Upconversion luminescence nanoparticles(UCNPs)have shown promising applications in biomedical fields as luminescent probes because of their excellent advantages such as single excitation with multicolor emission,low a...Upconversion luminescence nanoparticles(UCNPs)have shown promising applications in biomedical fields as luminescent probes because of their excellent advantages such as single excitation with multicolor emission,low autofluorescence,and deep penetration.But the biological applications of such nanomaterials are still restricted due to the unfavorable surface properties.In this work,we develop a facile one-pot hydrothermal route to obtain O-carboxymethyl chitosan(OCMC)-wrapped NaYF4:Yb3+/Tm3+/Er3+red UCNPs which have been used for targeted cell luminescence imaging directly and efficiently.The successful coating of the UCNPs by OCMC has been confirmed by Fourier-transform infrared(FTIR)spectroscopy and dynamic light scattering(DLS)studies.Transmission electron microscopy(TEM),powder X-ray diffraction(XRD),thermogravimetric analysis(TGA),and photoluminescence(PL)spectra have been used to characterize the size,composition and emission color of the samples,respectively.Due to the good biocompatibility,water-solubility,and strong UC luminescence,these hydrophilic nanocrystals will open up new avenues in further bioapplications.展开更多
A new schiff base of phenothiazine derivative was designed for ratiometric sensing of Cd2＋ selectively. Upon the addition of Cd2＋ to the solution of phenothiazine derivative, the fluorescence intensity of it was enh...A new schiff base of phenothiazine derivative was designed for ratiometric sensing of Cd2＋ selectively. Upon the addition of Cd2＋ to the solution of phenothiazine derivative, the fluorescence intensity of it was enhanced in a linear fashion and the maximum fluorescence peak exhibited a blue shift from 575 nm to 525 nm. This ratiometric fluorescent sensor displays a very high sensitivity（detection limits were 0.34 and 1.0μmol/L of Cd2＋ using the visual fluorescence changes and UV-Vis changes, respectively）, a rapid response time（〈10 s） and high selectivity for Cd2＋ over other transition metal ions. Moreover, the living cells image experiments also demonstrate the value of the sen- sor in fluorescent visualization of Cd2＋ in the environmental and biological systems.展开更多
α-Cyanostilbene(CS)based organic luminescent materials with eficient electrical conductivity,aggregation-induced enhanced emission,and controllable multi-colour emission properties,have been aroused wide attention by...α-Cyanostilbene(CS)based organic luminescent materials with eficient electrical conductivity,aggregation-induced enhanced emission,and controllable multi-colour emission properties,have been aroused wide attention by scientists over the past few years.Self-assembly of cS-motif in aqueous me-dia refers to an environment-friendly method for preparing luminescent materials.However,it is still challenging to control the intrinsic hydrophobic properties of the organic components in aqueous media.In this study,an amphiphilic dicyanostilbene-functionalized thiophene(ACSTP)derivative was synthe-sized.Z-AcSTP was identified to dissolve in different organic solvents,accompanied with strong and tun-able fluorescence emission.However,when Z-AcSTP was dispersed in water,it was self-assembled into nanofibers,and the fluorescence was red shifted,accompanied with sharp decrease of intensity com-pared with that in DMSO.Furthermore,Z-form of ACSTP to its E-form under 365 nm irradiation led to the morphology transformation from nanofibers to nanosheets.Notably,upon addition of water-soluble pillar[5]arene(wP5),the nanofibers were transformed into fluorescent hollow particles due to the host-guest interactions between the pyridinium group and WP5 and the obtained fluorescent particles can be further applied in living cell imaging.展开更多
Synthesis and functionalization of novel macrocyclic host molecules are important topics in supramolecular chemistry.In this work,the first amphiphilic[2]biphenyl-extended pillar[6]arene(AM-[2]BP-ExP6)was designed and...Synthesis and functionalization of novel macrocyclic host molecules are important topics in supramolecular chemistry.In this work,the first amphiphilic[2]biphenyl-extended pillar[6]arene(AM-[2]BP-ExP6)was designed and synthesized with poly(ethylene glycol)chains as the hydrophilic tails and a rigid cavity as the hydrophobic core.Due to its amphiphilic nature,AM-[2]BP-ExP6 could self-assemble to stable fibers in water.What’s more,AM-[2]BP-ExP6 could associate with quaternary ammonium modified tetraphenylethylene guest(QTPE)to form a 2:1 host-guest complex,accompanied by significant enhanced fluorescence.Interestingly,different like AM-[2]BP-ExP6,AM-[2]BP-ExP6⊃QTPE host-guest complex selfassembled into fluorescent particles with diameter about 310 nm,the obtained fluorescent particles can be further employed in living cell imaging.展开更多
Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth, are major repositories for photosynthetically accumulated carbon, and, in addition, impact greatly on the human use of plants...Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth, are major repositories for photosynthetically accumulated carbon, and, in addition, impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose, hemicelluloses, and pectic polysaccharides. During the evolution of land plants, polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.展开更多
Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has b...Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence： materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris（8-hydroxyquinolinate） displayed a bright green emission suitable for organic light emitting diodes （OLEDs） was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibility of using NIR emission of ions such 展开更多
基金supported in part by the National Natural Science Foundation of China(21275015,21075009)the National Basic Research Program of China(2011CB932403)the Program for New Century Excellent Talents in University of China(NCET-10-0213)
文摘Upconversion luminescence nanoparticles(UCNPs)have shown promising applications in biomedical fields as luminescent probes because of their excellent advantages such as single excitation with multicolor emission,low autofluorescence,and deep penetration.But the biological applications of such nanomaterials are still restricted due to the unfavorable surface properties.In this work,we develop a facile one-pot hydrothermal route to obtain O-carboxymethyl chitosan(OCMC)-wrapped NaYF4:Yb3+/Tm3+/Er3+red UCNPs which have been used for targeted cell luminescence imaging directly and efficiently.The successful coating of the UCNPs by OCMC has been confirmed by Fourier-transform infrared(FTIR)spectroscopy and dynamic light scattering(DLS)studies.Transmission electron microscopy(TEM),powder X-ray diffraction(XRD),thermogravimetric analysis(TGA),and photoluminescence(PL)spectra have been used to characterize the size,composition and emission color of the samples,respectively.Due to the good biocompatibility,water-solubility,and strong UC luminescence,these hydrophilic nanocrystals will open up new avenues in further bioapplications.
文摘A new schiff base of phenothiazine derivative was designed for ratiometric sensing of Cd2＋ selectively. Upon the addition of Cd2＋ to the solution of phenothiazine derivative, the fluorescence intensity of it was enhanced in a linear fashion and the maximum fluorescence peak exhibited a blue shift from 575 nm to 525 nm. This ratiometric fluorescent sensor displays a very high sensitivity（detection limits were 0.34 and 1.0μmol/L of Cd2＋ using the visual fluorescence changes and UV-Vis changes, respectively）, a rapid response time（〈10 s） and high selectivity for Cd2＋ over other transition metal ions. Moreover, the living cells image experiments also demonstrate the value of the sen- sor in fluorescent visualization of Cd2＋ in the environmental and biological systems.
基金supported by the National Natural Science Foundation of China(Nos.21801139,32101215,22007052)Natural Science Foundation of Jiangsu Province(Nos.BK20180942,BK20190917)。
文摘α-Cyanostilbene(CS)based organic luminescent materials with eficient electrical conductivity,aggregation-induced enhanced emission,and controllable multi-colour emission properties,have been aroused wide attention by scientists over the past few years.Self-assembly of cS-motif in aqueous me-dia refers to an environment-friendly method for preparing luminescent materials.However,it is still challenging to control the intrinsic hydrophobic properties of the organic components in aqueous media.In this study,an amphiphilic dicyanostilbene-functionalized thiophene(ACSTP)derivative was synthe-sized.Z-AcSTP was identified to dissolve in different organic solvents,accompanied with strong and tun-able fluorescence emission.However,when Z-AcSTP was dispersed in water,it was self-assembled into nanofibers,and the fluorescence was red shifted,accompanied with sharp decrease of intensity com-pared with that in DMSO.Furthermore,Z-form of ACSTP to its E-form under 365 nm irradiation led to the morphology transformation from nanofibers to nanosheets.Notably,upon addition of water-soluble pillar[5]arene(wP5),the nanofibers were transformed into fluorescent hollow particles due to the host-guest interactions between the pyridinium group and WP5 and the obtained fluorescent particles can be further applied in living cell imaging.
基金supported by the National Natural Science Foundation of China(Nos.32101215 and 22007052)the Natural Science Foundation of Nantong City(No.MS12021079).
文摘Synthesis and functionalization of novel macrocyclic host molecules are important topics in supramolecular chemistry.In this work,the first amphiphilic[2]biphenyl-extended pillar[6]arene(AM-[2]BP-ExP6)was designed and synthesized with poly(ethylene glycol)chains as the hydrophilic tails and a rigid cavity as the hydrophobic core.Due to its amphiphilic nature,AM-[2]BP-ExP6 could self-assemble to stable fibers in water.What’s more,AM-[2]BP-ExP6 could associate with quaternary ammonium modified tetraphenylethylene guest(QTPE)to form a 2:1 host-guest complex,accompanied by significant enhanced fluorescence.Interestingly,different like AM-[2]BP-ExP6,AM-[2]BP-ExP6⊃QTPE host-guest complex selfassembled into fluorescent particles with diameter about 310 nm,the obtained fluorescent particles can be further employed in living cell imaging.
文摘Polysaccharide-rich plant cell walls are important biomaterials that underpin plant growth, are major repositories for photosynthetically accumulated carbon, and, in addition, impact greatly on the human use of plants. Land plant cell walls contain in the region of a dozen major polysaccharide structures that are mostly encompassed by cellulose, hemicelluloses, and pectic polysaccharides. During the evolution of land plants, polysaccharide diversification appears to have largely involved structural elaboration and diversification within these polysaccharide groups. Cell wall chemistry is well advanced and a current phase of cell wall science is aimed at placing the complex polysaccharide chemistry in cellular contexts and developing a detailed understanding of cell wall biology. Imaging cell wall glycomes is a challenging area but recent developments in the establishment of cell wall molecular probe panels and their use in high throughput procedures are leading to rapid advances in the molecular understanding of the spatial heterogeneity of individual cell walls and also cell wall differences at taxonomic levels. The challenge now is to integrate this knowledge of cell wall heterogeneity with an understanding of the molecular and physiological mechanisms that underpin cell wall properties and functions.
基金Project supported by the Swiss National Science Foundation
文摘Trivalent lanthanide ions display fascinating optical properties. The discovery of the corresponding elements and their first industrial uses were intimately linked to their optical properties. This relationship has been kept alive until today when many high-technology applications of lanthanide-containing materials such as energy-saving lighting devices, displays, optical fibers and amplifiers, lasers, responsive luminescent stains for biomedical analyses and in cellulo sensing and imaging, heavily rely on the brilliant and pure-color emission of lanthanide ions. In this review we first outlined the basics of lanthanide luminescence with emphasis on f-f transitions, the sensitization mechanisms, and the assessment of the luminescence efficiency of lanthanide-containing emissive molecular edifices. Emphasis was then put on two fast developing aspects of lanthanide luminescence： materials for telecommunications and light emitting diodes, and biomedical imaging and sensing. Recent advances in NIR-emitting materials for plastic amplifiers and waveguides were described, together with the main solutions brought by researchers to minimize non-radiative deactivation of excited states. The demonstration in 1999 that erbium tris（8-hydroxyquinolinate） displayed a bright green emission suitable for organic light emitting diodes （OLEDs） was followed by realizing that in OLEDs, 25% of the excitation energy leads to singlet states and 75% to triplet states. Since lanthanide ions are good triplet quenchers, they now also play a key role in the development of these lighting devices. Luminescence analyses of biological molecules are among the most sensitive analytical techniques known. The long lifetime of the lanthanide excited states allows time-resolved spectroscopy to be used, suppressing the sample autofluorescence and reaching very low detection limits. Not only visible lanthanide sensors are now ubiquitously provided in medical diagnosis and in cell imaging, but the feasibility of using NIR emission of ions such
