Intramolecular charge transfer(ICT) dual fluorescence of p-dimethylamino-benzoylhydrazine(DMABH) in acetonitrile was found to show a highly selective response to HSO - 4 over several other anions. The intensity ratio ...Intramolecular charge transfer(ICT) dual fluorescence of p-dimethylamino-benzoylhydrazine(DMABH) in acetonitrile was found to show a highly selective response to HSO - 4 over several other anions. The intensity ratio of the CT to LE emission and the total fluorescence intensity of DMABH decreased with increasing bisulfate concentration. While the dual fluorescence response was very similar to that of DMABA at a low HSO - 4 concentration, the CT intensity decreased drastically and the LE intensity remained almost constant, however, the difference was observed at a high HSO - 4 concentration, in which both the CT and LE intensities of DMABH decreased. A different recognition mechanism from that of DMABA was suggested for DMABH in which hydrogen bonding and protonization were the recognition interactions at low and high HSO - 4 concentrations, respectively.展开更多
Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a fac...Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a facile method to prepare green and NIR dual-mode afterglow of carbon dots(CDs) through in situ embedding o-CDs(being prepared from o-phenylenediamine) into cyanuric acid(CA) matrix(named o-CDs@CA). Further studies reveal that the green and NIR afterglows of o-CDs@CA originate from thermal activated delayed fluorescence(TADF) and room temperature phosphorescence(RTP) of o-CDs,respectively. In addition,the formation of covalent bonds between o-CDs and CA,and the presence of multiple fixation and rigid e ects to the triplet states of o-CDs are confirmed to be critical for activating the observed dual-mode afterglow. Due to the shorter lifetime and insensitiveness to human vision of the NIR RTP of o-CDs@CA,it is completely covered by the green TADF during directly observing. The NIR RTP signal,however,can be readily captured if an optical filter(cut-o wavelength of 600 nm) being used. By utilizing these unique features,the applications of o-CDs@CA in anti-counterfeiting and information encryption have been demonstrated with great confidentiality. Finally,the as-developed method was confirmed to be applicable to many other kinds of CDs for achieving or enhancing their afterglow performances.展开更多
High-performance nondoped organic light-emitting diodes(OLEDs)are promising technologies for future commercial applications.Herein,we synthesized two new thermally activated delayed fluorescence(TADF)emitters that ena...High-performance nondoped organic light-emitting diodes(OLEDs)are promising technologies for future commercial applications.Herein,we synthesized two new thermally activated delayed fluorescence(TADF)emitters that enable us,for the first time,to combine three effective approaches for enhancing the efficiency of nondoped OLEDs.First,the two emitters are designed to have high steric hindrances such that their emitting cores will be suitably isolated from those of their neighbors to minimize concentration quenching.On the other hand,each of the two emitters has two stable conformations in solid films.In their neat films,molecules with the minority conformation behave effectively as dopants in the matrix composing of the majority conformation.One hundred percent exciton harvesting is thus theoretically feasible in this unique architecture of“self-doped”neat films.Furthermore,both emitters have relatively high aspect ratios in terms of their molecular shapes.This leads to films with preferred molecular orientations enabling high populations of horizontal dipoles beneficial for optical outcoupling.With these three factors,OLEDs with nondoped emitting layers of the respective emitters both achieve nearly 100%exciton utilization and deliver over 30%external quantum efficiencies and ultralow efficiency roll-off at high brightness,which have not been observed in reported nondoped OLEDs.展开更多
Dual fluorescence at ca . 447 nm and 545 nm was observed from the aqueous 1 naphthylamine (NA) solutions at pH higher than 13 6. Similar dual fluorescence was also found with sodium 1 naphthylaminoacetate(NAA) , but n...Dual fluorescence at ca . 447 nm and 545 nm was observed from the aqueous 1 naphthylamine (NA) solutions at pH higher than 13 6. Similar dual fluorescence was also found with sodium 1 naphthylaminoacetate(NAA) , but not with N, N disubstituted 1 aminonaphthalenes such as sodium 1 naphthylaminodiacetate(NADA) and 1 dimethylaminonaphthalene(DMAN). No change in absorption spectra of NA and NAA was observed in this pH region.It was proposed that the dual fluorescence observed with NA and NAA was due to the excited state dissociation of the primary and secondary amines at high pH. From the dual fluorescence intensity ratio pH titration curve, the p K * as of NA and NAA were estimated to be between 14 and 15 which are much lower than the ground state p K a. The novel approatch is such a simple, convenient and frequent analysis technique that it can be widely used in detecting the substitutional derivatives of aminonaphthalene.展开更多
Single-molecule luminophores with dual-thermally activated delayed fluorescence(TADF)properties are receiving increasing attention.However,how to achieve these goals requires more in-depth studies.Herein,we demonstrat...Single-molecule luminophores with dual-thermally activated delayed fluorescence(TADF)properties are receiving increasing attention.However,how to achieve these goals requires more in-depth studies.Herein,we demonstrate a novel example emitter,10-(5-(2-(pyridin-3-yl)-[4,5′-bipyrimidin]-6-yl)pyridin-2-yl)-10Hphenoxazine(PmPy-PXZ),enabling dual-TADF properties due to its key feature of conformational isomerization.Introducing a pyridine bridge can greatly reduce the steric hindrance and facilitate dual-stable conformations in the ground state,where the quasi-axial(QA)forms predominate.Moreover,unlike previously reported TADF molecules with dual confirmations,both theoretical and experimental measurements show that not only the quasi-equatorial(QE)forms but also the QA forms exhibit distinct TADF characteristics,which can be attributed to an additional higher reverse intersystem crossing pathway.This is the first time that dual-TADF properties of single molecules have been achieved based on conformational isomerism.Its applications in“self-doping”organic light-emitting diode and biomedical imaging have further been investigated.All these results show the good potential of such dual-band TADF emitters based on molecular conformational isomerization.展开更多
Rheumatoid arthritis(RA)is a debilitating autoimmune disease that causes chronic pain and serious complications,presenting a significant challenge to treat.Promising approaches for treating RA involve signaling pathwa...Rheumatoid arthritis(RA)is a debilitating autoimmune disease that causes chronic pain and serious complications,presenting a significant challenge to treat.Promising approaches for treating RA involve signaling pathways modulation and targeted therapy.To this end,a multifunctional nanosystem,TPC-U@HAT,has been designed for RA therapy,featuring multitargeting,dual-stimuli response,and on-demand drug release capabilities.TPC-U@HAT is composed of a probe/prodrug TPC,a JAK1 kinase inhibitor upadacitinib,and the drug carrier HAT.TPC is composed of an aggregation-induced emission(AIE)-active NIR-II chromophore TPY and an NF-κB/NLRP3 inhibitor caffeic acid phenethyl ester(CAPE),connected via boronic ester bond which serves as the reactive-oxygen-species-responsive linker.The carrier,HAT,is created by grafting bone-targeting alendronate and hydrophobic tocopheryl succinate onto hyaluronic acid chains,which can encapsulate TPC and upadacitinib to form TPC-U@HAT.Upon intravenous injection into mice,TPC-U@HAT accumulates at inflamed lesions of RA through both active and passive targeting,and the overexpressed hyaluronidase and H_(2)O_(2) therein cleave the hyaluronic acid polymer chains and boronate bonds,respectively.This generates an AIE-active chromophore for detection and therapeutic evaluation of RA via both optoacoustic imaging and NIR-II fluorescent imaging and concomitantly releases CAPE and upadacitinib to exert efficacious therapy by inhibiting NF-κB/NLRP3 and JAK-STAT pathways.展开更多
Under hydrothermal environment,we synthesized lanthanide ions doped sodium yttrium fluoride(NaYF4:Er,Tm@NaYF4:Ce,Tb) luminescent microcrystals via an epitaxial growth technique.The structure and morphology of these mi...Under hydrothermal environment,we synthesized lanthanide ions doped sodium yttrium fluoride(NaYF4:Er,Tm@NaYF4:Ce,Tb) luminescent microcrystals via an epitaxial growth technique.The structure and morphology of these microcrystals were examined by SEM,TEM,EDS and XRD measurements.These particles show dual-mode emissions with red upconversion(UC) and green down conversion(DC) as single particles level.The mean length and diameter of these microparticles increase from 0.43 to2.26 μm and from 1.33 to 1.86 μm,respectively.Most interestingly,the photoluminescence properties of NaYF4:Er,Tm@NaYF4:Ce,Tb phosphor crystals are highly dependent on the crystallite size.The microcrystals fluoresce emit dual-mode emissions when they are solid or dispersed in solvents.Benefiting its intensive fluorescence and uniform morphology,these materials hold great potential for security and anti-counterfeiting applications.展开更多
Fluorescence-guided surgery(FGS)with tumor-targeted imaging agents,particularly those using the near-infrared wavelength,has emerged as a real-time technique to highlight the tumor location and margins during a surgic...Fluorescence-guided surgery(FGS)with tumor-targeted imaging agents,particularly those using the near-infrared wavelength,has emerged as a real-time technique to highlight the tumor location and margins during a surgical procedure.For accurate visualization of prostate cancer(PCa)boundary and lymphatic metastasis,we developed a new approach involving an efficient self-quenched near-infrared fluorescence probe,Cy-KUE-OA,with dual PCa-membrane affinity.Cy-KUE-OA specifically targeted the prostate-specific membrane antigen(PSMA),anchored into the phospholipids of the cell membrane of PCa cells and consequently showed a strong Cy7-de-quenching effect.This dual–membrane-targeting probe allowed us to detect PSMA-expressing PCa cells both in vitro and in vivo and enabled clear visualization of the tumor boundary during fluorescence-guided laparoscopic surgery in PCa mouse models.Furthermore,the high PCa preference of Cy-KUE-OA was confirmed on surgically resected patient specimens of healthy tissues,PCa,and lymph node metastases.Taken together,our results serve as a bridge between preclinical and clinical research in FGS of PCa and lay a solid foundation for further clinical research.展开更多
A novel thiazolothiazole-bridged imidazole derivative(1) was found to exhibit blue fluorescence in gaseous state or in methanol and yellow fluorescence in solid state. The N-alkylation of imidazole subunit(s) in 1 usi...A novel thiazolothiazole-bridged imidazole derivative(1) was found to exhibit blue fluorescence in gaseous state or in methanol and yellow fluorescence in solid state. The N-alkylation of imidazole subunit(s) in 1 using n-propyl iodide generated unsymmetrically or symmetrically alkylated thiazolothiazolebridged imidazolium salts with good water solubility and remarkably strong emission in solution. Furthermore, the replacement of iodide counter-anion by triflate or bis(trifluoromethane sulfonyl)imide achieved remarkably strong emission in solid state and in solution as well as good water solubility. The strong fluorescence of dicationic salts with triflate and NTf_(2)^(-)counter-anions in solid state can be ascribed to their twisted and rigid structures induced by interionic C-H···F hydrogen bonding.展开更多
A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized throug...A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers （FRET） from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.展开更多
Au-Se bond strategy has been applied to construct fluorescence nanoprobe that is being used to simultaneously dual-image the tumor markers matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-7(MMP-7)in vitro...Au-Se bond strategy has been applied to construct fluorescence nanoprobe that is being used to simultaneously dual-image the tumor markers matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-7(MMP-7)in vitro.The two Se-terminating ligand peptide chains respectively labeled with fluorescein isothiocyanate(FITC)and 5-Carboxytetramethylrhodamine(5-TAMRA)dyes are attached to the surface of Au nanoparticles(NPs).The nanoprobe can be specifically cut off by MMP-2 and MMP-7 respectively to carry out significant enhanced fluorescence recovery for simultaneously imaging both markers.The nanoprobe not only displays high selectivity and sensitivity towards MMP-2 and MMP-7,but also has strong anti-interference stability against biothiols and enhanced fidelity for avoiding"false positive"results.This approach offers new perspectives in designing tumor-related early diagnosis approaches and also provides strategies for clinical applications.展开更多
文摘Intramolecular charge transfer(ICT) dual fluorescence of p-dimethylamino-benzoylhydrazine(DMABH) in acetonitrile was found to show a highly selective response to HSO - 4 over several other anions. The intensity ratio of the CT to LE emission and the total fluorescence intensity of DMABH decreased with increasing bisulfate concentration. While the dual fluorescence response was very similar to that of DMABA at a low HSO - 4 concentration, the CT intensity decreased drastically and the LE intensity remained almost constant, however, the difference was observed at a high HSO - 4 concentration, in which both the CT and LE intensities of DMABH decreased. A different recognition mechanism from that of DMABA was suggested for DMABH in which hydrogen bonding and protonization were the recognition interactions at low and high HSO - 4 concentrations, respectively.
基金the National Natural Science Foundation of China (52003284,51872300 and U1832110)the China Postdoctoral Science Foundation (BX20190338)S&T Innovation 2025 Major Special Program of Ningbo (2018B10054) for financially supporting this work。
文摘Near-infrared(NIR),particularly NIR-containing dual-/multimode afterglow,is very attractive in many fields of application,but it is still a great challenge to achieve such property of materials. Herein,we report a facile method to prepare green and NIR dual-mode afterglow of carbon dots(CDs) through in situ embedding o-CDs(being prepared from o-phenylenediamine) into cyanuric acid(CA) matrix(named o-CDs@CA). Further studies reveal that the green and NIR afterglows of o-CDs@CA originate from thermal activated delayed fluorescence(TADF) and room temperature phosphorescence(RTP) of o-CDs,respectively. In addition,the formation of covalent bonds between o-CDs and CA,and the presence of multiple fixation and rigid e ects to the triplet states of o-CDs are confirmed to be critical for activating the observed dual-mode afterglow. Due to the shorter lifetime and insensitiveness to human vision of the NIR RTP of o-CDs@CA,it is completely covered by the green TADF during directly observing. The NIR RTP signal,however,can be readily captured if an optical filter(cut-o wavelength of 600 nm) being used. By utilizing these unique features,the applications of o-CDs@CA in anti-counterfeiting and information encryption have been demonstrated with great confidentiality. Finally,the as-developed method was confirmed to be applicable to many other kinds of CDs for achieving or enhancing their afterglow performances.
基金National Natural Science Foundation of China,Grant/Award Numbers:51821002,52003185,52003186,52130304National Key Research&Development Program of China,Grant/Award Numbers:2020YFA0714601,2020YFA0714604+2 种基金Suzhou Key Laboratory of Functional Nano&Soft MaterialsCollaborative Innovation Center of Suzhou Nano Science&Technologythe 111 Project。
文摘High-performance nondoped organic light-emitting diodes(OLEDs)are promising technologies for future commercial applications.Herein,we synthesized two new thermally activated delayed fluorescence(TADF)emitters that enable us,for the first time,to combine three effective approaches for enhancing the efficiency of nondoped OLEDs.First,the two emitters are designed to have high steric hindrances such that their emitting cores will be suitably isolated from those of their neighbors to minimize concentration quenching.On the other hand,each of the two emitters has two stable conformations in solid films.In their neat films,molecules with the minority conformation behave effectively as dopants in the matrix composing of the majority conformation.One hundred percent exciton harvesting is thus theoretically feasible in this unique architecture of“self-doped”neat films.Furthermore,both emitters have relatively high aspect ratios in terms of their molecular shapes.This leads to films with preferred molecular orientations enabling high populations of horizontal dipoles beneficial for optical outcoupling.With these three factors,OLEDs with nondoped emitting layers of the respective emitters both achieve nearly 100%exciton utilization and deliver over 30%external quantum efficiencies and ultralow efficiency roll-off at high brightness,which have not been observed in reported nondoped OLEDs.
文摘Dual fluorescence at ca . 447 nm and 545 nm was observed from the aqueous 1 naphthylamine (NA) solutions at pH higher than 13 6. Similar dual fluorescence was also found with sodium 1 naphthylaminoacetate(NAA) , but not with N, N disubstituted 1 aminonaphthalenes such as sodium 1 naphthylaminodiacetate(NADA) and 1 dimethylaminonaphthalene(DMAN). No change in absorption spectra of NA and NAA was observed in this pH region.It was proposed that the dual fluorescence observed with NA and NAA was due to the excited state dissociation of the primary and secondary amines at high pH. From the dual fluorescence intensity ratio pH titration curve, the p K * as of NA and NAA were estimated to be between 14 and 15 which are much lower than the ground state p K a. The novel approatch is such a simple, convenient and frequent analysis technique that it can be widely used in detecting the substitutional derivatives of aminonaphthalene.
基金supported by the National Natural Science Foundation of China(grant nos.52003186,52130304,51821002,and 52003185)the National Key Research and Development Program of China(grant nos.2020YFA0714601 and 2020YFA0714604)+1 种基金the Science and Technology Project of Suzhou(grant no.ZXL2022490)the Suzhou Key Laboratory of Functional Nano&Soft Materials,the Collaborative Innovation Center of Suzhou Nano Science and Technology,and the 111 Project.
文摘Single-molecule luminophores with dual-thermally activated delayed fluorescence(TADF)properties are receiving increasing attention.However,how to achieve these goals requires more in-depth studies.Herein,we demonstrate a novel example emitter,10-(5-(2-(pyridin-3-yl)-[4,5′-bipyrimidin]-6-yl)pyridin-2-yl)-10Hphenoxazine(PmPy-PXZ),enabling dual-TADF properties due to its key feature of conformational isomerization.Introducing a pyridine bridge can greatly reduce the steric hindrance and facilitate dual-stable conformations in the ground state,where the quasi-axial(QA)forms predominate.Moreover,unlike previously reported TADF molecules with dual confirmations,both theoretical and experimental measurements show that not only the quasi-equatorial(QE)forms but also the QA forms exhibit distinct TADF characteristics,which can be attributed to an additional higher reverse intersystem crossing pathway.This is the first time that dual-TADF properties of single molecules have been achieved based on conformational isomerism.Its applications in“self-doping”organic light-emitting diode and biomedical imaging have further been investigated.All these results show the good potential of such dual-band TADF emitters based on molecular conformational isomerization.
基金NSFC,Grant/Award Numbers:22274057,21875069,21788102Guangdong Provincial Basic and Applied Basic Research Fund Regional Joint Fund Project(Youth Fund Project),Grant/Award Number:2022A1515110842Chinese Postdoctoral Science Foundation,Grant/Award Number:2022M711194。
文摘Rheumatoid arthritis(RA)is a debilitating autoimmune disease that causes chronic pain and serious complications,presenting a significant challenge to treat.Promising approaches for treating RA involve signaling pathways modulation and targeted therapy.To this end,a multifunctional nanosystem,TPC-U@HAT,has been designed for RA therapy,featuring multitargeting,dual-stimuli response,and on-demand drug release capabilities.TPC-U@HAT is composed of a probe/prodrug TPC,a JAK1 kinase inhibitor upadacitinib,and the drug carrier HAT.TPC is composed of an aggregation-induced emission(AIE)-active NIR-II chromophore TPY and an NF-κB/NLRP3 inhibitor caffeic acid phenethyl ester(CAPE),connected via boronic ester bond which serves as the reactive-oxygen-species-responsive linker.The carrier,HAT,is created by grafting bone-targeting alendronate and hydrophobic tocopheryl succinate onto hyaluronic acid chains,which can encapsulate TPC and upadacitinib to form TPC-U@HAT.Upon intravenous injection into mice,TPC-U@HAT accumulates at inflamed lesions of RA through both active and passive targeting,and the overexpressed hyaluronidase and H_(2)O_(2) therein cleave the hyaluronic acid polymer chains and boronate bonds,respectively.This generates an AIE-active chromophore for detection and therapeutic evaluation of RA via both optoacoustic imaging and NIR-II fluorescent imaging and concomitantly releases CAPE and upadacitinib to exert efficacious therapy by inhibiting NF-κB/NLRP3 and JAK-STAT pathways.
基金Project supported by the National Natural Science Foundation of China (21271074,51372091)the Teamwork Projects funded by the Guangdong Natural Science Foundation (S2013030012842)+1 种基金Guangdong Provincial Science&Technology Project (2015B090903074)Guangzhou Science&Technology Project (201605030005)。
文摘Under hydrothermal environment,we synthesized lanthanide ions doped sodium yttrium fluoride(NaYF4:Er,Tm@NaYF4:Ce,Tb) luminescent microcrystals via an epitaxial growth technique.The structure and morphology of these microcrystals were examined by SEM,TEM,EDS and XRD measurements.These particles show dual-mode emissions with red upconversion(UC) and green down conversion(DC) as single particles level.The mean length and diameter of these microparticles increase from 0.43 to2.26 μm and from 1.33 to 1.86 μm,respectively.Most interestingly,the photoluminescence properties of NaYF4:Er,Tm@NaYF4:Ce,Tb phosphor crystals are highly dependent on the crystallite size.The microcrystals fluoresce emit dual-mode emissions when they are solid or dispersed in solvents.Benefiting its intensive fluorescence and uniform morphology,these materials hold great potential for security and anti-counterfeiting applications.
基金supported by the National Natural Science Foundation of China(NSFC)projects(22122705,22077139 and 81972400)CAMS Innovation Fund for Medical Sciences(CIFMS)(2021-I2M-1-054 and 2021-I2M-1-015)Beijing Outstanding Young Scientist Program(BJJWZYJH01201910023028,China).
文摘Fluorescence-guided surgery(FGS)with tumor-targeted imaging agents,particularly those using the near-infrared wavelength,has emerged as a real-time technique to highlight the tumor location and margins during a surgical procedure.For accurate visualization of prostate cancer(PCa)boundary and lymphatic metastasis,we developed a new approach involving an efficient self-quenched near-infrared fluorescence probe,Cy-KUE-OA,with dual PCa-membrane affinity.Cy-KUE-OA specifically targeted the prostate-specific membrane antigen(PSMA),anchored into the phospholipids of the cell membrane of PCa cells and consequently showed a strong Cy7-de-quenching effect.This dual–membrane-targeting probe allowed us to detect PSMA-expressing PCa cells both in vitro and in vivo and enabled clear visualization of the tumor boundary during fluorescence-guided laparoscopic surgery in PCa mouse models.Furthermore,the high PCa preference of Cy-KUE-OA was confirmed on surgically resected patient specimens of healthy tissues,PCa,and lymph node metastases.Taken together,our results serve as a bridge between preclinical and clinical research in FGS of PCa and lay a solid foundation for further clinical research.
基金National Natural Science Foundation of China(Nos.U20041101,21772034,U1704251)the Top-notch Personnel Fund of Henan Agricultural University(No.30500418)for financial support。
文摘A novel thiazolothiazole-bridged imidazole derivative(1) was found to exhibit blue fluorescence in gaseous state or in methanol and yellow fluorescence in solid state. The N-alkylation of imidazole subunit(s) in 1 using n-propyl iodide generated unsymmetrically or symmetrically alkylated thiazolothiazolebridged imidazolium salts with good water solubility and remarkably strong emission in solution. Furthermore, the replacement of iodide counter-anion by triflate or bis(trifluoromethane sulfonyl)imide achieved remarkably strong emission in solid state and in solution as well as good water solubility. The strong fluorescence of dicationic salts with triflate and NTf_(2)^(-)counter-anions in solid state can be ascribed to their twisted and rigid structures induced by interionic C-H···F hydrogen bonding.
文摘A simple method for the synthesis of new bithienylethenes bearing a functional group on the cyclopentene moi- ety is developed. Three new photochromic compounds （4a, 4b, 4c） have been successfully synthesized through this simple method, and exhibit good photochromic properties with alternate irradiation of ultraviolet and visible light. Furthermore, the fluorescence of compound 4a, which bears a quinoline unit on the cyclopentene, can be modulated via optic and proton dual inputs. Upon excitation by 320 nm light, 4a emits a strong fluorescence at 404 nm. After irradiation with 254 nm light, the emission intensity is reduced due to the fluorescence resonance energy transfers （FRET） from quinoline unit to bithienylethene unit. Moreover, on addition of H~, the fluorescence is quenched completely due to the protonation of the quinoline. In addition, both the FRET and protonation process are reversi- ble, which indicates a potential application in molecular switches and logic gates.
基金supported by the National Natural Science Foundation of China(21535004,91753111,21575081,21775091,21705098)the Key Research and Development Program of Shandong Province(2018YFJH0502)+1 种基金the Natural Science Foundation of Shandong Province(ZR201702200428)the Project of Shandong Province Higher Educational Science and Technology Program(J17KA116)
文摘Au-Se bond strategy has been applied to construct fluorescence nanoprobe that is being used to simultaneously dual-image the tumor markers matrix metalloproteinase-2(MMP-2)and matrix metalloproteinase-7(MMP-7)in vitro.The two Se-terminating ligand peptide chains respectively labeled with fluorescein isothiocyanate(FITC)and 5-Carboxytetramethylrhodamine(5-TAMRA)dyes are attached to the surface of Au nanoparticles(NPs).The nanoprobe can be specifically cut off by MMP-2 and MMP-7 respectively to carry out significant enhanced fluorescence recovery for simultaneously imaging both markers.The nanoprobe not only displays high selectivity and sensitivity towards MMP-2 and MMP-7,but also has strong anti-interference stability against biothiols and enhanced fidelity for avoiding"false positive"results.This approach offers new perspectives in designing tumor-related early diagnosis approaches and also provides strategies for clinical applications.
