The aggressive nature and high mortality rate of lung cancer underscore the imperative need for early diagnosis of the disease.Thus,aminopeptidase N(APN),a potential biomarker for lung cancer,should be thoroughly inve...The aggressive nature and high mortality rate of lung cancer underscore the imperative need for early diagnosis of the disease.Thus,aminopeptidase N(APN),a potential biomarker for lung cancer,should be thoroughly investigated in this context.This report describes the development of HA-apn,a novel near-infrared fluorescent probe,specifically engineered for the sensitive detection of endogenous APN.Characterized by its high selectivity,straightforward molecular architecture,and suitable optical properties,including a long-wavelength emission at 835 nm and a large Stokes shift of 285 nm,HA-apn had high efficacy in identifying overexpressed APN in tumor cells,which shows its potential in pinpointing malignancies.To further validate its applicability and effectiveness in facilitating the direct and enhanced visualization of pulmonary alterations,an in situ lung cancer mouse model was employed.Notably,HAapn was applied for in vivo imaging of APN activity in the lung cancer mouse model receiving the probe through aerosol inhalation,and rapid and precise diagnostic results were achieved within 30min postadministration.Overall,HA-apn can be applied as an effective,non-intrusive tool for the rapid and accurate detection of pulmonary conditions.展开更多
Red fluorescent proteins with large Stokes shift(LSS-RFPs)are advantageous for multicolor imaging applications that allow simultaneous visualizations of multiple biological events.But it is difficult to develop LSS-RF...Red fluorescent proteins with large Stokes shift(LSS-RFPs)are advantageous for multicolor imaging applications that allow simultaneous visualizations of multiple biological events.But it is difficult to develop LSS-RFPs by extending the emission wavelength of RFPs to far-red region.Here,we employed Forster resonance energy transfer(FRET)strategy to engineer the far-red fluorescent proteins with large Stokes shift.LSS-m Apple and LSS-mCherry were constructed by fusing HaloTag to m Apple and mCherry,allowing the fluorophore TMSi R to be connected to these RFPs.FRET between RFPs and TMSi R enabled them to apply the excitation of donor RFPs to emit far-red fluorescence of acceptor TMSi R.The Stokes shifts of LSS-m Apple and LSS-mCherry were 97 nm and 75 nm,respectively.The high FRET efficiency of LSS-mCherry(E_(FRET)=83.7%)can greatly reduce the fluorescence from the donor channel,which did not affect co-imaging with mCherry.In addition,LSS-mCherry also showed excellent photostability(t_(1/2)=449.3 s),enabling stable confocal fluorescence imaging for 15 min under continuous strong excitation.Furthermore,LSS-mCherry was applied for fluorescence labeling and imaging of the nucleus,mitochondria,lysosomes,and endoplasmic reticulum in living cells.Finally,we applied LSS-mCherry to perform multi-color bioimaging of 2–4 channels,and there was no obvious crosstalk between these channels.展开更多
As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an inno...As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an innovative long-wavelength emission fluorescent probe TCF-CHT was designed and synthesized for the high specificity detection of CHT,which utilized TCF-OH and a mimetic peptide substrate 4-bromobutyryl as chromogenic group and recognition group,respectively.TCF-CHT exhibited excellent selectivity and eye-catching sensitivity(8.91 ng/m L)towards CHT,“off-on”long-wavelength emission at 670 nm and large Stokes shift(140 nm).Furthermore,the successful fulfillment and perfect performance in imaging endogenous CHT in complex organisms(P815 cells,HepG2 cells,zebrafish and tumor-bearing mice)verified its potential as a powerful tool for the recognition of CHT in complicated biological environments.展开更多
The Stokes shift response function, which is related to the time dependent solvation energy, is calculated with the dielectric response function and a novel expression of nonequilibrium solvation energy. In the deriva...The Stokes shift response function, which is related to the time dependent solvation energy, is calculated with the dielectric response function and a novel expression of nonequilibrium solvation energy. In the derivation, relationship between the polarization and the dielectric response function is used. With the dipole-in-a-sphere model applied to the system coumarin 343 and water as the solvent, encouraging agreement with the experimental data from Jimenez et al. is obtained [Nature 369, 471 （1994）].展开更多
Developing the novel fluorescent dyes with a larger Stokes shift is still a challenge in the research of fluorescence probes. In this work, a naphthalimide-modified near-infrared cyanine dye with an emission at 785 nm...Developing the novel fluorescent dyes with a larger Stokes shift is still a challenge in the research of fluorescence probes. In this work, a naphthalimide-modified near-infrared cyanine dye with an emission at 785 nm has been synthesized for lysosome-targeting imaging. This fluorescent dye showed a large Stokes shift（up to 165 nm） and favorable lysosome-targeting property, which facilitated it to be a potential candidate for studying of lysosomal functions. The result also indicated that the probe is a promising contrast agent for in vivo imaging in mouse models.展开更多
Fluorescent probes have been widely employed in biological imaging and sensing.However,it is always a challenge to design probes with high sensitivity.In this work,based on rhodamine skeleton,we developed a general st...Fluorescent probes have been widely employed in biological imaging and sensing.However,it is always a challenge to design probes with high sensitivity.In this work,based on rhodamine skeleton,we developed a general strategy to construct sensitivity-enhanced fluorescent probe with the help of theoretical calculation for the first time.As a proof of concept,we synthesized a series of HOCl probes.Experiment results showed that with the C-9 of pyronin moiety of rhodamine stabilized by an electron donor group,probe DQF-S exhibited an importantly enhanced sensitivity(LOD:0.2 nmol/L)towards HOCl together with fast response time(<10 s).Moreover,due to the breaking symmetrical electron distribution by another electron donor group,the novel rhodamine probe DQF-S displayed a far red to near-infrared emission(>650 nm)and large Stokes shift.Bioimaging studies indicated that DQF-S can not only effectively detect basal HOCl in various types of cells,but also be successfully applied to image tumor tissue in vivo.These results demonstrate the potential of our design as a useful strategy to develop excellent fluorescent probes for bioimaging.展开更多
Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been report...Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been reported,the development of H2O2 ratiometric fluorescent probe with large Stokes shift remains rather limited.Such probes have shown distinct advantages,such as minimized interference from environment and improved signal-to noise ratio.In this work,we reported a new pyrene-based compound Py-VPB as H2O2 fluorescent probe in vitro.The probe demonstrated ratiometric detection behavior,large Stokes shift and large emission shift.In addition,the probe showed high sensitivity and selectivity towards H2O2 in vitro.Based on these excellent properties,we successfully applied Py-VPB to the visualization of exogenous and endogenous H2O2 in living cells.Cell imaging study also showed that our probe was localized in the mitochondria.We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H2O2 in living systems.展开更多
Rhodamine dyes have been widely employed in biological imaging and sensing. However, it is always a challenge to design rhodamine derivatives with huge Stokes shift to address the draconian requirements of single-exci...Rhodamine dyes have been widely employed in biological imaging and sensing. However, it is always a challenge to design rhodamine derivatives with huge Stokes shift to address the draconian requirements of single-excitation multicolor imaging. In this work, we described a generally strategy to enhance the Stokes shift of rhodamine dyes by completely breaking their electronic symmetry. As a result, the Stokes shift of novel rhodamine dye DQF-RB-Cl is up to 205 nm in PBS, which is the largest in all the reported rhodamine derivatives. In addition, we successfully realized the single excitation trichromatic imaging of mitochondria, lysosomes and cell membranes by combining DQF-RB-Cl with commercial lysosomal targeting probe Lyso-Tracker Green and membrane targeting dye Dil. This is the organic synthetic dyes for SLE-trichromatic imaging in cells for the first time. These results demonstrate the potential of our design as a useful strategy to develop huge Stokes shift fluorophore for bioimaging.展开更多
Chrornophore structures inspired by natural green fluorescent protein （GFP） play an im- portant role in the field of bio-irnaging. In this work, photochemical properties of a new class of GFP-like chromophores are i...Chrornophore structures inspired by natural green fluorescent protein （GFP） play an im- portant role in the field of bio-irnaging. In this work, photochemical properties of a new class of GFP-like chromophores are investigated using computational approaches. Thermo- dynamically stable isomers are identified in vacuum and in solvent. Spectral Stokes shifts are computed and compared to experiments. An inverted solvatochromic shift between absorption and emission emerging in this new class of GFP-like chromophores is observed, and attributed to the stabilized charge transfer and inhibited rotational structural reorganization in solvent.展开更多
Herein,the 2,4-dinitrophenyl functional group acting as the thiophenol reactive site was introduced into a carbazole-chalcone fluorophore to synthesize probe-CCF2,which could result in a remarkable increase in fluores...Herein,the 2,4-dinitrophenyl functional group acting as the thiophenol reactive site was introduced into a carbazole-chalcone fluorophore to synthesize probe-CCF2,which could result in a remarkable increase in fluorescence when reacting with thiophenols.The selectivity and accuracy of probe-CCF2 were investigated with thiophenols,hydrosulphide salt,aliphatic thiols,glutathione,cysteine,anions and metal cations.Probe-CCF2 exhibited a detection limit of 37 nmol/L(R^(2)=0.9951),a remarkable Stokes shift of approximately 130 nm,and a brief response time of 9 min with a remarkable increase in fluorescence of 90-fold.Probe-CCF2 was applied for thiophenol detection in water samples and imaging in living cells successfully,with high sensitivity and excellent selectivity.展开更多
A simple, mild and efficient one-pot approach for the construction of 2-aryl-3-nitro-2,9-dihydrothiopyrano- [2,3-b]indole derivatives has been realized in CH2C12 medium at ambient temperature via three-component tande...A simple, mild and efficient one-pot approach for the construction of 2-aryl-3-nitro-2,9-dihydrothiopyrano- [2,3-b]indole derivatives has been realized in CH2C12 medium at ambient temperature via three-component tandem reaction of N-protected-2-chloro-3-formylindoles, sodium hydrosulfide and β-substituted nitroolefins/δ-substituted nitrodienes using DABCO （10 mol%） as an organocatalyst, followed by dehydration in the presence of activated molecular sieves （4 A）. The significant advantages of this protocol are simple operation, shorter reaction time, high atom economy, good to high yields （73%-89%） and wider substrate scope. In addition, all the synthesized com- pounds have shown the large positive Stokes shift values （5632-6081 cm ^-1）.展开更多
During the last decade,a great variety of ligand protected gold nanoclusters(AuNCs)have been synthesized,and their broad applications have been intensively reported.Although the spectroscopic properties of AuNCs have ...During the last decade,a great variety of ligand protected gold nanoclusters(AuNCs)have been synthesized,and their broad applications have been intensively reported.Although the spectroscopic properties of AuNCs have been comprehensively explored,the mechanism of the significant Stokes shift(>200 nm)and the specific role played by surface ligands have not been clearly explained yet.In this study,a series of fluorescent AuNCs with huge Stokes shift(up to 530 nm)were successfully prepared by employing the rationally designed tri-peptides as the protecting ligands,and their spectroscopic properties were systematically investigated.The detailed measurements on the example product,YCY-AuNCs(Tyr-Cys-Tyr liganded AuNCs),showed that the energy absorbed by the tyrosine(~250 nm)can be effectively transferred through the ligand-mediated two-step Förster resonance energy transfer(FRET)process and released as fluorescence emission in the near-infrared fluorescence(NIR)range(~780 nm),which resulted in the significant apparent Stokes shift.The YCY ligands play a critical role by offering the tyrosine groups(donor of the first FRET pair),generating the dityrosine-like structure on the AuNCs surface(acceptor of the first FRET pair and donor of the second FRET pair),and protecting the cores(acceptor of the second acceptor).The additional ligand exchange experiments and the investigation on the other AuNCs further demonstrated that the sufficient high density of the aromatic groups is also essential to mediate the two-step FRET and achieve the remarkable Stokes shift.We believe that the aromatic ligand-mediated FRET mechanism not only offers a new theoretical explanation for the huge Stokes shift exhibited in AuNCs,but also provides a general strategy for the construction of new materials with large Stokes shift.展开更多
Four benzocoumarin-based two-photon fluorescent probes(BH1-BH4)are proposed for ra-tiometric detection of hypochlorous acid(HClO)and their two-photon sensing perfor-mance are evaluated by means of time-dependent densi...Four benzocoumarin-based two-photon fluorescent probes(BH1-BH4)are proposed for ra-tiometric detection of hypochlorous acid(HClO)and their two-photon sensing perfor-mance are evaluated by means of time-dependent density func-tional theory and quadratic re-sponse theory.The effects of benzene-fused position on Stokes shift,fluorescence quantum yield and two-photon absorption are discussed comprehensively.The results show that fusing a benzene ring in coumarin can enhance Stokes shift efficiently.The benzene-fused position has important effects on these photophysical properties.The benzo[g]coumarins(BH1)and benzo[f]coumarins(BH2)derivatives have larger Stokes shifts in comparison with benzo[h]coumarins(BH3)and dihydrophenazine(BH4)derivatives.The two-photon absorp-tion of benzo[f]coumarins(BH2)derivative is much smaller than those of other benzo-coumarins derivatives.The large Stokes shift and increased two-photon action cross section can be achieved simultaneously in the dihydrophenazine(BH4)derivative.Therefore,the de-signed BH4 is expected to have superior performance for the ratiometric detection of HClO.To explore the reasons behind these effects,the intramolecular charge transfer degrees are il-lustrated quantitatively by plotting the hole-electron isosurface map,and the relation be-tween charge transfer and Stokes shift is revealed.A two-state model analysis is employed to understand two-photon absorption ability.Moreover,the fluorescence near-quenching mecha-nism of the product molecules B1 and B3 is explained by analyzing reorganization energy and Huang-Rhys factor,as well as related normal mode.Our research could contribute to the effi-cient design of ratiometric two-photon fluorescent probes with large Stokes shift and signifi-cant two-photon action cross section.展开更多
Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atheroscleros...Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atherosclerosis.The aberrant accumulation of lipid droplets(LDs)in hepatocytes is a prominent signature of NAFLD.However,conventional techniques lack the capability to effectively monitor the dynamic changes in LD levels during NAFLD with living organisms.Hence,it is imperative to develop LD-specific long-wavelength fluorescent probes with high imaging contrast for the in-situ diagnosis of NAFLD.In this study,we synthesized a new LD-selective long-wavelength fluorescent probe,denoted as LD-1,based on the twisted intramolecular charge transfer(TICT)mechanism.The probe exhibits a large Stokes shift and intensive fluorescence emission in nonpolar and viscous solutions.By self-assembling LD-1 with bovine serum albumin(BSA),a biocompatible,long-wavelength fluorescent probe hybrid,LD-1@BSA,was formed,allowing for LDs to be selectively imaged in hepatocytes.Moreover,LD-1@BSA successfully discriminates NAFLD cells before and after drug treatment,and achieves non-invasive and real-time monitoring of LD accumulation in a mouse model of NAFLD.展开更多
An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzedα-arylation and BF2complexation.The rapid structure-activity relationship(SAR)stud...An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzedα-arylation and BF2complexation.The rapid structure-activity relationship(SAR)studies indicated that unsymmetrical N,O-chelated BF2complexes were highly fluorescent in solid state,and exhibited large Stokes shifts,excellent photostability,along with insensitivity to p H.Theα-aryl group could not only modulate the electronic effect but also inhibit the intermolecularπ-πstacking to promote the aggregation-induced emission(AIE)effect.DFT calculations and experiments identified that the intramolecular charge transfer properties of these N,O-chelates could be switched by the modification of substituents,resulting tunable fluorescence wavelengths.Furthermore,post-complexation modification was accomplished,including Suzuki-Miyaura cross-coupling,Buchwald-Hartwig amination,oxidative cleavage,along with a unique triple substitution reaction involving propargyl Grignard reagents.The exemplificative application of dimethylamine substituted boron complex as a reversible acidic vapor sensor was also demonstrated.展开更多
Sulfydryl-contained(-SH)substances including hydrogen sulfide(H_(2)S),cysteine(Cys),homocysteine(Hcy)and glutathione(GSH)play crucial roles in living systems,and their variations are closely associated with various di...Sulfydryl-contained(-SH)substances including hydrogen sulfide(H_(2)S),cysteine(Cys),homocysteine(Hcy)and glutathione(GSH)play crucial roles in living systems,and their variations are closely associated with various diseases.Herein,we developed a near-infrared intramolecular charge transfer(ICT)based fluorescent probe Y-NBD,achieving detection of Cys/Hcy and H_(2)S with different fluorescent signals(green-red for Cys/Hcy,red for H_(2)S),large Stokes shifts(∼100/105nm or 191 nm)and high signal-background-ratio,but not responding to GSH.Y-NBD was successfully applied to image exogenous/endogenous Cys/Hcy and H_(2)S in various living cancer cells(HeLa,A549,and HepG2)and in zebrafish.It not only visualized the transformation pathway of several thiols in HepG2 cells but also verified that the intestine is the main site for the activation and metabolism of Y-NBD in zebrafish,as well as realized to evaluate the degree of drug-induced liver injury.This work provides a promising tool for imaging Cys/Hcy and H_(2)S in living systems and shows great potency in evaluating drug-induced liver injury and its treatment.展开更多
Thiophenol(PhSH)is an important raw material for organic synthesis,while its high toxicity to organisms makes it an environmental pollutant.Therefore,it is crucial to accurately detect PhSH and explore its metabolic p...Thiophenol(PhSH)is an important raw material for organic synthesis,while its high toxicity to organisms makes it an environmental pollutant.Therefore,it is crucial to accurately detect PhSH and explore its metabolic process in the living system.Herein,a near-infrared(NIR)fluorescent probe TEM-FB was developed for sensing PhSH with a turn-on fluorescent signal at 719nm and a large Stokes shift(198 nm)based on generating the intramolecular charge transfer(ICT)process.TEM-FB shows high specificity and significant sensitivity towards PhSH(detection limit:10 nmol/L)via the aromatic nucleophilic substitution mechanism.Furthermore,it was successfully applied to image PhSH in multiple cell lines and in zebrafish.Notably,we revealed the oxidative stress process caused by PhSH and demonstrated that the hydrogen peroxide(H_(2)O_(2))in cells would alleviate the poisonousness from exogenous PhSH for the first time.This work provides a promising bioimaging tool for monitoring PhSH in living systems and visualizing the process of oxidative stress induced by PhSH.展开更多
Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of ...Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.展开更多
Two novel thieno-[3,4-b]-pyrazine-based molecules, TP-E and TP-O, were designed and synthesized for potential application as red fluorescent emitters. The bulky tetraphenylethylene groups were attached at the peripher...Two novel thieno-[3,4-b]-pyrazine-based molecules, TP-E and TP-O, were designed and synthesized for potential application as red fluorescent emitters. The bulky tetraphenylethylene groups were attached at the periphery of the thieno-[3,4-b]-pyrazine core to form the non-planar molecules, as efficient solid- state emitting materials. The peripheral groups were grafted to the emissive core through either a conjugated acetylene bond, or a non-conjugated ether bond. These molecules exhibit strnng red fluorescence in both dilute solutions and in thin films with large Stokes shifts of over 100 nm. The cyclic voltammetry measurements showed the reversible oxidation and reduction behavior for both compounds. All these properties indicate the two compounds are possible functional materials for use in ontoelectronic devices.展开更多
This letter presents excited state intramolecular proton transfer (ESIPT) of new conjugated derivatives containing hydroxy and imino groups. ESIPT occurrence in one photon process is confirmed by well-separated emissi...This letter presents excited state intramolecular proton transfer (ESIPT) of new conjugated derivatives containing hydroxy and imino groups. ESIPT occurrence in one photon process is confirmed by well-separated emission band for the derivatives. Two- photon absorption (TPA) induced ESIPT emission has been determined by Ti:sapphire femtosecond laser tuning from 700 nrn to 800 nm at the internals of 20 nm.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22004046 and 22074052)the Science and Technology Developing Foundation of Jilin Province of China(Nos.20240404044ZP,20230101033JC and 20220505015ZP).
文摘The aggressive nature and high mortality rate of lung cancer underscore the imperative need for early diagnosis of the disease.Thus,aminopeptidase N(APN),a potential biomarker for lung cancer,should be thoroughly investigated in this context.This report describes the development of HA-apn,a novel near-infrared fluorescent probe,specifically engineered for the sensitive detection of endogenous APN.Characterized by its high selectivity,straightforward molecular architecture,and suitable optical properties,including a long-wavelength emission at 835 nm and a large Stokes shift of 285 nm,HA-apn had high efficacy in identifying overexpressed APN in tumor cells,which shows its potential in pinpointing malignancies.To further validate its applicability and effectiveness in facilitating the direct and enhanced visualization of pulmonary alterations,an in situ lung cancer mouse model was employed.Notably,HAapn was applied for in vivo imaging of APN activity in the lung cancer mouse model receiving the probe through aerosol inhalation,and rapid and precise diagnostic results were achieved within 30min postadministration.Overall,HA-apn can be applied as an effective,non-intrusive tool for the rapid and accurate detection of pulmonary conditions.
基金supported by the National Natural Science Foundation of China(Nos.22225806,22078314,22278394,22378385)Dalian Institute of Chemical Physics(Nos.DICPI202142,DICPI202436)。
文摘Red fluorescent proteins with large Stokes shift(LSS-RFPs)are advantageous for multicolor imaging applications that allow simultaneous visualizations of multiple biological events.But it is difficult to develop LSS-RFPs by extending the emission wavelength of RFPs to far-red region.Here,we employed Forster resonance energy transfer(FRET)strategy to engineer the far-red fluorescent proteins with large Stokes shift.LSS-m Apple and LSS-mCherry were constructed by fusing HaloTag to m Apple and mCherry,allowing the fluorophore TMSi R to be connected to these RFPs.FRET between RFPs and TMSi R enabled them to apply the excitation of donor RFPs to emit far-red fluorescence of acceptor TMSi R.The Stokes shifts of LSS-m Apple and LSS-mCherry were 97 nm and 75 nm,respectively.The high FRET efficiency of LSS-mCherry(E_(FRET)=83.7%)can greatly reduce the fluorescence from the donor channel,which did not affect co-imaging with mCherry.In addition,LSS-mCherry also showed excellent photostability(t_(1/2)=449.3 s),enabling stable confocal fluorescence imaging for 15 min under continuous strong excitation.Furthermore,LSS-mCherry was applied for fluorescence labeling and imaging of the nucleus,mitochondria,lysosomes,and endoplasmic reticulum in living cells.Finally,we applied LSS-mCherry to perform multi-color bioimaging of 2–4 channels,and there was no obvious crosstalk between these channels.
基金financial support provided by National Natural Science Foundation of China(Nos.21775005,41430641 and 41140032)the Start-Up Fund of Qingdao University of Science and Technology(No.12030430010883)。
文摘As a hydrolase,chymotrypsin(CHT)is involved in many physiological activities,and its abnormal activity is closely related to diabetes,pancreatic fibrosis,chronic pancreatitis and pancreatic cancer.In this work,an innovative long-wavelength emission fluorescent probe TCF-CHT was designed and synthesized for the high specificity detection of CHT,which utilized TCF-OH and a mimetic peptide substrate 4-bromobutyryl as chromogenic group and recognition group,respectively.TCF-CHT exhibited excellent selectivity and eye-catching sensitivity(8.91 ng/m L)towards CHT,“off-on”long-wavelength emission at 670 nm and large Stokes shift(140 nm).Furthermore,the successful fulfillment and perfect performance in imaging endogenous CHT in complex organisms(P815 cells,HepG2 cells,zebrafish and tumor-bearing mice)verified its potential as a powerful tool for the recognition of CHT in complicated biological environments.
文摘The Stokes shift response function, which is related to the time dependent solvation energy, is calculated with the dielectric response function and a novel expression of nonequilibrium solvation energy. In the derivation, relationship between the polarization and the dielectric response function is used. With the dipole-in-a-sphere model applied to the system coumarin 343 and water as the solvent, encouraging agreement with the experimental data from Jimenez et al. is obtained [Nature 369, 471 （1994）].
基金support from National Natural Science Foundation of China (Nos. 21676113, 21402057, 21472059, 81671803)Youth Chen-Guang Project of Wuhan (2016070204010098)+2 种基金the 111 Project B17019the Ministry Province Jointly Constructed Base for State Key Lab-Shenzhen Key Laboratory of Chemical Biology, Shenzhensupported by Self-determined Research Funds of CCNU from the colleges’ basic research and operation of MOE (No. CCNU16A02004)
文摘Developing the novel fluorescent dyes with a larger Stokes shift is still a challenge in the research of fluorescence probes. In this work, a naphthalimide-modified near-infrared cyanine dye with an emission at 785 nm has been synthesized for lysosome-targeting imaging. This fluorescent dye showed a large Stokes shift（up to 165 nm） and favorable lysosome-targeting property, which facilitated it to be a potential candidate for studying of lysosomal functions. The result also indicated that the probe is a promising contrast agent for in vivo imaging in mouse models.
基金the National Natural Science Foundation of China(Nos.21877029,21735001)the National Key R&D Program of China(No.2019YFA0210103)+1 种基金the National Postdoctoral Program for Innovative Talents(No.BX20190110)the China Postdoctoral Science Foundation(No.2019M662758)。
文摘Fluorescent probes have been widely employed in biological imaging and sensing.However,it is always a challenge to design probes with high sensitivity.In this work,based on rhodamine skeleton,we developed a general strategy to construct sensitivity-enhanced fluorescent probe with the help of theoretical calculation for the first time.As a proof of concept,we synthesized a series of HOCl probes.Experiment results showed that with the C-9 of pyronin moiety of rhodamine stabilized by an electron donor group,probe DQF-S exhibited an importantly enhanced sensitivity(LOD:0.2 nmol/L)towards HOCl together with fast response time(<10 s).Moreover,due to the breaking symmetrical electron distribution by another electron donor group,the novel rhodamine probe DQF-S displayed a far red to near-infrared emission(>650 nm)and large Stokes shift.Bioimaging studies indicated that DQF-S can not only effectively detect basal HOCl in various types of cells,but also be successfully applied to image tumor tissue in vivo.These results demonstrate the potential of our design as a useful strategy to develop excellent fluorescent probes for bioimaging.
基金This work was supported by the Science Technology and Innovation Committee of Shenzhen Municipality(JCYJ20180507181654823)the National Natural Science Foundation of China(21778044)and Sichuan Science and Technology Program(2018JY0360).
文摘Hydrogen peroxide(H2O2)plays a significant role in regulating a variety of biological processes.Dysregulation of H2O2 can lead to various diseases.Although numerous fluorescent imaging probes for H2O2 have been reported,the development of H2O2 ratiometric fluorescent probe with large Stokes shift remains rather limited.Such probes have shown distinct advantages,such as minimized interference from environment and improved signal-to noise ratio.In this work,we reported a new pyrene-based compound Py-VPB as H2O2 fluorescent probe in vitro.The probe demonstrated ratiometric detection behavior,large Stokes shift and large emission shift.In addition,the probe showed high sensitivity and selectivity towards H2O2 in vitro.Based on these excellent properties,we successfully applied Py-VPB to the visualization of exogenous and endogenous H2O2 in living cells.Cell imaging study also showed that our probe was localized in the mitochondria.We envision that the probe can provide a useful tool for unmasking the biological roles of mitochondrial H2O2 in living systems.
基金supported by the National Natural Science Foundation of China (Nos. 22074036, 22004033, 21877029)the National Postdoctoral Program for Innovative Talents (No. BX20190110)the China Postdoctoral Science Foundation (No. 2019M662758)。
文摘Rhodamine dyes have been widely employed in biological imaging and sensing. However, it is always a challenge to design rhodamine derivatives with huge Stokes shift to address the draconian requirements of single-excitation multicolor imaging. In this work, we described a generally strategy to enhance the Stokes shift of rhodamine dyes by completely breaking their electronic symmetry. As a result, the Stokes shift of novel rhodamine dye DQF-RB-Cl is up to 205 nm in PBS, which is the largest in all the reported rhodamine derivatives. In addition, we successfully realized the single excitation trichromatic imaging of mitochondria, lysosomes and cell membranes by combining DQF-RB-Cl with commercial lysosomal targeting probe Lyso-Tracker Green and membrane targeting dye Dil. This is the organic synthetic dyes for SLE-trichromatic imaging in cells for the first time. These results demonstrate the potential of our design as a useful strategy to develop huge Stokes shift fluorophore for bioimaging.
基金supported by US National Science Foundation(CHE-1565520) to X. Lifunded by the STF at the University of Washingtonthe National Science Foundation (MRI-1624430).
文摘Chrornophore structures inspired by natural green fluorescent protein （GFP） play an im- portant role in the field of bio-irnaging. In this work, photochemical properties of a new class of GFP-like chromophores are investigated using computational approaches. Thermo- dynamically stable isomers are identified in vacuum and in solvent. Spectral Stokes shifts are computed and compared to experiments. An inverted solvatochromic shift between absorption and emission emerging in this new class of GFP-like chromophores is observed, and attributed to the stabilized charge transfer and inhibited rotational structural reorganization in solvent.
基金supported by Natural Science Foundation of Zhejiang Province(LQ21C200002)Zhejiang Provincial Key Research and Development Program(2021CO2062,2022C02028)Key Research and Development Program of Ningbo(2021Z056,2022S163)
文摘Herein,the 2,4-dinitrophenyl functional group acting as the thiophenol reactive site was introduced into a carbazole-chalcone fluorophore to synthesize probe-CCF2,which could result in a remarkable increase in fluorescence when reacting with thiophenols.The selectivity and accuracy of probe-CCF2 were investigated with thiophenols,hydrosulphide salt,aliphatic thiols,glutathione,cysteine,anions and metal cations.Probe-CCF2 exhibited a detection limit of 37 nmol/L(R^(2)=0.9951),a remarkable Stokes shift of approximately 130 nm,and a brief response time of 9 min with a remarkable increase in fluorescence of 90-fold.Probe-CCF2 was applied for thiophenol detection in water samples and imaging in living cells successfully,with high sensitivity and excellent selectivity.
文摘A simple, mild and efficient one-pot approach for the construction of 2-aryl-3-nitro-2,9-dihydrothiopyrano- [2,3-b]indole derivatives has been realized in CH2C12 medium at ambient temperature via three-component tandem reaction of N-protected-2-chloro-3-formylindoles, sodium hydrosulfide and β-substituted nitroolefins/δ-substituted nitrodienes using DABCO （10 mol%） as an organocatalyst, followed by dehydration in the presence of activated molecular sieves （4 A）. The significant advantages of this protocol are simple operation, shorter reaction time, high atom economy, good to high yields （73%-89%） and wider substrate scope. In addition, all the synthesized com- pounds have shown the large positive Stokes shift values （5632-6081 cm ^-1）.
基金the Qingdao Municipal People’s Livelihood Science and Technology Project(No.17-3-3-76-nsh)the National Natural Science Foundation of China(No.21673294)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2019ZD17)the Key Technologies R&D Program of Shandong Province(No.2019GSF108159).
文摘During the last decade,a great variety of ligand protected gold nanoclusters(AuNCs)have been synthesized,and their broad applications have been intensively reported.Although the spectroscopic properties of AuNCs have been comprehensively explored,the mechanism of the significant Stokes shift(>200 nm)and the specific role played by surface ligands have not been clearly explained yet.In this study,a series of fluorescent AuNCs with huge Stokes shift(up to 530 nm)were successfully prepared by employing the rationally designed tri-peptides as the protecting ligands,and their spectroscopic properties were systematically investigated.The detailed measurements on the example product,YCY-AuNCs(Tyr-Cys-Tyr liganded AuNCs),showed that the energy absorbed by the tyrosine(~250 nm)can be effectively transferred through the ligand-mediated two-step Förster resonance energy transfer(FRET)process and released as fluorescence emission in the near-infrared fluorescence(NIR)range(~780 nm),which resulted in the significant apparent Stokes shift.The YCY ligands play a critical role by offering the tyrosine groups(donor of the first FRET pair),generating the dityrosine-like structure on the AuNCs surface(acceptor of the first FRET pair and donor of the second FRET pair),and protecting the cores(acceptor of the second acceptor).The additional ligand exchange experiments and the investigation on the other AuNCs further demonstrated that the sufficient high density of the aromatic groups is also essential to mediate the two-step FRET and achieve the remarkable Stokes shift.We believe that the aromatic ligand-mediated FRET mechanism not only offers a new theoretical explanation for the huge Stokes shift exhibited in AuNCs,but also provides a general strategy for the construction of new materials with large Stokes shift.
基金supported by the Shandong Provincial Natural Science Foundation,China(No.ZR2020MA078)。
文摘Four benzocoumarin-based two-photon fluorescent probes(BH1-BH4)are proposed for ra-tiometric detection of hypochlorous acid(HClO)and their two-photon sensing perfor-mance are evaluated by means of time-dependent density func-tional theory and quadratic re-sponse theory.The effects of benzene-fused position on Stokes shift,fluorescence quantum yield and two-photon absorption are discussed comprehensively.The results show that fusing a benzene ring in coumarin can enhance Stokes shift efficiently.The benzene-fused position has important effects on these photophysical properties.The benzo[g]coumarins(BH1)and benzo[f]coumarins(BH2)derivatives have larger Stokes shifts in comparison with benzo[h]coumarins(BH3)and dihydrophenazine(BH4)derivatives.The two-photon absorp-tion of benzo[f]coumarins(BH2)derivative is much smaller than those of other benzo-coumarins derivatives.The large Stokes shift and increased two-photon action cross section can be achieved simultaneously in the dihydrophenazine(BH4)derivative.Therefore,the de-signed BH4 is expected to have superior performance for the ratiometric detection of HClO.To explore the reasons behind these effects,the intramolecular charge transfer degrees are il-lustrated quantitatively by plotting the hole-electron isosurface map,and the relation be-tween charge transfer and Stokes shift is revealed.A two-state model analysis is employed to understand two-photon absorption ability.Moreover,the fluorescence near-quenching mecha-nism of the product molecules B1 and B3 is explained by analyzing reorganization energy and Huang-Rhys factor,as well as related normal mode.Our research could contribute to the effi-cient design of ratiometric two-photon fluorescent probes with large Stokes shift and signifi-cant two-photon action cross section.
基金National Natural Science Foundation of China(Nos.22107029,22377135,22305178,92253306 and 82130099)the Taishan Scholars Program(No.tsqn202312305)+7 种基金the Young Elite Scientists Sponsorship Program by Chinese Chemical Societythe Fundamental Research Projects of Science&Technology Innovation and development Plan in Yantai City(No.2023JCYJ059)the Shandong Laboratory Program(No.SYS202205)the Fundamental Research Funds for the Central Universities(No.222201717003)the Programme of Introducing Talents of Discipline to Universities(No.B16017)the Open Funding Project of the State Key Laboratory of Bioreactor Engineeringthe State Key Laboratory of Drug Research(No.SKLDR-2023-KF-10)the Ministry of Education Key Laboratory on signaling Regulation and Targeting Therapy of Liver Cancer(Naval Medical University)(No.2023-MEKLLCMS/ZD-00*)。
文摘Non-alcoholic fatty liver disease(NAFLD)is prevalent worldwide as a chronic liver disease that not only gives rise to hepatic complications,but leads to other chronic diseases such as type 2 diabetes and atherosclerosis.The aberrant accumulation of lipid droplets(LDs)in hepatocytes is a prominent signature of NAFLD.However,conventional techniques lack the capability to effectively monitor the dynamic changes in LD levels during NAFLD with living organisms.Hence,it is imperative to develop LD-specific long-wavelength fluorescent probes with high imaging contrast for the in-situ diagnosis of NAFLD.In this study,we synthesized a new LD-selective long-wavelength fluorescent probe,denoted as LD-1,based on the twisted intramolecular charge transfer(TICT)mechanism.The probe exhibits a large Stokes shift and intensive fluorescence emission in nonpolar and viscous solutions.By self-assembling LD-1 with bovine serum albumin(BSA),a biocompatible,long-wavelength fluorescent probe hybrid,LD-1@BSA,was formed,allowing for LDs to be selectively imaged in hepatocytes.Moreover,LD-1@BSA successfully discriminates NAFLD cells before and after drug treatment,and achieves non-invasive and real-time monitoring of LD accumulation in a mouse model of NAFLD.
基金grateful for the support by the National Natural Science Foundation of China(Nos.21702013,22271010)。
文摘An array of pyridine-ester enolate based organoboron complexes has been designed and synthesized via a one-pot cascade of Pd-catalyzedα-arylation and BF2complexation.The rapid structure-activity relationship(SAR)studies indicated that unsymmetrical N,O-chelated BF2complexes were highly fluorescent in solid state,and exhibited large Stokes shifts,excellent photostability,along with insensitivity to p H.Theα-aryl group could not only modulate the electronic effect but also inhibit the intermolecularπ-πstacking to promote the aggregation-induced emission(AIE)effect.DFT calculations and experiments identified that the intramolecular charge transfer properties of these N,O-chelates could be switched by the modification of substituents,resulting tunable fluorescence wavelengths.Furthermore,post-complexation modification was accomplished,including Suzuki-Miyaura cross-coupling,Buchwald-Hartwig amination,oxidative cleavage,along with a unique triple substitution reaction involving propargyl Grignard reagents.The exemplificative application of dimethylamine substituted boron complex as a reversible acidic vapor sensor was also demonstrated.
基金supported by the National Natural Science Foundation of China(Nos.22077099 and 22171223)the Innovation Capability Support Program of Shaanxi(Nos.2023-CX-TD-75 and 2022KJXX-32)+4 种基金the Technology Innovation Leading Program of Shaanxi(Program No.2023KXJ-209)the Natural Science Basic Research Program of Shaanxi(Nos.2022JQ-151 and 2023-JC-YB-141)Young Talent Fund of Association for Science and Technology in Shaanxi,China(No.SWYY202206)the Shaanxi Fundamental Science Research Project for Chemistry&Biology(Nos.22JHZ010 and 22JHQ080)the Yan’an City Science and Technology Project(No.2022SLZDCY-002).
文摘Sulfydryl-contained(-SH)substances including hydrogen sulfide(H_(2)S),cysteine(Cys),homocysteine(Hcy)and glutathione(GSH)play crucial roles in living systems,and their variations are closely associated with various diseases.Herein,we developed a near-infrared intramolecular charge transfer(ICT)based fluorescent probe Y-NBD,achieving detection of Cys/Hcy and H_(2)S with different fluorescent signals(green-red for Cys/Hcy,red for H_(2)S),large Stokes shifts(∼100/105nm or 191 nm)and high signal-background-ratio,but not responding to GSH.Y-NBD was successfully applied to image exogenous/endogenous Cys/Hcy and H_(2)S in various living cancer cells(HeLa,A549,and HepG2)and in zebrafish.It not only visualized the transformation pathway of several thiols in HepG2 cells but also verified that the intestine is the main site for the activation and metabolism of Y-NBD in zebrafish,as well as realized to evaluate the degree of drug-induced liver injury.This work provides a promising tool for imaging Cys/Hcy and H_(2)S in living systems and shows great potency in evaluating drug-induced liver injury and its treatment.
基金supported by the National Natural Science Foundation of China(Nos.22077099 and 22171223)the Technology Innovation Leading Program of Shaanxi(No.2020TG-031)+3 种基金the Innovation Capability Support Program of Shaanxi(Nos.2023-CXTD-75 and 2022KJXX-32)the Natural Science Basic Research Program of Shaanxi(No.2023-JC-YB-141)Young Talent Fund of Association for Science and Technology in Shaanxi,China(No.SWYY202206)the Natural Science Basic Research Plan in Shaanxi Province of China(Nos.2022JQ-151 and 2022JQ-125).
文摘Thiophenol(PhSH)is an important raw material for organic synthesis,while its high toxicity to organisms makes it an environmental pollutant.Therefore,it is crucial to accurately detect PhSH and explore its metabolic process in the living system.Herein,a near-infrared(NIR)fluorescent probe TEM-FB was developed for sensing PhSH with a turn-on fluorescent signal at 719nm and a large Stokes shift(198 nm)based on generating the intramolecular charge transfer(ICT)process.TEM-FB shows high specificity and significant sensitivity towards PhSH(detection limit:10 nmol/L)via the aromatic nucleophilic substitution mechanism.Furthermore,it was successfully applied to image PhSH in multiple cell lines and in zebrafish.Notably,we revealed the oxidative stress process caused by PhSH and demonstrated that the hydrogen peroxide(H_(2)O_(2))in cells would alleviate the poisonousness from exogenous PhSH for the first time.This work provides a promising bioimaging tool for monitoring PhSH in living systems and visualizing the process of oxidative stress induced by PhSH.
文摘Traditional ligand-field theory has to be improved by taking into account both 'pure electronic' contribution and electron-phonon interaction one (including lattice-vibrational relaxation energy). By means of improved ligand-field theory, R1, R2, R'3, R'2, and R'1 lines, U band, ground-state zero-field-splitting (GSZFS), and ground-state g factors of ruby and/or GSGG: Cr3+ as well as thermal shifts of GSZFS, R1 line and R2 line of ruby have been calculated.The results are in very good agreement with the experimental data. Moreover, it is found that the value of cubic-field parameter given by traditional ligand-field theory is inappropriately large. For thermal shifts of GSZFS, R1 line and R2 line of ruby, several conclusions have also been obtained.
基金the National Natural Science Foundation of China(Nos.21274016 and 21072026)Fundamental Research Funds for the Central Universities(No.DUT13LK06)for financial support to this work
文摘Two novel thieno-[3,4-b]-pyrazine-based molecules, TP-E and TP-O, were designed and synthesized for potential application as red fluorescent emitters. The bulky tetraphenylethylene groups were attached at the periphery of the thieno-[3,4-b]-pyrazine core to form the non-planar molecules, as efficient solid- state emitting materials. The peripheral groups were grafted to the emissive core through either a conjugated acetylene bond, or a non-conjugated ether bond. These molecules exhibit strnng red fluorescence in both dilute solutions and in thin films with large Stokes shifts of over 100 nm. The cyclic voltammetry measurements showed the reversible oxidation and reduction behavior for both compounds. All these properties indicate the two compounds are possible functional materials for use in ontoelectronic devices.
基金financial support from National Natural Science Foundation of China(Nos.20776165, 20702065,20872184)We would thank"the Foundation of Chongqing Science and Technology Commission"(Nos. CSTC2008BA4020,CSTC2009BB4216)
文摘This letter presents excited state intramolecular proton transfer (ESIPT) of new conjugated derivatives containing hydroxy and imino groups. ESIPT occurrence in one photon process is confirmed by well-separated emission band for the derivatives. Two- photon absorption (TPA) induced ESIPT emission has been determined by Ti:sapphire femtosecond laser tuning from 700 nrn to 800 nm at the internals of 20 nm.
