The demand for enhanced optical properties in advanced fluorescence technologies has driven research into the structure-property relationship of fluorophores.In this paper,we use naphthalene fluorophores Na DC-Aze and...The demand for enhanced optical properties in advanced fluorescence technologies has driven research into the structure-property relationship of fluorophores.In this paper,we use naphthalene fluorophores Na DC-Aze and PhDO-Aze as a case study to emphasize the pivotal role of cross conjugation in tuning the optical structure-property relationship.Na DC-Aze and PhDO-Aze,formed by hybridizing two distinct conjugated systems in a single naphthalene molecule,exhibit spectral characteristics from both conjugated systems.Experimental data and theoretical calculations demonstrate the coexistence of two electron-delocalization systems in a cross-conjugation manner in both Na DC-Aze and PhDO-Aze.The cross-conjugation fluorophores exhibit high brightness,large Stokes shift,and a broad absorption wavelength range by combining distinct spectral properties from its parent fluorophores.These spectral properties will be advantageous for certain applications(i.e.,panchromatic absorption in organic solar cells,and fluorophores compatible with a wide range of excitation wavelengths).展开更多
Environment-sensitive fluorescent probes are commonly utilized in various fields,including fluorescence sensing and imaging.This paper describes the synthesis and photophysical properties of a novel class of solvatoch...Environment-sensitive fluorescent probes are commonly utilized in various fields,including fluorescence sensing and imaging.This paper describes the synthesis and photophysical properties of a novel class of solvatochromic fluorophores that incorporate biisoindolylidene as the core backbone.This study investigates the structure-property relationships of these newly developed fluorophores.The central biisoindolylidene acts as an efficient electron acceptor,and by modifying the aryl ring substituent at the 3,3 position,the photophysical properties of the fluorophores can be significantly enhanced,particularly in terms of photoluminescence quantum efficiency.Furthermore,when an electron-donor group replaces the aryl ring at the 3,3 position,intriguing solvatochromic behavior is observed.This leads to a red-shift in the maximum emission wavelength and an increase in the Stokes shift with increasing solvent polarity.In solvent dimethyl sulfoxide(DMSO),the maximum emission wavelength can reach up to 750 nm,with a Stokes shift of approximately 150 nm.Finally,the potential application of the fluorophore in the detection of volatile acids is explored in a preliminary manner.展开更多
In the second near-infrared channel(NIR-II, 1000–1700 nm), organic and inorganic fluorophores are designed with superior chemical/optical properties to provide real-time information with deeper penetration depth and ...In the second near-infrared channel(NIR-II, 1000–1700 nm), organic and inorganic fluorophores are designed with superior chemical/optical properties to provide real-time information with deeper penetration depth and higher resolution owing to the innate lower light scattering and absorption of the NIR-II imaging than conventional optical imaging. Among them, the small-molecule based fluorophores have been highlighted due to their desirable biocompatibility and favorable pharmacokinetics. In this review, we introduced the latest research progress of the rational design of small-molecule NIR-II fluorophores and their impressively biological applications including the NIR-II signal imaging,multimodal imaging and theranostic.展开更多
Phototheranostics have attracted tremendous attention in cancer diagnosis and treatment because of the noninvasiveness and promising effectiveness.Developing advanced phototheranostic agents with long emission wavelen...Phototheranostics have attracted tremendous attention in cancer diagnosis and treatment because of the noninvasiveness and promising effectiveness.Developing advanced phototheranostic agents with long emission wavelength,excellent biocompatibility,great tumor-targeting capability,and efficient therapeutic effect is highly desirable.However,the mutual constraint between imaging and therapeutic functions usually hinders their wide applications in biomedical field.To balance this contradiction,we herein rationally designed and synthesized three novel tumor-targeted NIR-Ⅱ probes(QR-2PEG_(321),QR-2PEG_(1000),and QR-2PEG_(5000)) by conjugating three different chain lengths of PEG onto an integrin α_(v)β_(3)-targeted NIR-Ⅱ heptamethine cyanine fluorophore,respectively.In virtue of the essential amphiphilic characteristics of PEG polymers,these probes display various degree of aggregation in aqueous buffer accompanying with differential NIR-Ⅱ imaging and photothermal(PTT) therapeutic performance.Both in vitro and in vivo results have demonstrated that probe QR-2PEG_(5000) has the best NIR-Ⅱ imaging performance with prominent renal clearance,whereas QR-2PEG_(321)possesses excellent photoacoustic signal as well as PTT effect,which undoubtedly provides a promising toolbox for tumor diagnosis and therapy.We thus envision that these synthesized probes have great potential to be explored as a toolkit for precise diagnosis and treatment of malignant tumors.展开更多
Hyperthermia (42-44℃) and photosensitizing therapy can destroy S180 tumor cells,reducemalignant ascites and prolong the survival times of mice with carcinomas.The highestcurative effect was observed when using a comb...Hyperthermia (42-44℃) and photosensitizing therapy can destroy S180 tumor cells,reducemalignant ascites and prolong the survival times of mice with carcinomas.The highestcurative effect was observed when using a combination of the two treatments.Heating to44℃ has a greater destructive effect on tumor cells than has heating to 42℃.The resultsshow that this is due to a synergistic interaction between these two treatments.The fluores-cence spectrum of S180 cells was determined before and alter treatment,and the indicationwas that the synergistic effect is probably related to a new fluorescence product;the greaterthe intensity of the new fluorescence、the more marked the synergy of hyperthermia andphotosensitizing therapy.The maximum emission wavelength was 460nm (excitation wave-length 370nm).展开更多
In citric acid-based carbon dots,molecular fluorophore contributes greatly to the fluorescence emission.In this paper,the nitrogen and sulfur co-doped carbon dots(N,S-CDs)were prepared,and an independent sulfur source...In citric acid-based carbon dots,molecular fluorophore contributes greatly to the fluorescence emission.In this paper,the nitrogen and sulfur co-doped carbon dots(N,S-CDs)were prepared,and an independent sulfur source is selected to achieve the doping controllability.The influence of sulfur doping on the molecular fluorophore was systematically studied.The introduction of sulfur atoms may promote the formation of molecular fluorophore due to the increased nitrogen content in CDs.The addition surface states containing sulfur were produced,and S element exists as-SO_(3),and-SO_(4)groups.Appreciate ratio of nitrogen and sulfur sources can improve the fluorescence emission.The photoluminescence quantum yields(PLQY)is increased from 56.4%of the single N-doping CDs to 63.4%of double-doping CDs,which ascribes to the synergistic effect of molecular fluorophores and surface states.The sensitivity of fluorescence to pH response and various metal ions was also explored.展开更多
Folded or nonfolded fluorophores incorporating naphthalene were synthesized and characterized by steady state fluorescence technique.Paraquat as an excellent quenching reagent quenched the fluorescence of Nel6 or nDs(...Folded or nonfolded fluorophores incorporating naphthalene were synthesized and characterized by steady state fluorescence technique.Paraquat as an excellent quenching reagent quenched the fluorescence of Nel6 or nDs(n = 1-4) driven by charge transfer.Under aggregation of nDs,α-CD did not quench the fluorescence of 1D.At lower concentration,the quenching tendency ofα-CD against nDs is 2D>3D>4D,while at higher concentration,the tendency is 2D<3D<4D.α-CD showed the selective recognition on its flu...展开更多
Fluorescent materials that respond to multiple stimuli have broad applications ranging from sensing and bioimaging to information encryption.Herein,we report the design and synthesis of a single-fluorophorebased amphi...Fluorescent materials that respond to multiple stimuli have broad applications ranging from sensing and bioimaging to information encryption.Herein,we report the design and synthesis of a single-fluorophorebased amphiphile DCSO,which shows temperature-,solvent-,humidity-,and radiation-dependent fluorescence.DCSO consists of a dicyanostilbene(DCS)group as a rigid hydrophobic core with oligo(ethylene glycol)(OEG)chains at both ends as a flexible hydrophilic periphery.The DCS group acts as a highly efficient fluorophore,while the OEG chain endows the molecule with thermo-responsiveness.Fluorescent colors can vary from blue to green to yellow in response to external stimuli.On the basis of light radiation,we demonstrate that this system can be applied to time-dependent information encryption,in which the correct information can only be read at a specific time under irradiation.This work further demonstrates the usefulness and application of single-fluorophore-based luminescent materials with multiple stimuli-responsive functions.展开更多
The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanu...The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanuric chloride in the presence of Na2CO3 followed by the addition of trityl aniline. Solution and solid state fluorescence demonstrated a strong blue/purple emission centered at 450 nm. 1H-NMR spectroscopy, mass spectrometry analysis, elemental analysis, and DOSY-NMR were used for the characterization of the fluorophore.展开更多
Emission quenching resulting from fluorophore aggregation has long been a significant challenge in optimizing emission-based technologies,such as fluorescence imaging and optoelectronic devices.Alleviating this quench...Emission quenching resulting from fluorophore aggregation has long been a significant challenge in optimizing emission-based technologies,such as fluorescence imaging and optoelectronic devices.Alleviating this quenching in aggregates is crucial,yet progress is impeded by the limited understanding of the nature and impact of aggregates on emission.Here,we elucidate the critical role of dimeric aggregate(dimer)in alleviating second near-infrared(NIR-II,900-1700 nm)emission quenching from ring-fused fluorophore 4F for superior fluorescence imaging.Spectral decomposition and molecular dynamics simulations demonstrate the predominance of dimer populations in 4F aggregates.Notably,dimers exhibit significantly weaker emission but intense intermolecular nonradiative(interNR)decay compared to monomers,as demonstrated by ultrafast spectra and quantum calculation.Therefore,the predominant population of dimers with weak emission and pronounced interNR feature underlies the emission quenching in 4F aggregates.This discovery guides the preparation of ultrabright NIR-II 4F nanofluorophore(4F NP3s)by decreasing dimer populations,which show 5-fold greater NIR-II brightness than indocyanine green,enabling superior resolution in visualizing blood vessels.This work offers valuable insights into aggregation-caused quenching,with broad implications extending far beyond NIR-II fluorescence imaging.展开更多
Recent advancements in single-molecule biophysics have been driven by breakthroughs in advanced fluorescence microscopy techniques and the development of nextgeneration organic fluorophores.These cutting-edge fluoroph...Recent advancements in single-molecule biophysics have been driven by breakthroughs in advanced fluorescence microscopy techniques and the development of nextgeneration organic fluorophores.These cutting-edge fluorophores,coupled through tailored biolabeling strategies,offer single-molecule brightness,photostability,and phototunability(i.e.,photoswitchable,photoactivatable),contributing to enhancing spatial and temporal imaging resolution for studying biomolecular interactions and dynamics at single-event precision.This review examines the progress made over the past decade in the development of next-generation fluorophores,along with their site-specific labeling methods for proteins,nucleic acids,and biomolecular complexes.It also explores their applications in single-molecule fluorescencebased dynamic structural biology and super-resolution microscopy imaging.Furthermore,it examines ongoing efforts to address challenges associated with fluorophore photostability,photobleaching,and the integration of advanced photophysical and photochemical functionalities.The integration of state-of-the-art fluorophores with advanced labeling strategies aim to deliver complementary correlative data,holding promise for revolutionizing single-molecule biophysics by pushing the boundaries of temporal and spatial imaging resolution to unprecedented limits.展开更多
Creation of new fluorophores is important for understanding the structure-property relationship,by which the required optical properties are likely to be attained.Herein,through theory calculation,it is found that fur...Creation of new fluorophores is important for understanding the structure-property relationship,by which the required optical properties are likely to be attained.Herein,through theory calculation,it is found that furan-modified thiadiazolo quinoxaline acting as an electron acceptor can endow donor-acceptor-donor(D-A-D)type second near-infrared(NIR-Ⅱ)fluorophores with longer emission wavelength than the other thiadiazolo quinoxaline-based acceptors containing pyridine,pyrrole,thiophene,and phenyl groups,respectively.On the basis of this theoretical prediction,a D-A-D type NIR-Ⅱ fluorophore with 6,7-di(furan-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline(DFTQ)as the acceptor and dithieno[3,2-b:2′,3′-d]pyrrole(DTP)as the donor is designed and synthesized,and the aggregation-induced emission(AIE)function is further achieved by introducing the AIE units of tetraphenylethylene(TPE)and triphenylamine(TPA),respectively,totally forming three NIR-Ⅱ fluorophores DFTQ-DTP,DFTQ-DTPE,and DFTQ-DTPA.For biological applications,the fluorophores are encapsulated by amphiphilic DSPE-PEG2000 to generate water-dispersible nanoparticles(NPs).Almost the whole emission of each of the NPs falls into the NIR-Ⅱ spectral range,with part emission beyond 1300 nm.By using DFTQ-DTPA NPs as the contrast and photothermal therapy(PTT)agent,high-resolution in vivo fluorescence imaging is achieved in the greater than 1300 nm window,and their good performance in photoacoustic imaging and high tumor PTT efficacy in tumor-bearing mice are also demonstrated.Taken together,this work mainly provides a strong electron acceptor for constructing longemitting fluorophores,and by using the electron acceptor,a AIE fluorophore with desirable quantum yield(QY)and photothermal conversion efficienciy(PCE)is synthesized and demonstrated to be promising in fluorescence/photoacoustic imaging and PTT.展开更多
Molecular rotor-based fluorophores(RBFs)activate fluorescence upon increase of micro-viscosity,thus bearing a broad application promise in many fields.However,it remains a challenge to control how fluorescence of RBFs...Molecular rotor-based fluorophores(RBFs)activate fluorescence upon increase of micro-viscosity,thus bearing a broad application promise in many fields.However,it remains a challenge to control how fluorescence of RBFs responds to viscosity changes.Herein,we demonstrate that the formation and regulation of intramolecular hydrogen bonds in the excited state of RBFs could modulate their rotational barrier,leading to a rational control of how their fluorescence can be activated by micro-viscosity.Based on this strategy,a series of RBFs were developed based on 4-hydroxybenzylidene-imidazolinone(HBI)that span a wide range of viscosity sensitivity.Combined with the AggTag method that we previously reported,the varying viscosity sensitivity and emission spectra of these probes enabled a dualcolor imaging strategy that detects both protein oligomers and aggregates during the multistep aggregation process of proteins in live cells.In summary,our work indicates that installing intracellular excited state hydrogen bonds to RBFs allows for a rational control of rotational barrier,thus allow for a fine tune of their viscosity sensitivity.Beyond RBFs,we envision similar strategies can be applied to control the fluorogenic behavior of a large group of fluorophores whose emission is dependent on excited state rotational motion,including aggregation-induced emission fluorophores.展开更多
The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI ...The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI with NIR-II window excitation (1064nm/other wavelength beyond 1000nm) can afford deeper tissue penetration depth with high clarity due to the merits of suppressed photon scattering and diminished autofluorescence. In this review, we have summarized NIR-II window excitable/emissive organic/polymeric fluorophores recently developed. The characteristics of these fluorophores such as chemical structures and photophysical properties have also been critically discussed. Furthermore, the latest development of noninvasive in vivo FLI with NIR-II excitation was highlighted. The ideal imaging results emphasized the importance of NIR-II excitation of these fluorophores in enabling deep tissue penetration and high-resolution imaging. Finally, a perspective on the challenges and prospects of NIR-II excitable/emissive organic/polymeric fluorophores was also discussed. We expected this review will be served as a source of inspiration for researchers, stimulating the creation of novel NIR-II excitable fluorophores and fostering the development of bioimaging applications.展开更多
Fluorophores emitting in the second near-infrared window (NIR-II, 900–1700nm) allow for high-resolution deep-tissue bioimaging owing to minimal tissue scattering. Although J-aggregation offers a promising approach to...Fluorophores emitting in the second near-infrared window (NIR-II, 900–1700nm) allow for high-resolution deep-tissue bioimaging owing to minimal tissue scattering. Although J-aggregation offers a promising approach to developing long-wavelength emitters, the scarcity of J-type backbones and reliable design principles limits their application in biological imaging. Here, we introduce a strategy for engineering high-brightness NIR-II J-aggregated fluorophores by incorporating electron-withdrawing substituents into a fused-ring backbone. These substituents modulate the electrostatic potential (ESP) distribution across the conjugated backbone, reducing both electrostatic repulsion and intermolecular distance, which promotes ordered J-aggregation. As a result, Y8 aggregate (Y8 nanoparticles) exhibits an outstanding fluorescence quantum yield of up to 12.9% and strong near-infrared absorption in aqueous solution for high-performance NIR-II fluorescence imaging in vivo. This work not only presents a novel J-type backbone but also advances the understanding of the structure–property relationship critical to designing NIR-II J-aggregates.展开更多
Fluorescence imaging is a useful tool in the field of biomedical applications.However,its imaging capacity is limited by the depth of tissue that can be penetrated when using visible light(400-700 nm)or the first near...Fluorescence imaging is a useful tool in the field of biomedical applications.However,its imaging capacity is limited by the depth of tissue that can be penetrated when using visible light(400-700 nm)or the first near-infrared window(NIR-Ⅰ,700-900 nm).To overcome the problem,fluorescence imaging in the second near-infrared window(NIR-Ⅱ,1000-1700 nm)has been developed to reduce photon scattering,auto-absorption and tissue autofluorescence to achieve high spatiotemporal resolution and deep imaging penetration.The key to NIR-Ⅱimaging is obtaining and analyzing highly selective information from functional fluorophores that emit in the 1000-1700 nm range.With the rapid development of multidisciplinary research,various types of NIR-Ⅱfluorophores have been produced and used in non-invasive,real-time NIR-Ⅱbiomedical applications.This review summarizes some of the most prevalent NIR-Ⅱfluorophores and their synthesis,such as organic fluorophores(OFs),single-walled carbon nanotubes(SWCNTs),quantum dots(QDs),and rare-earth nanoparticles(RENPs).On this basis,we describe the applications of these fluorophores in biomedical fields,including bioimaging,biosensing,phototherapy and surgical navigation.Additionally,major challenges and prospects of NIR-Ⅱbiomedical application will be further explored.展开更多
Peroxisome research has been revolutionized by proteome studies combined with in vivo subcellular targeting analyses. Yellow and cyan fluorescent protein(YFP and CFP) are the classical fluorophores of plant peroxisome...Peroxisome research has been revolutionized by proteome studies combined with in vivo subcellular targeting analyses. Yellow and cyan fluorescent protein(YFP and CFP) are the classical fluorophores of plant peroxisome research. In the new transient expression system of Arabidopsis seedlings co-cultivated with Agrobacterium we detected the YFP fusion of one candidate protein in peroxisomes, but only upon co-transformation with the peroxisome marker, CFP-PTS1. The data suggested that the YFP fusion was directed to peroxisomes due to its weak heterodimerization ability with CFP-PTS1,allowing piggy-back import into peroxisomes. Indeed, if co-expressed with monomeric Cerulean-PTS1(mCer-PTS1),the YFP fusion was no longer matrix localized. We systematically investigated the occurrence and extent of dimerization-based piggy-back import for different fluorophore combinations in five major transient plant expression systems. In Arabidopsis seedlings and tobacco leaves both untagged YFP and monomeric Venus were imported into peroxisomes if co-expressed with CFP-PTS1 but not with mCer-PTS1. By contrast, piggy-back import of cytosolic proteins was not observed in Arabidopsis and tobacco protoplasts or in onion epidermal cells for any fluorophore combination at any time point. Based on these important results we formulate new guidelines for fluorophore usage and experimental design to guarantee reliable identification of novel plant peroxisomal proteins.展开更多
Phototheranostics integrates deep-tissue imaging with phototherapy(containing photothermal therapy and photodynamic therapy),holding great promise in early diagnosis and precision treatment of cancers.Recently,second ...Phototheranostics integrates deep-tissue imaging with phototherapy(containing photothermal therapy and photodynamic therapy),holding great promise in early diagnosis and precision treatment of cancers.Recently,second near-infrared(NIR-II)fluorescence imaging exhibits the merits of high accuracy and specificity,as well as real-time detection.Among the NIR-II fluorophores,organic small molecular fluorophores have shown superior properties in the biocompatibility,variable structure,and tunable emission wavelength than the inorganic NIR-II materials.What’s more,some small molecular fluorophores also display excellent cytotoxicity when illuminated with the NIR laser.This review summarizes the progress of small molecular NIR-II fluorophores with different central cores for cancer phototheranostics in the past few years,focusing on the molecular structures and phototheranostic performances.Furthermore,challenges and prospects of future development toward clinical translation are discussed.展开更多
Because of their important roles in cellular functions, life activities, drug screening, and disease treatment, the development of efficient methods for monitoring protein-ligand interaction is essential. In this stud...Because of their important roles in cellular functions, life activities, drug screening, and disease treatment, the development of efficient methods for monitoring protein-ligand interaction is essential. In this study, inspired by our previous studies on DNA conformation-selective fluorescent indicators, we developed a new sensing platform for monitoring protein-ligand interaction and detecting protein activity based on binding-mediated DNA protection and the dsDNA-lighted fluorophore, ethyl-4-[3,6-bis(1-methyl-4-vinylpyridium iodine)-9 H-carbazol-9-yl)] butanoate(EBCB). The ligand was purposefully linked to the 3?-terminal of a hairpin DNA probe to selectively bind with the target protein and protect the DNA from cleavage by exonuclease III. By virtue of EBCB's outstanding capacity to discriminate DNA conformation, the protein-ligand interaction could be effectively monitored through a fluorescence change in EBCB. A high fluorescence signal was detected when the hairpin DNA was protected in the presence of the target protein, whereas a much lower signal was observed in the presence of nontarget proteins.Our results demonstrated that the proposed strategy had high potential, such as high selectivity and relatively high sensitivity, for monitoring protein-ligand interaction and detecting protein activity. We believe these results will pave the way for applying dsDNA-lighted fluorophore EBCB as an effective signal transducer for DNA conformation transformation-mediated biochemical sensing.展开更多
Here we report the use of a Langmuir isotherm model to analyze and better understand the dynamic adsorption and desorption behavior of single fluorophore molecules at the surface of a hydrogen nanobubble supported on ...Here we report the use of a Langmuir isotherm model to analyze and better understand the dynamic adsorption and desorption behavior of single fluorophore molecules at the surface of a hydrogen nanobubble supported on an indium tin oxide(ITO)electrode.Three rhodamine dyes,rhodamine 110(R110,positively charged),rhodamine 6G(R6G,positively charged),and sulforhodamine G(SRG,negatively charged)were chosen for this study.The use of the Langmuir isotherm model allows us to determine the equilibrium constant and the rate constants for the adsorption and desorption processes.Of the three fluorophores used in this study,SRG was found to have the greatest equilibrium constant.No significant potential dependence was observed on the adsorption characteristics,which suggests the nanobubble size,geometry,and surface properties are relatively constant within the range of potentials used in this study.Our results suggest that the use of the Langmuir isotherm model is a valid and useful means for probing and better understanding the unique adsorption behavior of fluorophores at surface-supported nanobubbles.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22225806,22078314,21908216,22378385)Dalian Institute of Chemical Physics(Nos.DICPI202142,DICPI202436)+1 种基金Agency for Science,Technology and Research(No.A*STAR,Singapore)under its Advanced Manufacturing and Engineering Program(No.A2083c0051)SUTD Kickstarter Initiative(No.SKI 2021_03_10)。
文摘The demand for enhanced optical properties in advanced fluorescence technologies has driven research into the structure-property relationship of fluorophores.In this paper,we use naphthalene fluorophores Na DC-Aze and PhDO-Aze as a case study to emphasize the pivotal role of cross conjugation in tuning the optical structure-property relationship.Na DC-Aze and PhDO-Aze,formed by hybridizing two distinct conjugated systems in a single naphthalene molecule,exhibit spectral characteristics from both conjugated systems.Experimental data and theoretical calculations demonstrate the coexistence of two electron-delocalization systems in a cross-conjugation manner in both Na DC-Aze and PhDO-Aze.The cross-conjugation fluorophores exhibit high brightness,large Stokes shift,and a broad absorption wavelength range by combining distinct spectral properties from its parent fluorophores.These spectral properties will be advantageous for certain applications(i.e.,panchromatic absorption in organic solar cells,and fluorophores compatible with a wide range of excitation wavelengths).
基金supported by the National Natural Science Foundation of China(Nos.22225107,22301302)。
文摘Environment-sensitive fluorescent probes are commonly utilized in various fields,including fluorescence sensing and imaging.This paper describes the synthesis and photophysical properties of a novel class of solvatochromic fluorophores that incorporate biisoindolylidene as the core backbone.This study investigates the structure-property relationships of these newly developed fluorophores.The central biisoindolylidene acts as an efficient electron acceptor,and by modifying the aryl ring substituent at the 3,3 position,the photophysical properties of the fluorophores can be significantly enhanced,particularly in terms of photoluminescence quantum efficiency.Furthermore,when an electron-donor group replaces the aryl ring at the 3,3 position,intriguing solvatochromic behavior is observed.This leads to a red-shift in the maximum emission wavelength and an increase in the Stokes shift with increasing solvent polarity.In solvent dimethyl sulfoxide(DMSO),the maximum emission wavelength can reach up to 750 nm,with a Stokes shift of approximately 150 nm.Finally,the potential application of the fluorophore in the detection of volatile acids is explored in a preliminary manner.
基金partially supported by grants from NKR&DPC (No. 2016YFD0200902)National Natural Science Foundation of China (No. 21708012)+3 种基金111 Project (No. B17019)NSFHP (No. 2017CFB151)self-determined research funds of CCNU from the colleges, basic research and operation of MOE for the Central Universities (No. 110030106190234)Wuhan Morning Light Plan of Youth Science and Technology (No. 201705304010321)
文摘In the second near-infrared channel(NIR-II, 1000–1700 nm), organic and inorganic fluorophores are designed with superior chemical/optical properties to provide real-time information with deeper penetration depth and higher resolution owing to the innate lower light scattering and absorption of the NIR-II imaging than conventional optical imaging. Among them, the small-molecule based fluorophores have been highlighted due to their desirable biocompatibility and favorable pharmacokinetics. In this review, we introduced the latest research progress of the rational design of small-molecule NIR-II fluorophores and their impressively biological applications including the NIR-II signal imaging,multimodal imaging and theranostic.
基金financial support from the Training Program of the Major Research Plan of the National Natural Science Foundation of China (No. 91959123)National Natural Science Foundation of China (No. 22077092)+2 种基金Key Research and Development Program of Social Development of Jiangsu Province (No. BE2018655)the Open Project Program of the State Key Laboratory of Radiation Medicine and Protection (Nos. GZK1202132, GZK1202140 and GZK1202017)funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Phototheranostics have attracted tremendous attention in cancer diagnosis and treatment because of the noninvasiveness and promising effectiveness.Developing advanced phototheranostic agents with long emission wavelength,excellent biocompatibility,great tumor-targeting capability,and efficient therapeutic effect is highly desirable.However,the mutual constraint between imaging and therapeutic functions usually hinders their wide applications in biomedical field.To balance this contradiction,we herein rationally designed and synthesized three novel tumor-targeted NIR-Ⅱ probes(QR-2PEG_(321),QR-2PEG_(1000),and QR-2PEG_(5000)) by conjugating three different chain lengths of PEG onto an integrin α_(v)β_(3)-targeted NIR-Ⅱ heptamethine cyanine fluorophore,respectively.In virtue of the essential amphiphilic characteristics of PEG polymers,these probes display various degree of aggregation in aqueous buffer accompanying with differential NIR-Ⅱ imaging and photothermal(PTT) therapeutic performance.Both in vitro and in vivo results have demonstrated that probe QR-2PEG_(5000) has the best NIR-Ⅱ imaging performance with prominent renal clearance,whereas QR-2PEG_(321)possesses excellent photoacoustic signal as well as PTT effect,which undoubtedly provides a promising toolbox for tumor diagnosis and therapy.We thus envision that these synthesized probes have great potential to be explored as a toolkit for precise diagnosis and treatment of malignant tumors.
文摘Hyperthermia (42-44℃) and photosensitizing therapy can destroy S180 tumor cells,reducemalignant ascites and prolong the survival times of mice with carcinomas.The highestcurative effect was observed when using a combination of the two treatments.Heating to44℃ has a greater destructive effect on tumor cells than has heating to 42℃.The resultsshow that this is due to a synergistic interaction between these two treatments.The fluores-cence spectrum of S180 cells was determined before and alter treatment,and the indicationwas that the synergistic effect is probably related to a new fluorescence product;the greaterthe intensity of the new fluorescence、the more marked the synergy of hyperthermia andphotosensitizing therapy.The maximum emission wavelength was 460nm (excitation wave-length 370nm).
基金Project supported by the National Natural Science Foundation of China(Grant No.51571085)the Key Scientific Research Projects of Colleges and Universities in Henan Province,China(Grant No.20A430015).
文摘In citric acid-based carbon dots,molecular fluorophore contributes greatly to the fluorescence emission.In this paper,the nitrogen and sulfur co-doped carbon dots(N,S-CDs)were prepared,and an independent sulfur source is selected to achieve the doping controllability.The influence of sulfur doping on the molecular fluorophore was systematically studied.The introduction of sulfur atoms may promote the formation of molecular fluorophore due to the increased nitrogen content in CDs.The addition surface states containing sulfur were produced,and S element exists as-SO_(3),and-SO_(4)groups.Appreciate ratio of nitrogen and sulfur sources can improve the fluorescence emission.The photoluminescence quantum yields(PLQY)is increased from 56.4%of the single N-doping CDs to 63.4%of double-doping CDs,which ascribes to the synergistic effect of molecular fluorophores and surface states.The sensitivity of fluorescence to pH response and various metal ions was also explored.
基金the Natural Science Foundation of China(No.20172069) for financial support
文摘Folded or nonfolded fluorophores incorporating naphthalene were synthesized and characterized by steady state fluorescence technique.Paraquat as an excellent quenching reagent quenched the fluorescence of Nel6 or nDs(n = 1-4) driven by charge transfer.Under aggregation of nDs,α-CD did not quench the fluorescence of 1D.At lower concentration,the quenching tendency ofα-CD against nDs is 2D>3D>4D,while at higher concentration,the tendency is 2D<3D<4D.α-CD showed the selective recognition on its flu...
基金supported by the National Natural Science Foundation of China(No.21702020)partially supported by the Starry Night Science Fund of Zhejiang University Shanghai Institute for Advanced Study(No.SN-ZJU-SIAS-006).
文摘Fluorescent materials that respond to multiple stimuli have broad applications ranging from sensing and bioimaging to information encryption.Herein,we report the design and synthesis of a single-fluorophorebased amphiphile DCSO,which shows temperature-,solvent-,humidity-,and radiation-dependent fluorescence.DCSO consists of a dicyanostilbene(DCS)group as a rigid hydrophobic core with oligo(ethylene glycol)(OEG)chains at both ends as a flexible hydrophilic periphery.The DCS group acts as a highly efficient fluorophore,while the OEG chain endows the molecule with thermo-responsiveness.Fluorescent colors can vary from blue to green to yellow in response to external stimuli.On the basis of light radiation,we demonstrate that this system can be applied to time-dependent information encryption,in which the correct information can only be read at a specific time under irradiation.This work further demonstrates the usefulness and application of single-fluorophore-based luminescent materials with multiple stimuli-responsive functions.
文摘The synthesis and characterization of a novel fluorophore(1), with potential application as an optical brightener are reported. This compound was prepared by reacting 4,4-diaminostilbene-2,2-disulfonic acid with cyanuric chloride in the presence of Na2CO3 followed by the addition of trityl aniline. Solution and solid state fluorescence demonstrated a strong blue/purple emission centered at 450 nm. 1H-NMR spectroscopy, mass spectrometry analysis, elemental analysis, and DOSY-NMR were used for the characterization of the fluorophore.
基金support by the National Natural Science Foundation of China(No.62175201,62288102,and 52373142)the Fundamental Research Funds for the Central Universities,and the open research fund of State Key Laboratory of Organic Electronics and Information Displays.
文摘Emission quenching resulting from fluorophore aggregation has long been a significant challenge in optimizing emission-based technologies,such as fluorescence imaging and optoelectronic devices.Alleviating this quenching in aggregates is crucial,yet progress is impeded by the limited understanding of the nature and impact of aggregates on emission.Here,we elucidate the critical role of dimeric aggregate(dimer)in alleviating second near-infrared(NIR-II,900-1700 nm)emission quenching from ring-fused fluorophore 4F for superior fluorescence imaging.Spectral decomposition and molecular dynamics simulations demonstrate the predominance of dimer populations in 4F aggregates.Notably,dimers exhibit significantly weaker emission but intense intermolecular nonradiative(interNR)decay compared to monomers,as demonstrated by ultrafast spectra and quantum calculation.Therefore,the predominant population of dimers with weak emission and pronounced interNR feature underlies the emission quenching in 4F aggregates.This discovery guides the preparation of ultrabright NIR-II 4F nanofluorophore(4F NP3s)by decreasing dimer populations,which show 5-fold greater NIR-II brightness than indocyanine green,enabling superior resolution in visualizing blood vessels.This work offers valuable insights into aggregation-caused quenching,with broad implications extending far beyond NIR-II fluorescence imaging.
基金financial support from the National Natural Science Foundation of China(No.22374075)the Start-up Research Fund of Southeast University(4031002412).
文摘Recent advancements in single-molecule biophysics have been driven by breakthroughs in advanced fluorescence microscopy techniques and the development of nextgeneration organic fluorophores.These cutting-edge fluorophores,coupled through tailored biolabeling strategies,offer single-molecule brightness,photostability,and phototunability(i.e.,photoswitchable,photoactivatable),contributing to enhancing spatial and temporal imaging resolution for studying biomolecular interactions and dynamics at single-event precision.This review examines the progress made over the past decade in the development of next-generation fluorophores,along with their site-specific labeling methods for proteins,nucleic acids,and biomolecular complexes.It also explores their applications in single-molecule fluorescencebased dynamic structural biology and super-resolution microscopy imaging.Furthermore,it examines ongoing efforts to address challenges associated with fluorophore photostability,photobleaching,and the integration of advanced photophysical and photochemical functionalities.The integration of state-of-the-art fluorophores with advanced labeling strategies aim to deliver complementary correlative data,holding promise for revolutionizing single-molecule biophysics by pushing the boundaries of temporal and spatial imaging resolution to unprecedented limits.
基金National Natural Science Foundation of China,Grant/Award Numbers:523731405217312951973092,52103157China Postdoctoral Science Foundation,Grant/Award Numbers:2022M711544,2023T160301。
文摘Creation of new fluorophores is important for understanding the structure-property relationship,by which the required optical properties are likely to be attained.Herein,through theory calculation,it is found that furan-modified thiadiazolo quinoxaline acting as an electron acceptor can endow donor-acceptor-donor(D-A-D)type second near-infrared(NIR-Ⅱ)fluorophores with longer emission wavelength than the other thiadiazolo quinoxaline-based acceptors containing pyridine,pyrrole,thiophene,and phenyl groups,respectively.On the basis of this theoretical prediction,a D-A-D type NIR-Ⅱ fluorophore with 6,7-di(furan-2-yl)-[1,2,5]thiadiazolo[3,4-g]quinoxaline(DFTQ)as the acceptor and dithieno[3,2-b:2′,3′-d]pyrrole(DTP)as the donor is designed and synthesized,and the aggregation-induced emission(AIE)function is further achieved by introducing the AIE units of tetraphenylethylene(TPE)and triphenylamine(TPA),respectively,totally forming three NIR-Ⅱ fluorophores DFTQ-DTP,DFTQ-DTPE,and DFTQ-DTPA.For biological applications,the fluorophores are encapsulated by amphiphilic DSPE-PEG2000 to generate water-dispersible nanoparticles(NPs).Almost the whole emission of each of the NPs falls into the NIR-Ⅱ spectral range,with part emission beyond 1300 nm.By using DFTQ-DTPA NPs as the contrast and photothermal therapy(PTT)agent,high-resolution in vivo fluorescence imaging is achieved in the greater than 1300 nm window,and their good performance in photoacoustic imaging and high tumor PTT efficacy in tumor-bearing mice are also demonstrated.Taken together,this work mainly provides a strong electron acceptor for constructing longemitting fluorophores,and by using the electron acceptor,a AIE fluorophore with desirable quantum yield(QY)and photothermal conversion efficienciy(PCE)is synthesized and demonstrated to be promising in fluorescence/photoacoustic imaging and PTT.
基金Research Center for Industries of the Future(RCIF),Westlake UniversityNational Natural Science Foundation of China„Grant/Award Numbers:22007048,22222410Natural Science Foundation of Jiangsu Basic Research Program„Grant/Award Number:BK20221324。
文摘Molecular rotor-based fluorophores(RBFs)activate fluorescence upon increase of micro-viscosity,thus bearing a broad application promise in many fields.However,it remains a challenge to control how fluorescence of RBFs responds to viscosity changes.Herein,we demonstrate that the formation and regulation of intramolecular hydrogen bonds in the excited state of RBFs could modulate their rotational barrier,leading to a rational control of how their fluorescence can be activated by micro-viscosity.Based on this strategy,a series of RBFs were developed based on 4-hydroxybenzylidene-imidazolinone(HBI)that span a wide range of viscosity sensitivity.Combined with the AggTag method that we previously reported,the varying viscosity sensitivity and emission spectra of these probes enabled a dualcolor imaging strategy that detects both protein oligomers and aggregates during the multistep aggregation process of proteins in live cells.In summary,our work indicates that installing intracellular excited state hydrogen bonds to RBFs allows for a rational control of rotational barrier,thus allow for a fine tune of their viscosity sensitivity.Beyond RBFs,we envision similar strategies can be applied to control the fluorogenic behavior of a large group of fluorophores whose emission is dependent on excited state rotational motion,including aggregation-induced emission fluorophores.
基金supported by the National Nature Science Foundation of China(Nos.62075079,62305127,61975200)the Natural Science Foundation of Jilin Province(20230508135RC)the Science and Technology Development Foundation of Changchun City(23GZZ15).
文摘The fluorescence imaging (FLI) in the second near-infrared window (NIR-II, 1000–1700nm) has attracted considerable attention in the past decade. In contrast to conventional NIR-I window excitation (808nm/980nm), FLI with NIR-II window excitation (1064nm/other wavelength beyond 1000nm) can afford deeper tissue penetration depth with high clarity due to the merits of suppressed photon scattering and diminished autofluorescence. In this review, we have summarized NIR-II window excitable/emissive organic/polymeric fluorophores recently developed. The characteristics of these fluorophores such as chemical structures and photophysical properties have also been critically discussed. Furthermore, the latest development of noninvasive in vivo FLI with NIR-II excitation was highlighted. The ideal imaging results emphasized the importance of NIR-II excitation of these fluorophores in enabling deep tissue penetration and high-resolution imaging. Finally, a perspective on the challenges and prospects of NIR-II excitable/emissive organic/polymeric fluorophores was also discussed. We expected this review will be served as a source of inspiration for researchers, stimulating the creation of novel NIR-II excitable fluorophores and fostering the development of bioimaging applications.
基金support from the National Natural Science Foundation of China (Nos. 62175201 and 52373142)the Natural Science Foundation of Jiangsu Province of China (No. BK20220404)+1 种基金the Fundamental Research Funds for the Central Universitiesthe open research fund of State Key Laboratory of Organic Electronics and Information Displays.
文摘Fluorophores emitting in the second near-infrared window (NIR-II, 900–1700nm) allow for high-resolution deep-tissue bioimaging owing to minimal tissue scattering. Although J-aggregation offers a promising approach to developing long-wavelength emitters, the scarcity of J-type backbones and reliable design principles limits their application in biological imaging. Here, we introduce a strategy for engineering high-brightness NIR-II J-aggregated fluorophores by incorporating electron-withdrawing substituents into a fused-ring backbone. These substituents modulate the electrostatic potential (ESP) distribution across the conjugated backbone, reducing both electrostatic repulsion and intermolecular distance, which promotes ordered J-aggregation. As a result, Y8 aggregate (Y8 nanoparticles) exhibits an outstanding fluorescence quantum yield of up to 12.9% and strong near-infrared absorption in aqueous solution for high-performance NIR-II fluorescence imaging in vivo. This work not only presents a novel J-type backbone but also advances the understanding of the structure–property relationship critical to designing NIR-II J-aggregates.
基金supported by National Key Research and Development Program of China(2019YFA0210500)National Natural Science Foundation of China(21977054,21877102 and 91953107)
文摘Fluorescence imaging is a useful tool in the field of biomedical applications.However,its imaging capacity is limited by the depth of tissue that can be penetrated when using visible light(400-700 nm)or the first near-infrared window(NIR-Ⅰ,700-900 nm).To overcome the problem,fluorescence imaging in the second near-infrared window(NIR-Ⅱ,1000-1700 nm)has been developed to reduce photon scattering,auto-absorption and tissue autofluorescence to achieve high spatiotemporal resolution and deep imaging penetration.The key to NIR-Ⅱimaging is obtaining and analyzing highly selective information from functional fluorophores that emit in the 1000-1700 nm range.With the rapid development of multidisciplinary research,various types of NIR-Ⅱfluorophores have been produced and used in non-invasive,real-time NIR-Ⅱbiomedical applications.This review summarizes some of the most prevalent NIR-Ⅱfluorophores and their synthesis,such as organic fluorophores(OFs),single-walled carbon nanotubes(SWCNTs),quantum dots(QDs),and rare-earth nanoparticles(RENPs).On this basis,we describe the applications of these fluorophores in biomedical fields,including bioimaging,biosensing,phototherapy and surgical navigation.Additionally,major challenges and prospects of NIR-Ⅱbiomedical application will be further explored.
基金financed by start-up funding provided by the University of Hamburg
文摘Peroxisome research has been revolutionized by proteome studies combined with in vivo subcellular targeting analyses. Yellow and cyan fluorescent protein(YFP and CFP) are the classical fluorophores of plant peroxisome research. In the new transient expression system of Arabidopsis seedlings co-cultivated with Agrobacterium we detected the YFP fusion of one candidate protein in peroxisomes, but only upon co-transformation with the peroxisome marker, CFP-PTS1. The data suggested that the YFP fusion was directed to peroxisomes due to its weak heterodimerization ability with CFP-PTS1,allowing piggy-back import into peroxisomes. Indeed, if co-expressed with monomeric Cerulean-PTS1(mCer-PTS1),the YFP fusion was no longer matrix localized. We systematically investigated the occurrence and extent of dimerization-based piggy-back import for different fluorophore combinations in five major transient plant expression systems. In Arabidopsis seedlings and tobacco leaves both untagged YFP and monomeric Venus were imported into peroxisomes if co-expressed with CFP-PTS1 but not with mCer-PTS1. By contrast, piggy-back import of cytosolic proteins was not observed in Arabidopsis and tobacco protoplasts or in onion epidermal cells for any fluorophore combination at any time point. Based on these important results we formulate new guidelines for fluorophore usage and experimental design to guarantee reliable identification of novel plant peroxisomal proteins.
基金The work was supported by the National Natural Science Foundation of China(NNSFC)(61525402,61775095)Natural Science Foundation of Jiangsu Province(BK20200092)+2 种基金Jiangsu Province Policy Guidance Plan(BZ2019014)Six talent peak innovation team in Jiangsu Province(TD-SWYY-009)“Taishan scholars”construction special fund of Shandong Province.
文摘Phototheranostics integrates deep-tissue imaging with phototherapy(containing photothermal therapy and photodynamic therapy),holding great promise in early diagnosis and precision treatment of cancers.Recently,second near-infrared(NIR-II)fluorescence imaging exhibits the merits of high accuracy and specificity,as well as real-time detection.Among the NIR-II fluorophores,organic small molecular fluorophores have shown superior properties in the biocompatibility,variable structure,and tunable emission wavelength than the inorganic NIR-II materials.What’s more,some small molecular fluorophores also display excellent cytotoxicity when illuminated with the NIR laser.This review summarizes the progress of small molecular NIR-II fluorophores with different central cores for cancer phototheranostics in the past few years,focusing on the molecular structures and phototheranostic performances.Furthermore,challenges and prospects of future development toward clinical translation are discussed.
基金supported by the National Natural Science Foundation of China (21605008, 21735001, 21575018, 21505006)the Hunan Provincial Natural Science Foundation (2016JJ3001)
文摘Because of their important roles in cellular functions, life activities, drug screening, and disease treatment, the development of efficient methods for monitoring protein-ligand interaction is essential. In this study, inspired by our previous studies on DNA conformation-selective fluorescent indicators, we developed a new sensing platform for monitoring protein-ligand interaction and detecting protein activity based on binding-mediated DNA protection and the dsDNA-lighted fluorophore, ethyl-4-[3,6-bis(1-methyl-4-vinylpyridium iodine)-9 H-carbazol-9-yl)] butanoate(EBCB). The ligand was purposefully linked to the 3?-terminal of a hairpin DNA probe to selectively bind with the target protein and protect the DNA from cleavage by exonuclease III. By virtue of EBCB's outstanding capacity to discriminate DNA conformation, the protein-ligand interaction could be effectively monitored through a fluorescence change in EBCB. A high fluorescence signal was detected when the hairpin DNA was protected in the presence of the target protein, whereas a much lower signal was observed in the presence of nontarget proteins.Our results demonstrated that the proposed strategy had high potential, such as high selectivity and relatively high sensitivity, for monitoring protein-ligand interaction and detecting protein activity. We believe these results will pave the way for applying dsDNA-lighted fluorophore EBCB as an effective signal transducer for DNA conformation transformation-mediated biochemical sensing.
基金supported by the National Science Foundation(CHE-2203609).
文摘Here we report the use of a Langmuir isotherm model to analyze and better understand the dynamic adsorption and desorption behavior of single fluorophore molecules at the surface of a hydrogen nanobubble supported on an indium tin oxide(ITO)electrode.Three rhodamine dyes,rhodamine 110(R110,positively charged),rhodamine 6G(R6G,positively charged),and sulforhodamine G(SRG,negatively charged)were chosen for this study.The use of the Langmuir isotherm model allows us to determine the equilibrium constant and the rate constants for the adsorption and desorption processes.Of the three fluorophores used in this study,SRG was found to have the greatest equilibrium constant.No significant potential dependence was observed on the adsorption characteristics,which suggests the nanobubble size,geometry,and surface properties are relatively constant within the range of potentials used in this study.Our results suggest that the use of the Langmuir isotherm model is a valid and useful means for probing and better understanding the unique adsorption behavior of fluorophores at surface-supported nanobubbles.
