Search

As a highly toxic and widely used chemical, phosgene has become a serious threat to humankind and public security because of its potential use by terrorists and unexpected release during industrial accidents. For this reason, it is an urgent need to develop facile, fast, and selective detection methods of phosgene. In this Article, we have constructed a highly selective fluorescent sensor o-Pab for phosgene with a BODIPY unit as a fluorophore and o-phenylenediamine as a reactive site. The sensor o-Pab exhibits rapid response (15 s) in both colorimetric and turn-on fluorescence modes, high selectivity for phosgene over nerve agent mimics and various acyl chlorides and a low detection limit (2.7 nM) in solutions. In contrast to most undistinguishable sensors reported, o-Pab can react with phosgene but not with its substitutes, triphosgene and biphosgene. The excellent discrimination of o-Pab has been demonstrated to be due to the difference in highly reactive and bifunctional phosgene relative to its substitutes. Furthermore, a facile testing paper has been fabricated with poly(ethylene oxide) immobilizing o-Pab on a filter paper for real-time selective monitoring of phosgene in gaseous phase. [ABSTRACT FROM AUTHOR]

Two interesting dinuclear Zn(II)-compounds Zn 2 L 3 Cl 4 ( 1 ) and Zn 2 L 4 Cl 4 ( 2 ) were synthesized through the in situ zinc-induced reaction of simple pyridyl terminated (L 1 /L 2 )Schiff base ligands with ZnCl 2 in the mixture solvents of DMF and pyridine at 80 °C for three days (where L 1 = N-(2-pyridyl-methyl)-pyridine-2-carbaldimine, L 2 = 1-(pyridin-2-yl)-N-(pyridin-2-yl-methylene)ethanamine, L 3 = 2,3,5,6-tetra-(pyridin-2-yl)pyrazine, L 4 = 1,2-di(pyridin-2-yl)-bis(1-(pyridin-2-yl)-ethylidene)ethane-1,2-diamine). The elemental analysis (EA) and IR results reveal that in situ formation of one new ligand L 3 in 1 involves two C C coupling reactions from two molecular L 1 featuring H atom in α -carbon of C N moiety, while in situ formation of another new ligand L 4 in 2 involves one C C coupling reaction from L 2 featuring –CH 3 group in α -carbon of C N moiety. Obviously, different molecular structures between 1 and 2 closely related to the different substituents in simple Schiff base ligands. Moreover, the fluorescent properties of compounds 1 and 2 were also studied. [ABSTRACT FROM AUTHOR]

A new encoding strategy based on the host-guest structure was developed, where encoding is achieved by combinational use of a set of guest particles with different fluorescence intensity levels at various ratios. This system was proven to be well-defined and highly controllable. [ABSTRACT FROM AUTHOR]

The interaction of Ligupurpuroside A with bovine serum albumin (BSA) has been investigated by fluorescence spectra, UV-vis absorption spectra, three-dimensional (3D) fluorescence spectra, synchronous fluorescence spectra and circular dichroism (CD) spectra along with a molecular docking method. The fluorescence experiments indicate that Ligupurpuroside A can quench the intrinsic fluorescence of BSA through a combined quenching way at the low concentration of Ligupurpuroside A, and a static quenching procedure at the high concentration. The thermodynamic analysis suggests that hydrogen bonds and van der Waals forces are the main forces between BSA and Ligupurpuroside A. According to the theory of Förster׳s non-radiation energy transfer, the binding distance between BSA and Ligupurpuroside A was calculated to be 2.73 nm, which implies that energy transfer occurs between BSA and Ligupurpuroside A. All these experimental results have been validated by the protein-ligand docking studies which show that Ligupurpuroside A binds to the residues located in the hydrophobic cavity on subdomain IIA of BSA. In addition, conformation change of BSA was observed from three-dimensional fluorescence spectra, synchronous fluorescence spectra and circular dichroism spectra under experimental conditions. [ABSTRACT FROM AUTHOR]

A new fluorescent molecular probe 1 was designed and constructed by combining bovine serum albumin (BSA) and N , N′ -bis(salicylidene)ethylenediamine (salen). Stimulated by Zn 2 + , tris, or EDTAH 2 Na 2 , the distance between BSA and salen was regulated, which was accompanied by an obvious change in the fluorescence intensity at 350 or 445 nm based on Förster resonance energy transfer. Moreover, based on the encoding binary digits in these inputs and outputs applying positive logic conventions, a monomolecular circuit integrating one OR, three NOT, and three YES gates, was successfully achieved. [ABSTRACT FROM AUTHOR]

Several logic gates, which are commonly designed with DNA or organic molecules, rely on only one output mode. Here, a new molecular device was designed and constructed by combining bovine serum albumin and 5-sulfosalicylic acid. When MoO 4 2― , Tris(hydroxymethyl)aminomethane, EDTAH 2 Na 2 , Al 3+ , Trichloroacetic acid are used as inputs, changes in the fluorescent intensity at 350 nm and 406 nm were observed via FRET. Four molecular devices as a half-adder and three digital logic circuits were successfully constructed on the unimolecular platform by employing emission properties at different wavelengths as outputs. The advantage of the combined system was that many different functional molecular devices could be designed and assembled by employing protein and various organic molecules in aqueous solution. [ABSTRACT FROM AUTHOR]

Novel 3D barcodes with an extraordinarily high encoding capacity are developed through a flexible, accurate, and reproducible method. Here, the three dimensions refer to the size, fluorescence emission wavelength, and intensity of the barcodes. As a proof of concept, a 3D barcode library with an encoding capacity of 100 flow cytometry-distinguishable barcodes is achieved successfully by combining the multiscaled host particles with a set of guest nanoparticles owning to their individual different fluorescent intensity via an ingenious host-guest structure, where fluorescein isothiocyanate and a kind of quantum dots are separately loaded inside. Five-plexed tumor marker detection is further implemented, and the results demonstrate the strong feasibility of 3D barcodes in multiplex assays. [ABSTRACT FROM AUTHOR]