查看更多>>摘要：The paper presents a comparative analysis of the effect of structural and solvation factors on the spectral characteristics and lipophilicity of a series of iodo-and bromosubstituted zinc(II),cadmium(II),and boron(III)dipyrromethethenes.The studied chelates [ZnL2],[CdL2],and [BF2L] fluoresce in organic solvents solutions with a quantum yield from 1% to 50%,depending on their molecular structure and the solvent nature.It was noted that the high sensitivity of [ZnL2] and [CdL2] fluorescence to the presence of electron-and proton-donor solvents are due to the additional coordination of M-Solv or acid-base interactions ≥ N···H-Solv.It was found that [BF2L] have up to 1.5 times higher lipophilicity compared to [ZnL2] with the same functional substitution.The hydrophobicity of 4,4'-dibromosubstituted luminophores is noticeably higher than that of 5,5'-dibromosub-stituted analogs.The obtained results indicate the prospects for the development of new effective fluorescent markers and sensors of medium polarity based on halogen-substituted dipyrromethenates.
查看更多>>摘要：Multifunctional electrochromic materials are widely used in optoelectronic devices.Pyrene is a π-electron-rich group with fluorescence properties.Ester-functionalized pyrene derivatives potentially have interesting multifunctional properties such as electrochromic and electrofluorochromic characteristics.In this work,mono-,di-,tri-,and tetra-ester-substituted pyrene derivatives were synthesized,and the effects of the number of ester substituents on their photophysical,electrochemical,electrochromic,and electrofluorochromic properties were investigated.The number of ester substituents significantly affected these properties.An increase in the number of ester substituents on the pyrene caused red shifts in the absorption and emission spectra,a decrease in the driving voltage,and changes in the electrochromic colored states and electrofluorochromic performance.Mono-,di-,and tri-ester-functionalized pyrene derivatives showed good electrochromic properties,namely good switching stabilities,high optical contrasts,rapid responses,and high coloration efficiencies.Mono-and tri-ester-functionalized pyrenes gave good electrofluorochromic performances with reversible fluorescence quenching-fluorescence restoring between colored and bleached states during the electrochromic process.Ester-functionalized pyrene derivatives were successfully used in two functional digital displays with vivid colors.These results show that ester-functionalized pyrene derivatives with good electrochromic and electrofluorochromic properties are promising candidates for use in various applications,e.g.,digital displays,organic electroluminescence displays,electronic shelf labels,energy-saving windows,and electronic paper.
查看更多>>摘要：Imaging technology based on fluorescent dyes is of great significance in tumor diagnosis.The fluorescent probes with antitumor effect at the same time can further expand the application of the probes in tumor.Inspired by the rigid cyclic structure of heme,the isomers cis/trans-BP with intramolecular eight-membered ring structure were obtained by innovatively combining two groups in unrelated fields,BODIPY and pyrimidine,together through substitution reaction and then by simple column chromatography.cis/trans-BP has stable spectral properties and can generate obvious fluorescence signals in organisms.The transmission electron microscope visually showed the uptake and distribution of the compounds by HeLa,and the subsequent apoptosis.The antitumor mechanisms of the compounds were further studied by flow cytometry.The results showed that trans-BP retained the function of fluorescent probe and simultaneously possessed antitumor activity.
查看更多>>摘要：α-Cyanostilbene derivatives are known as fluorescent photochromic molecules that could be used to realize emission colour change or on/off switching via photo-induced isomerization or cycloaddition.Comparing with isomerization,photocycloaddition is less studied due to its critical molecular position and alignment requirement for molecular packing.In this work,biphenyl-based cyanostilbenic compounds 1-3 were synthesized,which exhibit characteristic mechanofluorochromic(MFC)response behaviour.Under force stimuli,the luminescent colour has bathochromic shift from blue to green,together with the phase transition from crystal to amorphous state.Photochromic fluorescent response attributed to photo-induced [2 + 2] cycloaddition could take place instantly in amorphous state,rather than crystals.The MFC response can be successfully used to monitor the photoreaction process,giving rise to quantitative dimerized product.The single crystal structure of compound 2 revealed its photostable feature.The formation of excimers in ground amorphous state,together with the me-chanical shearing,facilitates the occurrence of cycloaddition.Subsequently,the recovery process could be achieved thermally or under UV irradiation.
查看更多>>摘要：Golgi apparatus is an important organelle responsible for transporting proteins in cells.Accurate monitoring of Golgi apparatus status by targeting fluorescence imaging technology is of great significance for visualization of Golgi apparatus'physiological status.Cyclooxygenase-2(COX-2)is a protease on the Golgi apparatus surface of cells.By means of hydrogen bonding between COX-2 and sulfonamide groups,orange-emitting Golgi apparatus-targeting carbon dots(GTCDs)were developed for the efficient imaging monitoring of Golgi apparatus.GTCDs were synthesized from p-phenylenediamine and benzene sulfonamide by one-step solvothermal methods.GTCDs had uniform size(~3.36 nm),graphitized structure,maximum emission wavelength of 612 nm,low cytotoxicity,24 h metabolic time,and good photostability.In addition,GTCDs had an excellent Golgi apparatus-targeting effect(average Pearson's co-localization coefficient = 0.92)and ultrafast imaging capability of Golgi apparatus(imaging immediately after the addition of GTCDs).The selective targeting of GTCDs to Golgi apparatus was attributed to the binding of the sulfonamide moiety on the surface of GTCDs to the active pocket site of COX-2 in Golgi apparatus through hydrogen bonds,which led to the localization of GTCDs to Golgi apparatus.It is believed that GTCDs have great potential in the fields of precise organelle imaging and targeting drug delivery as Golgi apparatus-targeting biological fluorescent probes.
查看更多>>摘要：Melanin is a complex group of natural pigment substance,and it shows excellent biological and biomedical applications which is commonly present in algae,fungi,bacteria,cephalopoda,and sea cucumber.From the past few decades,great attention has been given to melanin and its derivative for the product development in the area of medical,industrial,food and cosmetic industries.In addition,melanin plays an important in pharmaceutical product development in antioxidant,anti-inflammatory,immunomodulatory,radioprotective,and gastrointestinal benefits.In this review,we focus on melanin production from various marine species,summarized Purification and extraction strategies of various marine melanin with their analyzes and also their application in medical and industries.
查看更多>>摘要：In this work,we successfully report the design and synthesis of rod-like CoAl2O4/halloysite hybrid pigment from zeolitic imidazolate framework-67(ZIF-67,a Co-based MOF)and tubular halloysite via a facile two-step route for the first time.The as-prepared nanostructures were thoroughly characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),Fourier transform infrared reflection(FTIR Spectroscopy),thermogravimetric and differential scanning calorimetry(TG-DSC),X-ray photoelectron spectrometer(XPS),ultraviolet-visible spectrometry(UV-vis)and CIE L* a* b* colorimetric method.XRD patterns indicated that the presence of CoAl2O4 spinel was observed at various temperatures ranging from 800 to 1100 ℃.The SEM and TEM images showed that the nano-pigment has a rod-like hybrid structure composed of nano CoAl2O4 particles and SiO2.The color performance of the fabricated pigments was evaluated and given suitable color coordinates(L* = 44.72,a* =-14.40,b* =-37.83)and(L* = 42.57,a* =-7.68,b* =-41.14)at the calcination temperature of 1100 ℃ for 2 h and 3 h,respectively.The mechanism study indicated that these composites were formed by C03O4 derived of ZIF-67 as highly active cobalt source and Al2O3 decomposed from halloysite substrate as aluminum source.In addition,the corrosion resistance test showed that the CoAl2O4 composites retain crystalline stability,almost no color deviation in CIE chromatic system even after 1 M HC1 leaching.Furthermore,the CoAl2O4/halloysite exhibited excellent thermal and suspension stability,which indicated it could be a promising candidate for ceramic glazes and water-borne coatings.These findings provide insight into a new strategy for the synthesis of clay mineral-based ceramic pigment.
查看更多>>摘要：To address poor photodynamic efficacy against hypoxic tumor cells,we have developed a smart photosensitizing agent Ion-BDP whose phototherapeutic mode can be regulated by nitroreductase(NTR)that is rich in hypoxic tumor cells.This photosensitizer(PS)can eliminate outer aerobic tumor cells mainly by generating reactive oxygen species(ROS)upon illumination.Moreover,Ion-BDP is highly sensitive to NTR and capable of con-verting to BDP by removing the 4-nitrobenzyl group via reduction and subsequent self-immolation under hyp-oxic condition.The formed BDP behaving as a highly efficient photothermal agent can further kill the hypoxic tumor cells by photothermal therapy(PTT).The synergistic antitumor effects of this PS have been verified by in vitro and in vivo experiments.This study may provide a potential tactic to precisely overcome the inherent therapeutic difficulty arising from 02-distributional heterogeneity in solid tumors.In brief,we have designed,synthesized and evaluated a novel NTR-regulated PS and found that it can remarkably inhibit tumor growth in both hypoxic and normoxic conditions,which is proven to be a distinctive strategy for maximizing photo-therapeutic efficacy.
查看更多>>摘要：In modern organic synthesis,green organic synthesis technology has become an important research direction in the field of chemistry and chemical engineering.Coumarin dyes play an important role in industrial chemistry,biochemistry and material science,so the synthesis of fluorescent dyes has been an important problem in modern organic synthesis.Therefore,the design and discovery of green organic synthesis of coumarin derivatives is very important.Hypochlorous acid/hypochlorite as a ROS plays an important role in diagnosis and treatment of diseases.To date,many probes have been developed for HClO/ClO~-detection.Among them,some probes have poor selectivity and slow response time for HC10/ClO~-,which greatly limits the practical application value of probes.In this work,the reaction of 7-(diethylamino)-2H-chromene-2-thione with hypochlorite produces 7-(diethylamino)-2H-chromen-2-one,which is a novel green synthesis method of coumarin dye.The experimental results showed that the reaction is a ratiometric,selective and sensitive fluorescence system for the recognition of hypochlorite.This method has been successfully to detection of hypochlorite in HeLa/HNEpC cells,zebrafish and actual sample detection.
查看更多>>摘要：A series of thirteen 2-acyl-6,7-dihydro-1H,5H-pyrazolo[1,2-a]pyrazole derivatives were synthesized by using aj copper-catalyzed azomethine-imine-alkyne cycloaddition as a key step.These bimane-related fluorescent com-pounds with λ_(ex)= 338-400 nm and λ_(em)= 522-644 nm exhibit interesting and promising optical properties,including a remarkably large Stokes shift(150-268 nm),positive solvatochromism,and strong dependence of emission intensity on pH in a range of pH 2-10.The benzotriazolide-and N-succinimidyl ester-functionalized compounds were successfully used as fluorescent probes for protein labelling.
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