随着污染物的排放日益增多,环境问题备受关注.金属离子作为重要的污染来源之一,对人们生活造成了极大的影响,并可能引发各种疾病.因此,快速灵敏地检测环境中的金属离子尤为重要.含有各种检测基团的有机染料通过表观颜色和荧光的变化,实...随着污染物的排放日益增多,环境问题备受关注.金属离子作为重要的污染来源之一,对人们生活造成了极大的影响,并可能引发各种疾病.因此,快速灵敏地检测环境中的金属离子尤为重要.含有各种检测基团的有机染料通过表观颜色和荧光的变化,实现了对金属离子特异、灵敏的检测,表现出巨大的潜力.本文基于有机荧光分子的特殊光物理性质与共轭结构,综述了近年来有机金属离子探针常用的检测机理.所涉及的检测机理主要有光诱导电子转移(photoinduced electron transfer,PET)机理、分子内电荷转移(intramolecular charge transfer,ICT)机理、荧光共振能量转移(fluorescence resonance energy transfer,FRET)机理、跨键能量转移(through-bond energy transfer,TBET)机理、分子的聚集-解聚以及π共轭结构重排.此外,还对金属离子与探针之间的相互作用,以及探针的基本设计思路进行详细的讨论,并在目前研究的基础上对其发展前景进行展望.展开更多
Phototheranostics provide a safe,effective,and noninvasive way for the diagnosis and treatment of contemporary diseases,and organic dyes play a vital role.For example,chemical modification endowed dyes with powerful r...Phototheranostics provide a safe,effective,and noninvasive way for the diagnosis and treatment of contemporary diseases,and organic dyes play a vital role.For example,chemical modification endowed dyes with powerful reactive oxygen species or heat generation ability,favoring for photodynamic therapy and photoacoustic(PA)imaging guided photothermal therapy(PTT)of serious diseases.Therefore,photophysical properties manipulation of dyes has become the focus in current dye chemistry research.The development of aggregate science has made great effort to solve this problem.In recent years,a large number of studies have focused on molecular aggregation behavior and its effect on photophysical performance.The most famous example is the discovery of aggregation-induced emission(AIE)phenomenon.Based on AIE theory,more theories for revealing the relationship between molecular aggregation behavior and photophysical properties were proposed and elucidated.The photophysical property changes caused by dye aggregation have become a unique discipline,guiding the development of molecular science and material science.With the help of molecular self-assembly,controllable aggregation of dyes can be realized,and stable nano-theranostic reagents can be obtained.Furthermore,constructing dye assemblies with various photophysical properties will greatly reduce the cost of theranostic reagents,thus,expanding biomedical applications of organic dyes.Therefore,this review focuses on the photophysical characteristic changes caused by dye aggregation and their biological applications including,fluorescence/phosphorescence/PA imaging as well as photodynamic and PTT.This review will provide guidance for the design of organic dyes,the development of controllable aggregation methods,and the construction of multifunctional phototheranostic reagents.展开更多
Self-assembly of dyes has become a flexible strategy to modulate their photophysical properties.H-aggregates show great potential to increase heat generation,while the precise designing of H-aggregates as efficient ph...Self-assembly of dyes has become a flexible strategy to modulate their photophysical properties.H-aggregates show great potential to increase heat generation,while the precise designing of H-aggregates as efficient photothermal agents is still challenging.Herein,a quinoline cyanine(QCy)is developed for constructing stable H-aggregated nanoparticles(NPs)to significantly enhance photostability and photothermal conversion efficiency(PCE).With symmetrical rigid planar quinoline structures,QCy has a small and symmetrical dihedral angle(11.9°),which ensures excellent molecular planarity.In aqueous solution,the planar QCy can form closeπ–πmolecular stacking,and fast self-assemble into stable H-aggregates even at low concentrations(1×10−7 M).QCy H-aggregates are sphere-like NPs(QCy NPs)with an average diameter of 120 nm and exhibit high stability.H-aggregation of QCy significantly enhances PCE from 20.1%(non-H-aggregated QCy)to 63.8%(QCy NPs).In addition,the positive charge of quaternarized quinoline provides mitochondrial anchoring ability,which further enhances the photothermal effect.With high PCE and tumor accumulation,QCy NPs in low-doses have been successfully used in photoacoustic imaging-guided tumor photothermal therapy.展开更多
Hydrophilic dendrimers, especially poly（amidoamine）（PAMAM） dendrimers are widely applied in modifying fluorescent dyes to endow them with water solubility and biocompatibility for biologic fluorescence imaging.Com...Hydrophilic dendrimers, especially poly（amidoamine）（PAMAM） dendrimers are widely applied in modifying fluorescent dyes to endow them with water solubility and biocompatibility for biologic fluorescence imaging.Common preparation strategies of fluorescent dendrimers including encapsulating dyes or attaching dyes at periphery of dendrimers might cause uncertain constituent and lower biocompatibility. Here, we have developed a series of watersoluble fluorescent dendrimers with dye as core and fanshaped PAMAM as arms. Carboxylated perylene bisimides（PBI） dye and squarylium indocyanine（SICy） dye were conjugated with PAMAM dendrons by amidation to obtain a series of fluorescent dendrimers with enhanced water-solubility. Two PBI based dendrimers（PBI-G2.5 and PBI-G1.5）were chosen as model compounds for further optical, selfassembly and biological studies. In aqueous environment,PBI-G2.5 exhibited strong fluorescence, small size（~30 nm）and slightly positive surface charge（~2.46 mV）, which are ideal for biomedical applications. In vitro assays demonstrated that PBI-G2.5 nanoparticles accumulated in the cytoplasm of He La cells with rapid cellular uptake. The strong fluorescence in He La cells remained for over 48 h. To conclude, our study provides an effective strategy for preparing water-soluble fluorescent dendrimers towards long-term live cell imaging.展开更多
文摘随着污染物的排放日益增多,环境问题备受关注.金属离子作为重要的污染来源之一,对人们生活造成了极大的影响,并可能引发各种疾病.因此,快速灵敏地检测环境中的金属离子尤为重要.含有各种检测基团的有机染料通过表观颜色和荧光的变化,实现了对金属离子特异、灵敏的检测,表现出巨大的潜力.本文基于有机荧光分子的特殊光物理性质与共轭结构,综述了近年来有机金属离子探针常用的检测机理.所涉及的检测机理主要有光诱导电子转移(photoinduced electron transfer,PET)机理、分子内电荷转移(intramolecular charge transfer,ICT)机理、荧光共振能量转移(fluorescence resonance energy transfer,FRET)机理、跨键能量转移(through-bond energy transfer,TBET)机理、分子的聚集-解聚以及π共轭结构重排.此外,还对金属离子与探针之间的相互作用,以及探针的基本设计思路进行详细的讨论,并在目前研究的基础上对其发展前景进行展望.
基金National Natural Science Foundation of China,Grant/Award Numbers:51903014,21774007Beijing Natural Science Foundation,Grant/Award Number:2202043China Postdoctoral Science Foundation,Grant/Award Numbers:2020M680310,2020M680309。
文摘Phototheranostics provide a safe,effective,and noninvasive way for the diagnosis and treatment of contemporary diseases,and organic dyes play a vital role.For example,chemical modification endowed dyes with powerful reactive oxygen species or heat generation ability,favoring for photodynamic therapy and photoacoustic(PA)imaging guided photothermal therapy(PTT)of serious diseases.Therefore,photophysical properties manipulation of dyes has become the focus in current dye chemistry research.The development of aggregate science has made great effort to solve this problem.In recent years,a large number of studies have focused on molecular aggregation behavior and its effect on photophysical performance.The most famous example is the discovery of aggregation-induced emission(AIE)phenomenon.Based on AIE theory,more theories for revealing the relationship between molecular aggregation behavior and photophysical properties were proposed and elucidated.The photophysical property changes caused by dye aggregation have become a unique discipline,guiding the development of molecular science and material science.With the help of molecular self-assembly,controllable aggregation of dyes can be realized,and stable nano-theranostic reagents can be obtained.Furthermore,constructing dye assemblies with various photophysical properties will greatly reduce the cost of theranostic reagents,thus,expanding biomedical applications of organic dyes.Therefore,this review focuses on the photophysical characteristic changes caused by dye aggregation and their biological applications including,fluorescence/phosphorescence/PA imaging as well as photodynamic and PTT.This review will provide guidance for the design of organic dyes,the development of controllable aggregation methods,and the construction of multifunctional phototheranostic reagents.
基金This work was financially supported by the National Natural Science Foundation of China(Nos.52130309 and 51903014)Beijing Natural Science Foundation(No.2202043)Changzhou Sci&Tech Program(No.CJ20210041).
文摘Self-assembly of dyes has become a flexible strategy to modulate their photophysical properties.H-aggregates show great potential to increase heat generation,while the precise designing of H-aggregates as efficient photothermal agents is still challenging.Herein,a quinoline cyanine(QCy)is developed for constructing stable H-aggregated nanoparticles(NPs)to significantly enhance photostability and photothermal conversion efficiency(PCE).With symmetrical rigid planar quinoline structures,QCy has a small and symmetrical dihedral angle(11.9°),which ensures excellent molecular planarity.In aqueous solution,the planar QCy can form closeπ–πmolecular stacking,and fast self-assemble into stable H-aggregates even at low concentrations(1×10−7 M).QCy H-aggregates are sphere-like NPs(QCy NPs)with an average diameter of 120 nm and exhibit high stability.H-aggregation of QCy significantly enhances PCE from 20.1%(non-H-aggregated QCy)to 63.8%(QCy NPs).In addition,the positive charge of quaternarized quinoline provides mitochondrial anchoring ability,which further enhances the photothermal effect.With high PCE and tumor accumulation,QCy NPs in low-doses have been successfully used in photoacoustic imaging-guided tumor photothermal therapy.
基金financially supported by the National Natural Science Foundation of China (21774007, 21574009 and 51521062)the Higher Education and High-quality and World-class Universities (PY201605)
文摘Hydrophilic dendrimers, especially poly（amidoamine）（PAMAM） dendrimers are widely applied in modifying fluorescent dyes to endow them with water solubility and biocompatibility for biologic fluorescence imaging.Common preparation strategies of fluorescent dendrimers including encapsulating dyes or attaching dyes at periphery of dendrimers might cause uncertain constituent and lower biocompatibility. Here, we have developed a series of watersoluble fluorescent dendrimers with dye as core and fanshaped PAMAM as arms. Carboxylated perylene bisimides（PBI） dye and squarylium indocyanine（SICy） dye were conjugated with PAMAM dendrons by amidation to obtain a series of fluorescent dendrimers with enhanced water-solubility. Two PBI based dendrimers（PBI-G2.5 and PBI-G1.5）were chosen as model compounds for further optical, selfassembly and biological studies. In aqueous environment,PBI-G2.5 exhibited strong fluorescence, small size（~30 nm）and slightly positive surface charge（~2.46 mV）, which are ideal for biomedical applications. In vitro assays demonstrated that PBI-G2.5 nanoparticles accumulated in the cytoplasm of He La cells with rapid cellular uptake. The strong fluorescence in He La cells remained for over 48 h. To conclude, our study provides an effective strategy for preparing water-soluble fluorescent dendrimers towards long-term live cell imaging.
