新型罗丹明型荧光探针的合成及其对Cu(Ⅱ)的识别性能

罗丹明B-酰肼和8-羟基-7-喹啉醛经缩合反应合成了一个新型的荧光探针(L),其结构经1H NMR,MS和元素分析表征。考察了L对金属离子的识别性能,结果表明:在乙腈溶液[V(MeCN)∶V(H2O)=19∶1,pH7.0]中,L可高选择性的识别Cu(Ⅱ)。Cu(Ⅱ)能诱导L内酰胺结构开环并形成1∶2型的配合物L-Cu(Ⅱ),这一过程是可逆的。     

Direct Blue 71 staining as a destaining‐free alternative loading control method for Western blotting

In Western blotting, a suitable loading control is indispensable for correcting errors in the total amount of loaded protein. Immunodetection of housekeeping proteins and total protein staining have traditionally been used as loading control methods. Direct Blue 71 (DB71) staining—a novel, sensitive, dye‐binding staining method compatible with immunodetection—may offer advantages over these traditional loading control methods. Three common neuroscientific samples (human plasma, human oligodendrocytes, and rat brain) were employed to assess DB71 staining as a loading control method for Western blotting. DB71, CBB, one traditional housekeeping protein, and one protein of interest were comparatively assessed for reliability and repeatability and linear dynamic range over 2.5–40 μg of protein loaded. DB71's effect on the reliability and repeatability and linear dynamic range of immunoreaction were also assessed. Across all three sample types, DB71 was either equivalent or superior to CBB and housekeeping protein‐based methods in terms of reliability and repeatability and linear dynamic range. Across all three sample types, DB71 staining did not impair the reliability and repeatability or linear dynamic range of immunoreaction. Our results demonstrate that the DB71 staining can be used as a destaining‐free alternative loading control method for Western blotting.     

A New Coordination Polymer Containing 4-[（8-Hydroxy-5-quinolinyl）azo]-benzenesulfonic Acid： Synthesis,Structure and Fluorescent Property

A new coordination polymer, {[CdL（en）]＇DMF}n （1, H2L = 4-[（8-hydroxy-5- quinolinyl）azo]-benzenesulfonic acid, en = ethylenediamine, DMF = N,N-dimethylformamide）, has been solvothermally synthesized and structurally characterized by single-crystal X-ray diffrac- tion, infrared （IR） spectra, elemental analysis, powder X-ray diffractions （PXRD） and thermo- gravimetric analysis （TGA）. Compound 1 crystallizes in monoclinic, space group P2Jc with a = 14.6525（9）, b = 13.3917（9）, c = 11.8838（8） A, β = 101.2290（10）°, V = 2287.2（3） A3, Z = 4, C20H24CdN6OsS, Mr = 572.91, Dc. = 1.664 mg-mm-3, F（000） = 1160, p = 1.091 mm-1, R = 0.0232 and wR = 0.0587 for 3597 observed reflections （I 〉 2σ（I））. Compound 1 exhibits a one-dimensional （1D） double-chain structure which is further connected through hydrogen bonding and π-π interactions into a three-dimensional （3D） supramolecular network. In addition, it exhibits blue fluorescence at room temperature in the solid state.     

A ratiometric fluorescent probe for zinc ions based on the quinoline fluorophore

A ratiometric fluorescent zinc probe 1 of carboxamidoquinoline with a carboxylic acid group was designed and synthesised. Probe 1 exhibits high selectivity for sensing Zn²⁺; about a 13-fold increase in fluorescence emission intensity and an 82?nm red-shift of fluorescence emission are observed upon binding Zn²⁺ in EtOH/H₂O (1?:?1, V/V) solution. The ratiometric fluorescence response is attributed to the 1?:?1 complex formation between probe 1 and Zn²⁺ which has been utilised as the basis for the selective detection of Zn²⁺. The analytical performance characteristics of the proposed Zn²⁺-sensitive probe were investigated. The linear response range covers a concentration range of Zn²⁺ from 2.0?×?10^?6 to 5.0?×?10^?5?mol?L^?1 and the detection limit is 2.7?×?10^?7?mol?L^?1. The determination of Zn²⁺ in both tap and river water samples shows satisfactory results.     

A Triazatruxene‐Based Glycocluster as a Fluorescent Sensor for Concanavalin A

A new triazatruxene‐based fluorescent glycocluster has been designed, synthesized, and fully characterized by NMR spectroscopy and mass spectrometry. Furthermore, its specific and selective binding properties with concanavalin A (Con A) have been investigated by fluorescence spectroscopy, circular dichroism (CD) spectroscopy, and turbidity assay. The obtained results showed that the multivalent mannose‐modified triazatruxene exhibited specific binding with Con A, but no binding to peanut agglutinin (PNA) lectin or bovine serum albumin (BSA), corresponding to a two‐orders‐of‐magnitude higher affinity than that of monovalent mannose ligands. Most interestingly, a fluorescence enhancement of the triazatruxene‐based glycocluster was observed upon binding with Con A because of hydrophobic interactions involving sites close to the triazatruxene moiety. Furthermore, the inhibitory ability of the triazatruxene‐based glycocluster against ORN178‐ induced haemagglutination has been investigated by haemagglutination inhibition assay. The results indicated selective binding with ORN178.     

Integration of the 1,2,3‐Triazole “Click” Motif as a Potent Signalling Element in Metal Ion Responsive Fluorescent Probes

In a systematic approach we synthesized a new series of fluorescent probes incorporating donor–acceptor (D‐A) substituted 1,2,3‐triazoles as conjugative π‐linkers between the alkali metal ion receptor N‐phenylaza‐[18]crown‐6 and different fluorophoric groups with different electron‐acceptor properties (4‐naphthalimide, meso‐phenyl‐BODIPY and 9‐anthracene) and investigated their performance in organic and aqueous environments (physiological conditions). In the charge‐transfer (CT) type probes 1 , 2 and 7 , the fluorescence is almost completely quenched by intramolecular CT (ICT) processes involving charge‐separated states. In the presence of Na⁺ and K⁺ ICT is interrupted, which resulted in a lighting‐up of the fluorescence in acetonitrile. Among the investigated fluoroionophores, compound 7 , which contains a 9‐anthracenyl moiety as the electron‐accepting fluorophore, is the only probe which retains light‐up features in water and works as a highly K⁺/Na⁺‐selective probe under simulated physiological conditions. Virtually decoupled BODIPY‐based 6 and photoinduced electron transfer (PET) type probes 3 – 5 , where the 10‐substituted anthracen‐9‐yl fluorophores are connected to the 1,2,3‐triazole through a methylene spacer, show strong ion‐induced fluorescence enhancement in acetonitrile, but not under physiological conditions. Electrochemical studies and theoretical calculations were used to assess and support the underlying mechanisms for the new ICT and PET 1,2,3‐triazole fluoroionophores.     

Fluorescent Protein Capped Mesoporous Nanoparticles for Intracellular Drug Delivery and Imaging

A multifunctional system for intracellular drug delivery and simultaneous fluorescent imaging was constructed by using histidine‐tagged, cyan fluorescent protein (CFP)‐capped magnetic mesoporous silica nanoparticles (MMSNs). This protein‐capped multifunctional nanostructure is highly biocompatible and does not affect cell viability or proliferation. The CFP acts not only as a capping agent, but also as a fluorescent imaging agent. The nanoassembly was activated by histidine‐based replacement, leading to release of drug molecules encapsulated in the nanopores into the bulk solution. The fluorescent imaging functionality would allow noninvasive tracking of the nanoparticles in the body. By combining the drug delivery with cell‐imaging capability, these nanoparticles may provide valuable multifunctional nanoplatforms for biomedical applications.     

Multifunctional Core‐Shell‐Corona‐Type Polymeric Micelles for Anticancer Drug‐Delivery and Imaging

We have developed core‐shell‐corona‐type polymeric micelles that can integrate multiple functions in one system, including the capability of accommodating hydrophobic dyes into core and hydrophilic drug into the shell, as well as pH‐triggered drug‐release. The neutral and hydrophilic corona sterically stabilizes the multifunctional polymeric micelles in aqueous solution. The mineralization of calcium phosphate (CaP) on the PAA domain not only enhances the diagnostic efficacy of organic dyes, but also works as a diffusion barrier for the controlled release.     

A Versatile Long‐Wavelength‐Absorbing Scaffold for Eu‐Based Responsive Probes

Coumarin‐sensitized, long‐wavelength‐absorbing luminescent Eu^III‐complexes have been synthesized and characterized. The lanthanide binding site consists of a cyclen‐based chelating framework that is attached through a short linker to a 7‐hydroxycoumarin, a 7‐B(OH)₂‐coumarin, a 7‐O‐(4‐pinacolatoboronbenzyl)‐coumarin or a 7‐O‐(4‐methoxybenzyl)‐coumarin. The syntheses are straightforward, use readily available building blocks, and proceed through a small number of high‐yielding steps. The sensitivity of coumarin photophysics to the 7‐substituent enables modulation of the antenna‐absorption properties, and thus the lanthanide excitation spectrum. Reactions of the boronate‐based functionalities (cages) with H₂O₂ yielded the corresponding 7‐hydroxycoumarin species. The same species was produced with peroxynitrite in a ×10⁶–10⁷‐fold faster reaction. Both reactions resulted in the emergence of a strong ≈407 nm excitation band, with concomitant decrease of the 366 nm band of the caged probe. In aqueous solution the methoxybenzyl caged Eu‐complex was quenched by ONOO^?. We have shown that preliminary screening of simple coumarin‐based antennae through UV/Vis absorption spectroscopy is possible as the changes in absorption profile translate with good fidelity to changes in Eu^III‐excitation profile in the fully elaborated complex. Taken together, our results show that the 7‐hydroxycoumarin antenna is a viable scaffold for the construction of turn‐on and ratiometric luminescent probes.