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
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
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
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
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
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
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
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
Multidimensional single-molecule localization microscopy(mSMLM)represents a paradigm shift in the realm of super-resolution microscopy techniques.It affords the simultaneous detection of singlemolecule spatial locatio...Multidimensional single-molecule localization microscopy(mSMLM)represents a paradigm shift in the realm of super-resolution microscopy techniques.It affords the simultaneous detection of singlemolecule spatial locations at the nanoscale and functional information by interrogating the emission properties of switchable fluorophores.The latter is finely tuned to report its local environment through carefully manipulated laser illumination and single-molecule detection strategies.This Perspective highlights recent strides in mSMLM with a focus on fluorophore designs and their integration into mSMLM imaging systems.Particular interests are the accomplishments in simultaneous multiplexed super-resolution imaging,nanoscale polarity and hydrophobicity mapping,and single-molecule orientational imaging.Challenges and prospects in mSMLM are also discussed,which include the development of more vibrant and functional fluorescent probes,the optimization of optical implementation to judiciously utilize the photon budget,and the advancement of imaging analysis and machine learning techniques.展开更多
Organic polymethine fluorophores with emission in the NIR-II window(1000−1700 nm)are receiving enormous attention in biomolecular medicine and bioimaging,attributed to the high absorption coefficients,bright NIR-II em...Organic polymethine fluorophores with emission in the NIR-II window(1000−1700 nm)are receiving enormous attention in biomolecular medicine and bioimaging,attributed to the high absorption coefficients,bright NIR-II emission,excellent biocompatibility,and molecule adjustability.Recently,researchers have devoted significant effort to designing and improving NIR-II polymethine fluorophores and making notable progress in the NIR-II fluorescence imaging performance.This review summarizes recent developments in the molecular engineering design mentality of polymethine fluorophores and probes and highlights their extensive bioimaging and biosensing applications.Furthermore,we elucidate the potential challenges and perspectives of these NIR-II polymethine dyes in chemical and biomedicine imaging,which may stimulate the further development of high-performance NIR-II polymethine dye contrast agents for their future clinical applications.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
Biothiols,including cysteine(Cys),homocysteine(Hey),and glutathione(GSH) play important roles in physiological processes,and the detection of thiol using fluorescent probes has attracted attention due to their high se...Biothiols,including cysteine(Cys),homocysteine(Hey),and glutathione(GSH) play important roles in physiological processes,and the detection of thiol using fluorescent probes has attracted attention due to their high sensitivity and selectively and invasive on-time imaging.However,the similar structures and reactivity of these biothiols present great challenges for selective detection.This review focused on the the "aromatic nucleophilic substitution-rearrangement(SNAr-rearrangement) mechanism",which provided a powerful tool to design fluorescent probes for the discrimination between biothiols.We classify the fluorescent probes according to types of fluorophores,such as difluoroboron dipyrromethene(BODIPY),nitrobenzoxadiazole(NBD),cyanine,pyronin,naphthalimide,coumarin,and so on.We hope this review will inspire exploration of new fluorescent probes for biothiols and other relevant analytes.展开更多
Two-photon imaging has attracted increasing attention owing to its deep tissue imaging capabilities.Therefore,many fluorophores have been developed to satisfy its requirements.However,long-wavelength emission fluoroph...Two-photon imaging has attracted increasing attention owing to its deep tissue imaging capabilities.Therefore,many fluorophores have been developed to satisfy its requirements.However,long-wavelength emission fluorophores with an optically tunable group are rarely developed.In this study,two longwavelength emission fluorophores with an optically tunable amino group were successfully developed by introducing strong electron acceptor and large conjugated group to the TPQL dye.TPCO_(2)displayed a bright red emission(λem=638 nm,Φ=0.15)together with high two-photon action cross section and good water solubility,which enabled higher signal-to-background ratios and deep tissue imaging.The proof-of-concept probe(TPCO-NO_(2))was successfully applied to the high signal-to-background ratio imaging of nitroreductase in liver fibrosis,further realizing diagnosis of the degree of hypoxia during liver fibrosis.展开更多
Objectives: Fluorescence spectroscopy which can be used for optical tissue diagnosis of tumor pathology?deserves special interest. The purpose of the work was to study blood plasma and tumor tissue of men with differe...Objectives: Fluorescence spectroscopy which can be used for optical tissue diagnosis of tumor pathology?deserves special interest. The purpose of the work was to study blood plasma and tumor tissue of men with different forms of prostate tumors by using laser induced fluorescence. Blood plasma and tumor tissue of the patients with benign hyperplasia of the prostate (BHP), BHP with inflammation, BHP with high grade PIN (BHP with HGPIN) and adenocarcinoma of prostate (CaP) have been studied. Results: In case of blood plasma fluorescence,?intensity of the plasma proteins corresponding peak (340 - 360 nm) was increasing in the following manner: control group → BHP → BHP with HGPIN → CaP. The intensity of the nicotinamide coenzymes correspond peak (440 - 460 nm) was increased in case of BHP with HGPIN and CaP patients, but decreased in case of BHP, compared to control. In case of tumor tissue, the changes of the collagen peak (390 - 400 nm) intensity have been revealed in all cases of prostate tumor tissues. These alterations point to altered collagen biosynthesis levels in different tumor tissues, that reflects the structural changes and characteristics of malignant transformation. Also the changes of the nicotinamide coenzymes peak (440 - 460 nm) intensity in all spectra of tumor tissues were observed. The highest intensity of the peak was observed in the spectra of BHP with HGPIN and in prostate cancer tissue. Conclusions: Alterations of the coenzymes peak intensities perfectly reflect and are in accordance with the specific energy metabolism of prostate epithelial cells. Normalization of fluorescent spectra from different forms of prostate tumor tissues has shown that, each form has typical spectral shape and ratio of fluorescence peaks intensities.展开更多
Simple structural compounds 1 to 3 were synthesized.The presence of Cu^（2＋） resulted in the fluorescence and absorption spectra change of 1 and 2,which indicated that 1 and 2 showed a highly selective response to ...Simple structural compounds 1 to 3 were synthesized.The presence of Cu^（2＋） resulted in the fluorescence and absorption spectra change of 1 and 2,which indicated that 1 and 2 showed a highly selective response to Cu^（2＋） over other metal ions.However,3 showed no selectivity for metal ions,which means that the compound could bind with several metal ions,such as,Ni^（2＋）,Zn^（2＋）,Cd^（2＋）.Hg^（2＋）, Pb^（2＋）,Fe^（3＋）,Mg^（2＋）,Ca^（2＋）,and Co^（2＋）,except Cu^（2＋） and Ag~＋.The different spectral responses were attributed to the difference in binding sites for 1 and 3.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
The harm of pathogenic bacteria to humans has promoted extensive research on physiological processes of pathogens,such as the mechanism of bacterial infection,antibiotic mode of action,and bacterial antimicrobial resi...The harm of pathogenic bacteria to humans has promoted extensive research on physiological processes of pathogens,such as the mechanism of bacterial infection,antibiotic mode of action,and bacterial antimicrobial resistance.Most of these processes can be better investigated by timely tracking of fluorophore-derived antibiotics in living cells.In this paper,we will review the recent development of fluorescent antibiotics featuring the conjugation with various fluorophores,and focus on their applications in fluorescent imaging and real-time detection for various physiological processes of bacteria in vivo.展开更多
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 the National Institutes of Health grants R21GM141675 and R01GM143397the National Science Foundation grant CHM-1954430 and CHM-2246548the National Research Foundation of Korea grant No.NRF-2022R1C1C1002850.
文摘Multidimensional single-molecule localization microscopy(mSMLM)represents a paradigm shift in the realm of super-resolution microscopy techniques.It affords the simultaneous detection of singlemolecule spatial locations at the nanoscale and functional information by interrogating the emission properties of switchable fluorophores.The latter is finely tuned to report its local environment through carefully manipulated laser illumination and single-molecule detection strategies.This Perspective highlights recent strides in mSMLM with a focus on fluorophore designs and their integration into mSMLM imaging systems.Particular interests are the accomplishments in simultaneous multiplexed super-resolution imaging,nanoscale polarity and hydrophobicity mapping,and single-molecule orientational imaging.Challenges and prospects in mSMLM are also discussed,which include the development of more vibrant and functional fluorescent probes,the optimization of optical implementation to judiciously utilize the photon budget,and the advancement of imaging analysis and machine learning techniques.
基金supported by National Natural Science Foundation of China(22234003,22004033)Special Funds for the Construction of Innovative Provinces in Hunan Province(2019RS1031).
文摘Organic polymethine fluorophores with emission in the NIR-II window(1000−1700 nm)are receiving enormous attention in biomolecular medicine and bioimaging,attributed to the high absorption coefficients,bright NIR-II emission,excellent biocompatibility,and molecule adjustability.Recently,researchers have devoted significant effort to designing and improving NIR-II polymethine fluorophores and making notable progress in the NIR-II fluorescence imaging performance.This review summarizes recent developments in the molecular engineering design mentality of polymethine fluorophores and probes and highlights their extensive bioimaging and biosensing applications.Furthermore,we elucidate the potential challenges and perspectives of these NIR-II polymethine dyes in chemical and biomedicine imaging,which may stimulate the further development of high-performance NIR-II polymethine dye contrast agents for their future clinical applications.
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.
基金financially supported by the National Natural Science Foundation of China (No. 21525206)
文摘Biothiols,including cysteine(Cys),homocysteine(Hey),and glutathione(GSH) play important roles in physiological processes,and the detection of thiol using fluorescent probes has attracted attention due to their high sensitivity and selectively and invasive on-time imaging.However,the similar structures and reactivity of these biothiols present great challenges for selective detection.This review focused on the the "aromatic nucleophilic substitution-rearrangement(SNAr-rearrangement) mechanism",which provided a powerful tool to design fluorescent probes for the discrimination between biothiols.We classify the fluorescent probes according to types of fluorophores,such as difluoroboron dipyrromethene(BODIPY),nitrobenzoxadiazole(NBD),cyanine,pyronin,naphthalimide,coumarin,and so on.We hope this review will inspire exploration of new fluorescent probes for biothiols and other relevant analytes.
基金supported by the National Natural Science Foundation of China(Nos.22074036,22004033,21877029)Special Funds for the Construction of Innovative Provinces in Hunan Province(No.2019RS1031)。
文摘Two-photon imaging has attracted increasing attention owing to its deep tissue imaging capabilities.Therefore,many fluorophores have been developed to satisfy its requirements.However,long-wavelength emission fluorophores with an optically tunable group are rarely developed.In this study,two longwavelength emission fluorophores with an optically tunable amino group were successfully developed by introducing strong electron acceptor and large conjugated group to the TPQL dye.TPCO_(2)displayed a bright red emission(λem=638 nm,Φ=0.15)together with high two-photon action cross section and good water solubility,which enabled higher signal-to-background ratios and deep tissue imaging.The proof-of-concept probe(TPCO-NO_(2))was successfully applied to the high signal-to-background ratio imaging of nitroreductase in liver fibrosis,further realizing diagnosis of the degree of hypoxia during liver fibrosis.
文摘Objectives: Fluorescence spectroscopy which can be used for optical tissue diagnosis of tumor pathology?deserves special interest. The purpose of the work was to study blood plasma and tumor tissue of men with different forms of prostate tumors by using laser induced fluorescence. Blood plasma and tumor tissue of the patients with benign hyperplasia of the prostate (BHP), BHP with inflammation, BHP with high grade PIN (BHP with HGPIN) and adenocarcinoma of prostate (CaP) have been studied. Results: In case of blood plasma fluorescence,?intensity of the plasma proteins corresponding peak (340 - 360 nm) was increasing in the following manner: control group → BHP → BHP with HGPIN → CaP. The intensity of the nicotinamide coenzymes correspond peak (440 - 460 nm) was increased in case of BHP with HGPIN and CaP patients, but decreased in case of BHP, compared to control. In case of tumor tissue, the changes of the collagen peak (390 - 400 nm) intensity have been revealed in all cases of prostate tumor tissues. These alterations point to altered collagen biosynthesis levels in different tumor tissues, that reflects the structural changes and characteristics of malignant transformation. Also the changes of the nicotinamide coenzymes peak (440 - 460 nm) intensity in all spectra of tumor tissues were observed. The highest intensity of the peak was observed in the spectra of BHP with HGPIN and in prostate cancer tissue. Conclusions: Alterations of the coenzymes peak intensities perfectly reflect and are in accordance with the specific energy metabolism of prostate epithelial cells. Normalization of fluorescent spectra from different forms of prostate tumor tissues has shown that, each form has typical spectral shape and ratio of fluorescence peaks intensities.
基金supported by Natural Science Foundation of China(No20965006)
文摘Simple structural compounds 1 to 3 were synthesized.The presence of Cu^（2＋） resulted in the fluorescence and absorption spectra change of 1 and 2,which indicated that 1 and 2 showed a highly selective response to Cu^（2＋） over other metal ions.However,3 showed no selectivity for metal ions,which means that the compound could bind with several metal ions,such as,Ni^（2＋）,Zn^（2＋）,Cd^（2＋）.Hg^（2＋）, Pb^（2＋）,Fe^（3＋）,Mg^（2＋）,Ca^（2＋）,and Co^（2＋）,except Cu^（2＋） and Ag~＋.The different spectral responses were attributed to the difference in binding sites for 1 and 3.
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.
基金We are grateful for the financial support from the National Natural Science Foundation of China(21878286,21908216,21576043)Dalian Institute of Chemical Physics(DICPI201938,DICP I202006).
文摘The harm of pathogenic bacteria to humans has promoted extensive research on physiological processes of pathogens,such as the mechanism of bacterial infection,antibiotic mode of action,and bacterial antimicrobial resistance.Most of these processes can be better investigated by timely tracking of fluorophore-derived antibiotics in living cells.In this paper,we will review the recent development of fluorescent antibiotics featuring the conjugation with various fluorophores,and focus on their applications in fluorescent imaging and real-time detection for various physiological processes of bacteria in vivo.
