The synthesis and study of the fluorescent probe for sensing Cu2＋ based on a novel coumarin Schiff-base

A novel, fluorescent probe was synthesized from 2,4-dihydroxybenzaldehyde and 8-hydroxyquinoline for sensing Cu2+by the naked eye. The structure was confirmed by IR, MS,1H NMR,13 C NMR and the spectral properties of the probe were investigated. It exhibited strong fluorescence responses toward Cu2+and high selectivity over other metal ions. The binding constant between the probe and Cu2+was calculated using Benesi–Hildebrand equation.     

Novel N-heteroaromatic dyes for textile substrates

This study reports the synthesis and characterization of quinoline derivatives. The synthesized quinoline compounds were applied to the dyeing treatment of acrylic fabrics. The color fastness to washing and light of quinoline compound-dyed fabrics was examined. Human skin HaCaT cell line was also used for the skin cytotoxicity evaluation of the quinoline compound-dyed acrylic fabrics.     

New cytotoxic annonaceous acetogenin mimetics having a nitrogen-heterocyclic terminal and their application to cell imaging

A terminal unsaturated lactone or its equivalent is commonly believed to be essential for the cytotoxicity of natural annonaceous acetogenins and their artificial mimetics. In this work, we discovered a series of new cytotoxic ethylene glycol ether-containing mimetics, in which a variety of simple aliphatic nitrogen-heterocycles were introduced to replace the lactone terminal of AA005 (1), a representative bioactive polyether mimic identified from our previous research, for the first time. Among these, mimic 4 bearing a terminal piperazine was found to be the most potent compound against the proliferation of three cancer cells. Based on our new findings, a fluorescent probe 7 was also developed and successfully applied to the imaging of cancer cells. This work provides a new strategy for developing simpler cytotoxic mimetics of natural annonaceous acetogenins and molecular tools for biological imaging.     

2-(1,2,3-Triazol-4-yl)pyridine-containing ethynylarenes as selective ‘turn-on’ fluorescent chemosensors for Ni(II)

A series of ethynylarene compounds containing 2-(1,2,3-triazol-4-yl)pyridine chelating units were studied as fluorescent chemosensors for metal cations in aqueous solution. Analogs possessing two chelating units bridged by either 1,4-diethynylphenyl or 2,7-diethynylnaphthyl subunits displayed large hypsochromic shifts coupled with signal intensification when exposed to increasing concentrations of Ni(II), a unique response among 22 metal cation analytes. This response was shown to be reversible, and is proposed to derive from disruption of aggregate formation upon Ni(II) binding at the peripheral chelating units.     

A new colorimetric and fluorescent bifunctional probe for Cu and F ions based on perylene bisimide derivatives

A perylene bisimide derivative (PBI) based colorimetric and fluorescent bifunctional probe PAM-PBI was designed and synthesized. It was highly selective and sensitive for distinguishing both Cu²⁺ and F⁻ from other ions through a conspicuous change of UV–vis and fluorescence spectra. The recognition of Cu²⁺ by PAM-PBI showed an obvious color change from rose red to purple in aqueous solution, while the sensing of F⁻ gave a marked color change from rose red to light green in THF.     

New methodology for the synthesis of 25-hydroxyvitamin D conjugates

A new method for synthesizing regiospecific 3-position vitamin D conjugates is described. Reaction of either 25-dihydroxyvitamin D2 or 25-dihydroxyvitamin D3 with p-nitrophenylchloroformate resulted in conversion to the respective 3-p-nitrophenylcarbonates. Reaction of the p-nitrophenylcarbonates with amines produced the 3-carbamates in good yield. Careful selection of commercially available amines and non-acidic conditions made this pathway amenable to the preparation of fluorescent, chemiluminescent, or biotinylated conjugates. This strategy offers a general method for the preparation of vitamin D conjugates.     

Fluorescent Determination of Mercury(II) Using Rhodamine B Immobilized on Polystyrene Microspheres

A novel microsphere-based fluorescent sensor 1 for determination of Hg(II) in food samples has been successfully synthesized and its fluorescent sensing properties were investigated in detail. Polystyrene microsphere was innovatively surface modified by a rhodamine derivative; therefore sensor 1 was a fluorescent sensor with high polymer material properties of polystyrene and the optical properties of a fluorescent probe. Sensor 1 displayed high selectivity, good anti-interference performance, and instantaneous response to Hg(II). The fluorescence intensity of sensor 1 showed a linear response to Hg(II) in the concentration range of 0?µM to 8?µM with a detection limit of 0.439?µM. The most valuable advantage was that sensor 1 was recyclable and environmentally-friendly. This proposed sensor 1 was applied to monitor the content of Hg(II) in real food samples, such as tap water, rice, and anglerfish. The recovery range of tap water was from 92.60 to 105.80%, the recovery range of rice was from 90.45 to 106.10%, and the recovery range of anglerfish was from 91.30 to 105.84%. The relative error was below 10% in spiked recovery studies, suggesting that fluorescent sensor 1 provides a simple, efficient, and promising method for determination of Hg(II) in complex matrices.     

Twisted Push‐Pull Probes with Turn‐On Sulfide Donors

Planarizable and polarizable dithieno[3,2‐b ;2′,3′‐d ]thiophene (DTT ) dimers have been introduced recently as fluorescent probes that report on membrane fluidity with red shifts in excitation, i.e . planarization in the ground state. In this study, we elaborate on the hypothesis that twisted push‐pull probes could perform best in the presence of one unorthodox substituent that acts as a weak acceptor with electron‐rich and as a strong donor with electron‐poor aromatics. According to Hammett constants, we thought that sulfides could provide access to such a conceptually innovative donor‐acceptor switch. To elaborate on this hypothesis, we here describe the design, synthesis and evaluation of a comprehensive series of twisted push‐pull probes with turn‐on sulfide donors. Their planarization is explored in lipid bilayer membranes of different thickness and fluidity from liquid‐disordered to liquid‐ordered and solid‐ordered phases. Results from membranes are compared to the planarization of turn‐on mechanophores in crystals, proteins, and cyclodextrin macrocycles of varied diameter.