl Boronic Acid ◽

Boron Acid

Arylboronic acids were widely used as efficient catalysts in direct amide formation and other organic transformations. Surprisingly, reports on their use as catalysts in carbohydrates synthesis are very rare even though boron acid-diol complexation was extensively investigated in molecular recognition for saccharides and so on. Here we developed an efficient arylboronic acids catalyzed dimerization of glucosamines forming deoxyfructosazine which is important compound in pharmaceutical and food industries, against a commonly held belief that excess amount of phenyl boronic acid (or boric acid) is a must. A catalytic mechanism was also proposed and arylboronic acids instead of their boronates was identified as catalysts.

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