A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition...A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.展开更多
A simply synthesized 4-aminonaphthalimide derivative 1 expresses both polarity and viscosity sensitive fluorescence spectra,indicating its potential usage as an environmentally sensitive fluorescence probe. By compari...A simply synthesized 4-aminonaphthalimide derivative 1 expresses both polarity and viscosity sensitive fluorescence spectra,indicating its potential usage as an environmentally sensitive fluorescence probe. By comparing the fluorescence behavior of 1 with that of a known 4-aminonaphthalimide derivative 2,it was found that the substitution of the 4-amino group has profound influence on the environmentally sensitive fluorescence properties of 4-aminonaphthalimide.展开更多
A novel fluorescent probe 9-（4-（1,2-diamine）benzene-N1-phenyl）acridine（DABPA） was synthesized for the detection of nitric oxide（NO） and characterized by IR, 1H-NMR and EI-MS spectroscopy. Based on a photoelect...A novel fluorescent probe 9-（4-（1,2-diamine）benzene-N1-phenyl）acridine（DABPA） was synthesized for the detection of nitric oxide（NO） and characterized by IR, 1H-NMR and EI-MS spectroscopy. Based on a photoelectron transfer mechanism, the fl uorescence intensities of DABPA were investigated with the different concentrations of NO. Under the optimal experimental conditions, the fl uorescence intensity of DABPA had a good linear relationship（R2=0.9977） with NO concentration in the range from 1×10-7 to 1.5×10-6 mol/L with a detection limit of 1×10-8 mol/L. The cytotoxicity induced by DABPA was evaluated by the MTT（3-（4,5-dimethylthiazol-2-yl）-2,5diphenyl tetrazolium bromide） assay for biological application. Furthermore, the probe DABPA had also been successfully applied to real-time image NO produced in PC12 cells in the presence of L-arginine.展开更多
Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximu...Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximum was blue shifted with the polymerization progress. Inthe period of auto-acceleration of the polymerization the enhancement of fluorescence intensityand blue shift of peak wavelength in spectra could be observed evidently. This means that thesolvatochromic properties of PNP are influenced not only by the solvent polarity but also by theviscosity of the medium (especially by the phase transitiott). In solid state PNP emits from thecharge transfer excited state without solvent relaxation. The transient emission spectra and theresults from Bakhshiev model of solvent relaxation coincide with that from the polymerizationexperiment.展开更多
The upregulation of 4-hydroxyphenylpyruvate dioxygenase(HPPD)can protect plants from adverse abiotic stress.Therefore,studying the changes of HPPD under abiotic stress is extremely valuable.In this study,we employed a...The upregulation of 4-hydroxyphenylpyruvate dioxygenase(HPPD)can protect plants from adverse abiotic stress.Therefore,studying the changes of HPPD under abiotic stress is extremely valuable.In this study,we employed a rational molecular design strategy to prepare an HPPD-responsive fluorescent probe consisting of a pyrene fluorophore,a linker and a benquitrione skeleton recognition moiety that functions via an aggregation–disaggregation sensing mechanism.As predicted,this probe exhibited an obvious turn-on fluorescence response towards HPPD.In addition,in vivo imaging demonstrated the excellent capability of this probe to track HPPD in Arabidopsis thaliana,and the dynamic changes in HPPD were monitored under different stress degrees of high temperature and Cadmium(II)ion(Cd^(2+))stress.This work provides an efficient design strategy for acquiring a noninvasive HPPD fluorescence probe,which could evaluate the degree of stress and be further employed for exploring the stress resistance mechanism in plants.展开更多
With the decrease of pH value from 8.45 to -1.0, the UV-Vis absorption and fluorescent spectra of 1,2-bis（4-pyridyl） ethylene（BPE） took on the same changing trend at four different successive pH stages： 8.45--7.2...With the decrease of pH value from 8.45 to -1.0, the UV-Vis absorption and fluorescent spectra of 1,2-bis（4-pyridyl） ethylene（BPE） took on the same changing trend at four different successive pH stages： 8.45--7.20, 7.20--5.62, 5.62--2.60, and 2.60--1.0, namely, no change, decrease, increase, and decrease again. Among these, in a range of 7.20--5.62, the fluorescence wavelength blueshifted from 418 to 359 nm, but the UV-Vis absorption wavelength, in contrast, redshifted from 285 to 298 nm. The fluorescence intensity of BPE had a drop even to quench upon a decline in the pH value from 2.60 to -1.0 probably owing to its cation-re interaction to reduce the π electron cloud density of BPE. Two dissociation constants, pKa1（4.30±0.01） and PKa2（5.65±0.04）, were obtained based on fluorescence data. The changes of fluorescence spectra indicate that BPE has ＂oft-on-off＂ switch behavior. The fluorescent spectra of BPE were nearly independent on the presence of α- and β-cyclodextrins.展开更多
A pH-sensor with a pKa value of 5.05 based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene（BODIPY） dye was synthesized and demonstrated to be highly sensitive within a pH range of 4.0--6.0 and was highly photostable, ...A pH-sensor with a pKa value of 5.05 based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene（BODIPY） dye was synthesized and demonstrated to be highly sensitive within a pH range of 4.0--6.0 and was highly photostable, which makes it a potential pH fluorescent probe. The new pH-sensor will find its application in studying acidic organelles in living cells.展开更多
基金supported by the National Natural Science Foundation of China(21804050)the National Key R and D Program of China(2018YFD0901003)+2 种基金the Science and Technology Planning Project of Xiamen,China(3502Z20183031)the Fujian Provincial Fund Project(2018J01432)the Xiamen Science and Technology Planning Project,China(3502Z20183031)。
文摘A ratiometric fluorescent probe for hypoxanthine(Hx)detection was established based on the mimic enzyme and fluorescence characteristics of cobalt-doped graphite-phase carbon nitride(Co doped g-C_(3)N_(4)).In addition to emitting strong fluorescence,the peroxidase activity of Co doped g-C_(3)N_(4)can catalyze the reaction of O-phenylenediamine and H_(2)O_(2)to produce diallyl phthalate which can emit yellow fluorescence at 570 nm.Through the decomposition of Hx by xanthine oxidase,Hx can be indirectly detected by the generating hydrogen peroxide based on the measurement of fluorescent ratio I(F_(570)/F_(370)).The linear range was 1.7-272.2 mg/kg(R^(2)=0.997),and the detection limit was 1.52 mg/kg(3σ/K,n=9).The established method was applied to Hx detection in bass,grass carp,and shrimp,and the data were verified by HPLC.The result shows that the established probe is sensitive,accurate,and reliable,and can be used for Hx detection in aquatic products.
基金the National Science & Technology Pillar Program of China(No.2011BAE31B01)
文摘A simply synthesized 4-aminonaphthalimide derivative 1 expresses both polarity and viscosity sensitive fluorescence spectra,indicating its potential usage as an environmentally sensitive fluorescence probe. By comparing the fluorescence behavior of 1 with that of a known 4-aminonaphthalimide derivative 2,it was found that the substitution of the 4-amino group has profound influence on the environmentally sensitive fluorescence properties of 4-aminonaphthalimide.
基金Funded by the National Natural Science Foundation of China(Nos.50802069,81100890,51272191)the Fundamental Research Funds for the Central Unversities(WUT:2013-IV-010)the Students Innovation and Entrepreneurship Training Program of WHUT(20141049701012)
文摘A novel fluorescent probe 9-（4-（1,2-diamine）benzene-N1-phenyl）acridine（DABPA） was synthesized for the detection of nitric oxide（NO） and characterized by IR, 1H-NMR and EI-MS spectroscopy. Based on a photoelectron transfer mechanism, the fl uorescence intensities of DABPA were investigated with the different concentrations of NO. Under the optimal experimental conditions, the fl uorescence intensity of DABPA had a good linear relationship（R2=0.9977） with NO concentration in the range from 1×10-7 to 1.5×10-6 mol/L with a detection limit of 1×10-8 mol/L. The cytotoxicity induced by DABPA was evaluated by the MTT（3-（4,5-dimethylthiazol-2-yl）-2,5diphenyl tetrazolium bromide） assay for biological application. Furthermore, the probe DABPA had also been successfully applied to real-time image NO produced in PC12 cells in the presence of L-arginine.
基金This project was supported by the National Natural Science Foundation of China
文摘Fluorescence properties of 1-pheny1-3-(4'-nitrophenyl) pyrazoline (PNP) were studied inbulk polymerization process of methylmethacrylate (MMA). The fluorescence intensity of PNPwas enhanced and the emission maximum was blue shifted with the polymerization progress. Inthe period of auto-acceleration of the polymerization the enhancement of fluorescence intensityand blue shift of peak wavelength in spectra could be observed evidently. This means that thesolvatochromic properties of PNP are influenced not only by the solvent polarity but also by theviscosity of the medium (especially by the phase transitiott). In solid state PNP emits from thecharge transfer excited state without solvent relaxation. The transient emission spectra and theresults from Bakhshiev model of solvent relaxation coincide with that from the polymerizationexperiment.
基金supported by the National Key R&D Program of China(No.2021YFD1700103)National Natural Science Foundation of China(21837001,21676113,21772054,22007035)+1 种基金the 111 Project B17019,the Scholar support program of CCNU(0900–31101090002)Hubei Province Natural Science Foundation(No.2020CFB487).
文摘The upregulation of 4-hydroxyphenylpyruvate dioxygenase(HPPD)can protect plants from adverse abiotic stress.Therefore,studying the changes of HPPD under abiotic stress is extremely valuable.In this study,we employed a rational molecular design strategy to prepare an HPPD-responsive fluorescent probe consisting of a pyrene fluorophore,a linker and a benquitrione skeleton recognition moiety that functions via an aggregation–disaggregation sensing mechanism.As predicted,this probe exhibited an obvious turn-on fluorescence response towards HPPD.In addition,in vivo imaging demonstrated the excellent capability of this probe to track HPPD in Arabidopsis thaliana,and the dynamic changes in HPPD were monitored under different stress degrees of high temperature and Cadmium(II)ion(Cd^(2+))stress.This work provides an efficient design strategy for acquiring a noninvasive HPPD fluorescence probe,which could evaluate the degree of stress and be further employed for exploring the stress resistance mechanism in plants.
基金Supported by the National Natural Science Foundation of China(No.20675009)
文摘With the decrease of pH value from 8.45 to -1.0, the UV-Vis absorption and fluorescent spectra of 1,2-bis（4-pyridyl） ethylene（BPE） took on the same changing trend at four different successive pH stages： 8.45--7.20, 7.20--5.62, 5.62--2.60, and 2.60--1.0, namely, no change, decrease, increase, and decrease again. Among these, in a range of 7.20--5.62, the fluorescence wavelength blueshifted from 418 to 359 nm, but the UV-Vis absorption wavelength, in contrast, redshifted from 285 to 298 nm. The fluorescence intensity of BPE had a drop even to quench upon a decline in the pH value from 2.60 to -1.0 probably owing to its cation-re interaction to reduce the π electron cloud density of BPE. Two dissociation constants, pKa1（4.30±0.01） and PKa2（5.65±0.04）, were obtained based on fluorescence data. The changes of fluorescence spectra indicate that BPE has ＂oft-on-off＂ switch behavior. The fluorescent spectra of BPE were nearly independent on the presence of α- and β-cyclodextrins.
基金Supported by the State Basic Research Project of China(No.2002CB713808)
文摘A pH-sensor with a pKa value of 5.05 based on 4,4-difluoro-4-bora-3a,4a-diaza-s-indacene（BODIPY） dye was synthesized and demonstrated to be highly sensitive within a pH range of 4.0--6.0 and was highly photostable, which makes it a potential pH fluorescent probe. The new pH-sensor will find its application in studying acidic organelles in living cells.
