A novel, rapid and simple CdTe quantum dots （QDs） based technology platform was established for selective and sensitive determination of vitamin B6 in aqueous solution. It can perform accurate and reproducible quant...A novel, rapid and simple CdTe quantum dots （QDs） based technology platform was established for selective and sensitive determination of vitamin B6 in aqueous solution. It can perform accurate and reproducible quantification of vitamin B6 in pharmaceutical with satisfactory results.展开更多
In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nan...In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nanosheets into MoS2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect（IFE）.Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO2 nanosheets.Under the optimum conditions,the limit of detection（LOD） of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples（n = 3）.Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.展开更多
In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduce...In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduced electron transfer(PET)effect.Two perylene diimide isomers PDI-P and PDI-B were designed and synthesized,and their molecular structures were characterized by high-resolution Fourier transform mass spectrometry(HRMS),nuclear magnetic resonance hydrogen and carbon spectroscopy(~1H and~(13)C NMR).The interaction between ionizing radiation and fluorescent molecules was simulated by HCl titration.The results show that combining PDIs and HCl can improve fluorescence through the retro-PET process.Despite the similarities in chemical structures,the fluorescent enhancement multiple of PDI-B with aromatic amine as electron donor is much higher than that of PDI-P with alkyl amine.In the direct irradiation experiments of ionizing radiation,the emission enhancement multiples of PDI-P and PDI-B are 2.01 and 45.4,respectively.Furthermore,density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations indicate that the HOMO and HOMO-1 energy ranges of PDI-P and PDI-B are 0.54 e V and 1.13 e V,respectively.A wider energy range has a stronger driving force on electrons,which is conducive to fluorescence quenching.Both femtosecond transient absorption spectroscopy(fs-TAS)and transient fluorescence spectroscopy(TFS)tests show that PDI-B has shorter charge separation lifetime and higher electron transfer rate constant.Although both isomers can significantly reduce LOD during PET process,PDI-B with aromatic amine has a wider detection range of 0.118—240 Gy due to its larger emission enhancement,which is a leap of three orders of magnitude.It breaks through the detection range of gamma radiation reported in existing studies,and provides theoretical support for the further study of sensitive and effective new materials for ionizing radiation detection.展开更多
A sensitive and selective zinc ion ratiometric fluorescence sensor has been synthesized and characterized. This material displays dual fluorescence. After the material was bonded to a closed-shell metal ion, such as ...A sensitive and selective zinc ion ratiometric fluorescence sensor has been synthesized and characterized. This material displays dual fluorescence. After the material was bonded to a closed-shell metal ion, such as Zn2＋, the recovery of the local excited fluorescence of the material-Zn2＋ complex, largely at the expense of the intramolecular charge transfer fluorescence, is consistent with the difference between selected orbital transitions of the free dye and the metal-chelated complex. For instance, the contribution of the πtpy→πtpy, transition becomes more prominent. This is also consistent with the results of the fluorescence decay behavior, measured via a time-correlated single photon counting setup. In contrast, the corresponding open shell Ni2＋ -bound complex quenches both kinds of photoluminescence, due to spin-orbit coupling.展开更多
Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensiona...Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensional COF nanosheets(COF NS)by ultrasound treatment.Gold nanoparticles(Au NPs)were loaded with COF NS to prepare AuNPs/COF NS(Au@COF NS).Secondly,rhodamine B(RhB)modified substrate peptide(Pep)for chymosin was linked with Au@COF NS to construct a Pep-Au@COF NS nanocomposite.For the sensing principle,fluorescence of RhB was quenched by Au@COF NS and the fluorescence intensity was weak due to the fluorescence resonance energy transfer between COF NS and RhB of Pep.However,in the presence of chymosin,the RhB was released by specific cleavage of the substrate peptide by chymosin and resulted in the recovery of fluorescence.The increased fluorescence intensity was proportional to the increase of chymosin concentration and thus a“turn on”fluorescent sensor for chymosin was constructed.The sensor showed a linear range in the concentration of 0.05-60.00μg/mL for the detection of chymosin with a detection limit of 20 ng/mL.The sensor was used to quantify chymosin in rennet product with good selectivity,which has the potential applications in cheese manufacturing.展开更多
A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn2+. Its fluorescence quantum yield increas...A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn2+. Its fluorescence quantum yield increase more than one order of magnitude and a red shift could be noticed when passing from the apolar to the polar solvent.展开更多
Bacillus anthracis is an extremely dangerous bacterium that causes high morbidity and mortality.Developing a simple and effective sensor to detect its unique biomarker 2,6-pyridine dicarboxylic acid(DPA)is urgently re...Bacillus anthracis is an extremely dangerous bacterium that causes high morbidity and mortality.Developing a simple and effective sensor to detect its unique biomarker 2,6-pyridine dicarboxylic acid(DPA)is urgently required to prevent anthrax infection.In this work,a ratiometric fluorescence sensor based on lanthanide-metal-organic frameworks(MOFs)was developed for the sensitive and selective recognition of DPA.展开更多
Ensuring food safety remains a global challenge because of the presence of foodborne pathogens,such as Escherichia coli and Staphylococcus aureus.In this study,we present a turn-on fluorescence biosensor based on an i...Ensuring food safety remains a global challenge because of the presence of foodborne pathogens,such as Escherichia coli and Staphylococcus aureus.In this study,we present a turn-on fluorescence biosensor based on an iron metal-organic framework(Fe-MOF)for the selective and rapid detection of two major foodborne pathogens,E.coli and S.aureus.Fe-MOF was synthesised via a solvothermal method and thoroughly characterised by Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDX),and thermogravimetric analysis(TGA).Upon interaction with bacterial suspensions,the sensor exhibited significant fluorescence enhancement,which was attributed to electron transfer modulation triggered by bacterial surface components.The analytical performance was evaluated across three matrices—phosphate-buffered saline(PBS),drinking water,and milk—achieving detection limits as low as 0.464 log CFU/mL for S.aureus and 0.584 log CFU/mL for E.coli.The sensor enabled rapid detection within less than 1 h with high recovery rates(95-104%)across all tested matrices,confirming its practical usability for real sample analysis.These findings address a critical gap in biosensor research by validating Fe-MOFs for practical food-safety applications in multiple real-world environments.展开更多
An 8-hydroxyquinolinate-based metal–organic framework[Zn(L)]·2MeOH·H_(2)O(1)was synthesized for the first time by treating a novel 8-hydroxyquinolinate ligand H_(2)L involving two carboxylate groups with zi...An 8-hydroxyquinolinate-based metal–organic framework[Zn(L)]·2MeOH·H_(2)O(1)was synthesized for the first time by treating a novel 8-hydroxyquinolinate ligand H_(2)L involving two carboxylate groups with zinc salt.Based on single-crystal X-ray analysis,the Zn-MOF exhibits a porous framework assembled from interlinked nanotubes that are constructed from three 4_(3)helices.展开更多
Nicotinamide mononucleotide(NMN),valued for its anti-aging potential,is a popular product in health and wellness.Developing a rapid and accurate method for NMN detection would aid in market regulation and oversight.In...Nicotinamide mononucleotide(NMN),valued for its anti-aging potential,is a popular product in health and wellness.Developing a rapid and accurate method for NMN detection would aid in market regulation and oversight.In this work,we developed a ratiometric fluorescence sensor based on a europium-based metal-organic framework(Eu-MOF)for the rapid and convenient detection of NMN.The dual-ligand strategy,utilizing 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine and 2-aminoterephthalic acid as ligands,enables the Eu-MOF to exhibit dual fluorescence emission in the blue and red regions.Upon the addition of Cu2+ions,the blue fluorescence was quenched,and the subsequent introduction of NMN restored the signal,using red fluorescence as a stable internal reference.Under optimal conditions,the sensor demonstrated a linear detection range of 0.005–2 mg mL^(-1) with a response time of 1 min.For NMN detection in actual products,simple dissolution in water was sufficient,achieving a recovery rate ranging from 92.2%to 103.8%,the results were consistent with those obtained via traditional high-performance liquid chromatography.This fluorescence sensor offers a promising tool for quality control,counterfeit detection,and regulatory monitoring of NMN products in the health and wellness industry.展开更多
A Ln^(3+)-doped(Yb^(3+),Tm^(3+)or Yb^(3+),Er^(3+)co-doped)NaYF4 nanoparticle/polystyrene hybrid fibrous membrane(HFM)was fabricated using an electrospinning technique.The HFM shows upconversion luminescence(UCL),flexi...A Ln^(3+)-doped(Yb^(3+),Tm^(3+)or Yb^(3+),Er^(3+)co-doped)NaYF4 nanoparticle/polystyrene hybrid fibrous membrane(HFM)was fabricated using an electrospinning technique.The HFM shows upconversion luminescence(UCL),flexibility,superhydrophobicity and processability.The UCL membrane can be used as a fluorescence sensor to detect bioinformation from a single water droplet(~10μl).Based on the fluorescence resonance energy transfer,the detection limits of this sensor can reach 1 and 10 ppb for the biomolecule,avidin,and the dye molecule,Rhodamine B,respectively,which are superior to most of the fluorescence sensors reported in previous works.After the fluorescence detection,the target droplet was easily removed without residues on the UCL membrane surface due to its superhydrophobic property,which exhibits an excellent recyclability that cannot be achieved by traditional liquid-based detection systems.展开更多
An“on–off–on”fluorescence sensor was designed for rapidly and consecutively detecting 4-nitrophenol and cerium(IV)without the use of any labeling materials.The yellow carbon dots were synthesized by a simple one-s...An“on–off–on”fluorescence sensor was designed for rapidly and consecutively detecting 4-nitrophenol and cerium(IV)without the use of any labeling materials.The yellow carbon dots were synthesized by a simple one-step hydrothermal approach,and various techniques were applied to investigate the morphology,structure,and optical properties of the carbon dots.Under the optimal experimental conditions,4-nitrophenol rapidly quenched the fluorescence of carbon dots as a result of the inner filter eff ect(IFE).The fluorescence intensity of carbon dots was linear with the concentration of 4-nitrophenol(1–150μmol/L)and the limit of detection was 0.32μmol/L.The fluorescence was gradually recovered as the cerium(IV)concentration(0.5–100μmol/L)increased in CDs/4-NP,and the limit of detection was 0.16μmol/L.The sensor showed good selectivity and demonstrated high accuracy for the analysis of 4-nitrophenol and cerium(IV)in actual water samples.展开更多
In this study,a simple and effective ratiometric fluorescence method has been developed for carbaryl detection,utilizing red emissive carbon dots(R-CDs).The underlying principle of this proposed strategy relies on the...In this study,a simple and effective ratiometric fluorescence method has been developed for carbaryl detection,utilizing red emissive carbon dots(R-CDs).The underlying principle of this proposed strategy relies on the rapid hydrolysis of carbaryl under an alkaline condition and production of 1-naphthol with blue-emission at 462 nm.Furthermore,the as-synthesized R-CDs(Em.677 nm),serve as a reference,enhancing the visual tracking of carbaryl through the transformation of fluorescent color from red to blue.The concentration of carbaryl exhibits a commendable linear correlation with the ratio of fluorescence intensity,ranging from 0 to 20μg/m L(R^(2)=0.9989)with a low detection limit of 0.52 ng/m L.Additionally,the described methodology can be used for the enzyme-free visual assay of carbaryl,even in the presence of other carbamate pesticides and metal ions,in tap water and lake water samples with excellent accuracy(spiked recoveries,94%-106.1%),high precision(relative standard deviation(RSD)≤2.42),and remarkable selectivity.This fast and highly sensitive naked-eye ratiometric sensor holds immense promise for carbaryl detection in intricate environments and food safety fields.展开更多
A novel optical chemical sensor L was designed and synthesized for the determination of silver ions.The sensor L was derived from 1-naphthaldehyde and 3,4,5-tris(hexadecyloxy)benzohydrazide.The sensor L shows high sen...A novel optical chemical sensor L was designed and synthesized for the determination of silver ions.The sensor L was derived from 1-naphthaldehyde and 3,4,5-tris(hexadecyloxy)benzohydrazide.The sensor L shows high sensitivity and selectivity for Ag+detection in comparison to other metal cations(Mg^(2+),Ca^(2+),Al^(3+),Cr^(3+),Fe^(3+),Co^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),Pb^(2+))and has no significant response to other common metal cations.Upon addition of Ag+,the fluorescent emission of the sensor L was enhanced dramatically but other metal cations had no same response.The detection limit for Ag+was 1.2×10^(−7) mol/L.Therefore,the sensor L is useful for Ag+detection with some advantages including sensitivity,selectivity,simplicity and low-cost.展开更多
This study presents a novel boron-difluoride complex-based fluorescent nanofilm sensor capable of detecting sarin vapors in the environment by reporting an output fluorescence signal.The sensor’s evaluation demonstra...This study presents a novel boron-difluoride complex-based fluorescent nanofilm sensor capable of detecting sarin vapors in the environment by reporting an output fluorescence signal.The sensor’s evaluation demonstrated an exceptionally low detection limit for sarin vapor,even in the presence of various interfering gases,with theoretical and practical limits of detection of 0.7 and 1 ppb,respectively.The sensor featured a rapid response time(less than 2 s),a broad linear detection range(1 ppb–1000 ppm),and superior selectivity for sarin vapor over a group of interfering analytes,outperforming existing sarin sensors.Mechanistic study indicates that the sensor’s heightened sensitivity to sarin vapor is due to the robust affinity of nitrogen atoms within the core BODIQ unit for sarin.Additionally,the tetraphenylethylene structure with steric hindrance effectively inhibits the tight packing of BODIQ derivatives,and forms numerous microporous structures in the self-assembled nanofilm,which are beneficial for the mass transfer,enhancing the sensor efficiency in detecting vapors.Furthermore,we have achieved the differentiation of sarin,diethyl chlorophosphate,and HCl vapor through the analysis of sensing kinetic.This fluorescent sensor opens new avenues for sustainable,low-cost,and environment-friendly portable devices,as well as for environmental monitoring and tracking applications.展开更多
Innovative design of sensing fluorophores possessing superior photophysical properties,porosity,and packing-resistance structures is pivotal for high performance film-based fluorescent sensors.Herein,PDCB,a perylene m...Innovative design of sensing fluorophores possessing superior photophysical properties,porosity,and packing-resistance structures is pivotal for high performance film-based fluorescent sensors.Herein,PDCB,a perylene monoimide(PMI)derivative incorporating large spatial phenyl-carborane was synthesized and found to exhibit unexpected photophysical properties.The structurally bent PDCB exhibits not only PMI-like emission but also a red-shifted emission.In sharp contrast,PMI-CBH,a linear PMI derivative,exhibits only PMI-like emission.Furthermore,upon local excitation,PDCB undergoes a photoinduced electron transfer(PET)between PMI and phenylcarborane,resulting in a charge-transfer state.Two other PMI derivatives,PCB and PDCBP,showed a similar phenomenon.The PET rate is in the order of PCB(48 ps^(-1))>PDCB(163 ps^(-1))>PDCBP(815 ps^(-1))in toluene,which decreases with increasing steric hindrance,inferring structure reorganization prior to the PET process.As expected,a fabricated PDCB-based sensor showed excellent performance in acetone sensing.展开更多
A new oxazole compound,1,4 bis(naphtho[1,2 d][1,3]oxazol 2 yl)benzene(BNOB)was synthesized and incorporated into a thin plasticized polymeric membrane for sensing Amrinon.The sensor exhibits a linear response to Amrin...A new oxazole compound,1,4 bis(naphtho[1,2 d][1,3]oxazol 2 yl)benzene(BNOB)was synthesized and incorporated into a thin plasticized polymeric membrane for sensing Amrinon.The sensor exhibits a linear response to Amrinon in the range of 798×10-7—152×10-4 mol/L at pH 328—404.The response mainly originates from the Primary Inner Filter Effect,which causes a decrease in the fluorescence intensity of the sensor membrane.The distinct advantages of the proposed sensor are of full reversibility,high sensitivity and selectivity as well as short response time(<1 min),indicating that the sensor can be used to monitor Amrinon in serum samples.展开更多
In the past decade,people have conducted extensive research on the synthesis and application properties of various functionalized pillararenes.Pillararenes show good application prospects in the field of sensors due t...In the past decade,people have conducted extensive research on the synthesis and application properties of various functionalized pillararenes.Pillararenes show good application prospects in the field of sensors due to the rich host-vip recognition in their rigid electron-rich cavities.However,most reported pillararenes are functionalized by alkoxy modification,which results in poor charge transfer nature and weak fluorescence response.A π-conjugated charge-transfer system P5BN was obtained by introducing electron-donating triarylamine(Ar_(3)N)and electron-deficient triarylborane(Ar_(3)B)into pillar[5]arene skeleton,which significantly improved its luminescence behavior and was further used for fluorescence detection applications.The molecular structure showed that P5BN provided a good macrocyclic cavity to encapsulate amino acids molecules of suitable size.It was found that P5BN,as a fluorescent sensor,showed a highly sensitive and selective response to L-arginine(L-Arg),resulting in a significant enhancement of the fluorescence at 408 nm of P5BN with the lowest detection concentration being 2.21×10^(-8) mol/L.The recognition mechanism was demonstrated through experiments and DFT theoretical calculations.展开更多
Since their discovery by Hugo Schiff in 1864,Schiff bases and their metal complexes have gained recognition for their catalytic and biological properties.These compounds exhibit diverse functionalities,serving as cata...Since their discovery by Hugo Schiff in 1864,Schiff bases and their metal complexes have gained recognition for their catalytic and biological properties.These compounds exhibit diverse functionalities,serving as catalysts in synthetic processes and displaying notable biological activities such as antifungal,antibacterial,anti-malarial,and antiviral effects.In various applications,Schiff bases serve as versatile tools,particularly in sensing appli-cations.Through coordination with various metal ions,they form stable complexes.They are utilized as fluo-rescent turn-on/turn-off sensors for detecting a wide range of analytes.The coordination ability makes them valuable as chemosensor for detecting environmentally and biologically important analytes.This review provides a thorough overview of Schiff base chemosensors designed for the detection of environmental and biological significance including metal cations,anions,and neutral analytes.It is structured into four focused sections.The first section addresses the use of Schiff base chemosensor for the selective detection of various metal cations,including Ca^(2+),Al^(3+),Cr^(3+),Mn^(2+),Fe^(3+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),and Pb^(2+);The second section examines the application of fluorescent Schiff base sensors in detecting diverse anions such as F^(-),CN^(-),I^(-),and HSO_(4)^(-);The third section investigates the use of Schiff base fluorescent probes for accurate pH detection and determination;and the fourth section explores the utilization of Schiff base sensors for detecting environmentally and biolog-ically important neutral analytes,including insecticides,pesticides,and others.Additionally,the Schiff base chemosensors for metal cations and anions section are concluded with a table,summarizing the reviewed fluorescent Schiff base sensors for enhanced clarity.展开更多
基金the National Natural Science Foundation of China (No.20275014)for financially supporting this work.
文摘A novel, rapid and simple CdTe quantum dots （QDs） based technology platform was established for selective and sensitive determination of vitamin B6 in aqueous solution. It can perform accurate and reproducible quantification of vitamin B6 in pharmaceutical with satisfactory results.
基金financially supported by National Nature Science Foundation of China (No. 21475053)
文摘In this work,molybdenum disulfide quantum dots（MoS2 QDs） were firstly prepared by hydrothermal method using sodium molybdate and glutathione as precursors,and applied in ascorbic acid detection.When joining MnO2 nanosheets into MoS2 QDs solution,they produced an obvious fluorescence quenching,which should be due to inner filter effect（IFE）.Meanwhile,the fluorescent probe was formed,Interestingly,we found that this quenching phenomenon disappeared with the addition of ascorbic acid,In other words,the fluorescence gradually restored.This recovery phenomenon is mainly due to the reduction effect of ascorbic acid for MnO2 nanosheets.Under the optimum conditions,the limit of detection（LOD） of 39 nmol/L for ascorbic acid was achieved with a linear range of 0.33-5.00 μmol/L.The repeatability was better than 5.0% for ascorbic acid in both standard and fruit samples（n = 3）.Moreover,the as-fabricated fluorescent sensing system was successfully employed to detect the ascorbic acid levels in hawthorn and jujube with satisfactory results.
基金financial support from the National Natural Science Foundation of China(Grant No.21801016)the Science and Technology on Applied Physical Chemistry Laboratory(Grant No.6142602220304)。
文摘In order to achieve a wider range of ionizing radiations detection,novel fluorescence sensing materials have been developed that utilize the fluorescence enhancement phenomenon caused by the intramolecular photoinduced electron transfer(PET)effect.Two perylene diimide isomers PDI-P and PDI-B were designed and synthesized,and their molecular structures were characterized by high-resolution Fourier transform mass spectrometry(HRMS),nuclear magnetic resonance hydrogen and carbon spectroscopy(~1H and~(13)C NMR).The interaction between ionizing radiation and fluorescent molecules was simulated by HCl titration.The results show that combining PDIs and HCl can improve fluorescence through the retro-PET process.Despite the similarities in chemical structures,the fluorescent enhancement multiple of PDI-B with aromatic amine as electron donor is much higher than that of PDI-P with alkyl amine.In the direct irradiation experiments of ionizing radiation,the emission enhancement multiples of PDI-P and PDI-B are 2.01 and 45.4,respectively.Furthermore,density functional theory(DFT)and time-dependent density functional theory(TDDFT)calculations indicate that the HOMO and HOMO-1 energy ranges of PDI-P and PDI-B are 0.54 e V and 1.13 e V,respectively.A wider energy range has a stronger driving force on electrons,which is conducive to fluorescence quenching.Both femtosecond transient absorption spectroscopy(fs-TAS)and transient fluorescence spectroscopy(TFS)tests show that PDI-B has shorter charge separation lifetime and higher electron transfer rate constant.Although both isomers can significantly reduce LOD during PET process,PDI-B with aromatic amine has a wider detection range of 0.118—240 Gy due to its larger emission enhancement,which is a leap of three orders of magnitude.It breaks through the detection range of gamma radiation reported in existing studies,and provides theoretical support for the further study of sensitive and effective new materials for ionizing radiation detection.
基金Supported by the National Natural Science Foundation of China(Nos20633070, 20833008)the National Key Basic Research Special Foundation of China(Nos2007CB815202)
文摘A sensitive and selective zinc ion ratiometric fluorescence sensor has been synthesized and characterized. This material displays dual fluorescence. After the material was bonded to a closed-shell metal ion, such as Zn2＋, the recovery of the local excited fluorescence of the material-Zn2＋ complex, largely at the expense of the intramolecular charge transfer fluorescence, is consistent with the difference between selected orbital transitions of the free dye and the metal-chelated complex. For instance, the contribution of the πtpy→πtpy, transition becomes more prominent. This is also consistent with the results of the fluorescence decay behavior, measured via a time-correlated single photon counting setup. In contrast, the corresponding open shell Ni2＋ -bound complex quenches both kinds of photoluminescence, due to spin-orbit coupling.
基金supported by Major Science and Technology Project of Yunnan Province(202302AE090022)Key Research and Development Program of Yunnan(202203AC100010)+4 种基金the National Natural Science Foundation of China(32160597,32160236,32371463)National Key Research and Development Program of China(2022YFC2601604)Cardiovascular Ultrasound Innovation Team of Yunnan Province(202305AS350021)Spring City Plan:the High-Level Talent Promotion and Training Project of Kunming(2022SCP001)Graduate Tutor Team of Yunnan Province,and the Second Phase of"Double-First Class"Program Construction of Yunnan University.
文摘Chymosin is one of the critical enzymes in cheese making.Herein,we proposed a novel fluorometric assay for chymosin determination.Firstly,covalent organic frameworks(COF)were synthesized and exfoliated to 2-dimensional COF nanosheets(COF NS)by ultrasound treatment.Gold nanoparticles(Au NPs)were loaded with COF NS to prepare AuNPs/COF NS(Au@COF NS).Secondly,rhodamine B(RhB)modified substrate peptide(Pep)for chymosin was linked with Au@COF NS to construct a Pep-Au@COF NS nanocomposite.For the sensing principle,fluorescence of RhB was quenched by Au@COF NS and the fluorescence intensity was weak due to the fluorescence resonance energy transfer between COF NS and RhB of Pep.However,in the presence of chymosin,the RhB was released by specific cleavage of the substrate peptide by chymosin and resulted in the recovery of fluorescence.The increased fluorescence intensity was proportional to the increase of chymosin concentration and thus a“turn on”fluorescent sensor for chymosin was constructed.The sensor showed a linear range in the concentration of 0.05-60.00μg/mL for the detection of chymosin with a detection limit of 20 ng/mL.The sensor was used to quantify chymosin in rennet product with good selectivity,which has the potential applications in cheese manufacturing.
文摘A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn2+. Its fluorescence quantum yield increase more than one order of magnitude and a red shift could be noticed when passing from the apolar to the polar solvent.
基金the Natural Science Foundation of Shaanxi Province，the Special Foundation of the Education Department of Shaanxi Province，the Special Research Fund of Xianyang Normal University for Talent Introduction
基金supported by the Natural Science Foundation of Jilin Province(20220101082JC).
文摘Bacillus anthracis is an extremely dangerous bacterium that causes high morbidity and mortality.Developing a simple and effective sensor to detect its unique biomarker 2,6-pyridine dicarboxylic acid(DPA)is urgently required to prevent anthrax infection.In this work,a ratiometric fluorescence sensor based on lanthanide-metal-organic frameworks(MOFs)was developed for the sensitive and selective recognition of DPA.
文摘Ensuring food safety remains a global challenge because of the presence of foodborne pathogens,such as Escherichia coli and Staphylococcus aureus.In this study,we present a turn-on fluorescence biosensor based on an iron metal-organic framework(Fe-MOF)for the selective and rapid detection of two major foodborne pathogens,E.coli and S.aureus.Fe-MOF was synthesised via a solvothermal method and thoroughly characterised by Fourier-transform infrared spectroscopy(FTIR),X-ray diffraction(XRD),scanning electron microscopy with energy-dispersive X-ray spectroscopy(SEM-EDX),and thermogravimetric analysis(TGA).Upon interaction with bacterial suspensions,the sensor exhibited significant fluorescence enhancement,which was attributed to electron transfer modulation triggered by bacterial surface components.The analytical performance was evaluated across three matrices—phosphate-buffered saline(PBS),drinking water,and milk—achieving detection limits as low as 0.464 log CFU/mL for S.aureus and 0.584 log CFU/mL for E.coli.The sensor enabled rapid detection within less than 1 h with high recovery rates(95-104%)across all tested matrices,confirming its practical usability for real sample analysis.These findings address a critical gap in biosensor research by validating Fe-MOFs for practical food-safety applications in multiple real-world environments.
基金supported by the National Natural Science Foundation of China(Grants 21671002 and 21603001)Anhui Province Natural Science Funds for Distinguished Young Scholar(Grants 1808085J25)the Provincial Natural Science Research Program of Higher Education Institutions of Anhui Province(KJ2019A0071).
文摘An 8-hydroxyquinolinate-based metal–organic framework[Zn(L)]·2MeOH·H_(2)O(1)was synthesized for the first time by treating a novel 8-hydroxyquinolinate ligand H_(2)L involving two carboxylate groups with zinc salt.Based on single-crystal X-ray analysis,the Zn-MOF exhibits a porous framework assembled from interlinked nanotubes that are constructed from three 4_(3)helices.
基金supported by the National Key Research and Devel-opment Program of China(2022YFF1100803)the Science and Technology Plan of Market Regulatory Administration of Jiangsu Province(KJ2024070).
文摘Nicotinamide mononucleotide(NMN),valued for its anti-aging potential,is a popular product in health and wellness.Developing a rapid and accurate method for NMN detection would aid in market regulation and oversight.In this work,we developed a ratiometric fluorescence sensor based on a europium-based metal-organic framework(Eu-MOF)for the rapid and convenient detection of NMN.The dual-ligand strategy,utilizing 2,4,6-tris(4-carboxyphenyl)-1,3,5-triazine and 2-aminoterephthalic acid as ligands,enables the Eu-MOF to exhibit dual fluorescence emission in the blue and red regions.Upon the addition of Cu2+ions,the blue fluorescence was quenched,and the subsequent introduction of NMN restored the signal,using red fluorescence as a stable internal reference.Under optimal conditions,the sensor demonstrated a linear detection range of 0.005–2 mg mL^(-1) with a response time of 1 min.For NMN detection in actual products,simple dissolution in water was sufficient,achieving a recovery rate ranging from 92.2%to 103.8%,the results were consistent with those obtained via traditional high-performance liquid chromatography.This fluorescence sensor offers a promising tool for quality control,counterfeit detection,and regulatory monitoring of NMN products in the health and wellness industry.
基金supported by the National Natural Science Foundation of China(Grant Nos.51402038,11474046 and 11274057)the Program for New Century Excellent Talents in University(NCET-13-0702)+5 种基金the Technology Foundation for Selected Overseas Chinese Scholars from the Ministry of Personnel of China,the Scientific Research Foundation for Doctors of Liaoning Province(Grant No.20141118)the Educational Committee Foundation of Liaoning Province(Grant No.L2014547)the Science and Technology Project of Liaoning Province(Grant No.2012222009)the Program for Liaoning Excellent Talents in University(LNET)(Grant No.LR2015016)the Science and Technique Foundation of Dalian(Grant Nos.2014J11JH134 and 2015J12JH201)the Fundamental Research Funds for Central Universities(Grant Nos.DC201502080203 and DC201502080304).
文摘A Ln^(3+)-doped(Yb^(3+),Tm^(3+)or Yb^(3+),Er^(3+)co-doped)NaYF4 nanoparticle/polystyrene hybrid fibrous membrane(HFM)was fabricated using an electrospinning technique.The HFM shows upconversion luminescence(UCL),flexibility,superhydrophobicity and processability.The UCL membrane can be used as a fluorescence sensor to detect bioinformation from a single water droplet(~10μl).Based on the fluorescence resonance energy transfer,the detection limits of this sensor can reach 1 and 10 ppb for the biomolecule,avidin,and the dye molecule,Rhodamine B,respectively,which are superior to most of the fluorescence sensors reported in previous works.After the fluorescence detection,the target droplet was easily removed without residues on the UCL membrane surface due to its superhydrophobic property,which exhibits an excellent recyclability that cannot be achieved by traditional liquid-based detection systems.
基金National Natural Science Foundation of China(22274096 and 22272119)the Shanghai Municipal Science and Technology Major Project(2021SHZDZX0100)+2 种基金the Science and Technology Committee of Shanghai Municipality(2022-4-ZD-03)the Shanghai Pilot Program for Basic Researchthe Fundamental Research Funds for the Central Universities。
文摘An“on–off–on”fluorescence sensor was designed for rapidly and consecutively detecting 4-nitrophenol and cerium(IV)without the use of any labeling materials.The yellow carbon dots were synthesized by a simple one-step hydrothermal approach,and various techniques were applied to investigate the morphology,structure,and optical properties of the carbon dots.Under the optimal experimental conditions,4-nitrophenol rapidly quenched the fluorescence of carbon dots as a result of the inner filter eff ect(IFE).The fluorescence intensity of carbon dots was linear with the concentration of 4-nitrophenol(1–150μmol/L)and the limit of detection was 0.32μmol/L.The fluorescence was gradually recovered as the cerium(IV)concentration(0.5–100μmol/L)increased in CDs/4-NP,and the limit of detection was 0.16μmol/L.The sensor showed good selectivity and demonstrated high accuracy for the analysis of 4-nitrophenol and cerium(IV)in actual water samples.
基金supported by the Natural Science Foundation of the Science and Technology Department of Jilin Province(No.20220101086JC)。
文摘In this study,a simple and effective ratiometric fluorescence method has been developed for carbaryl detection,utilizing red emissive carbon dots(R-CDs).The underlying principle of this proposed strategy relies on the rapid hydrolysis of carbaryl under an alkaline condition and production of 1-naphthol with blue-emission at 462 nm.Furthermore,the as-synthesized R-CDs(Em.677 nm),serve as a reference,enhancing the visual tracking of carbaryl through the transformation of fluorescent color from red to blue.The concentration of carbaryl exhibits a commendable linear correlation with the ratio of fluorescence intensity,ranging from 0 to 20μg/m L(R^(2)=0.9989)with a low detection limit of 0.52 ng/m L.Additionally,the described methodology can be used for the enzyme-free visual assay of carbaryl,even in the presence of other carbamate pesticides and metal ions,in tap water and lake water samples with excellent accuracy(spiked recoveries,94%-106.1%),high precision(relative standard deviation(RSD)≤2.42),and remarkable selectivity.This fast and highly sensitive naked-eye ratiometric sensor holds immense promise for carbaryl detection in intricate environments and food safety fields.
基金This work was supported by the National Natural Science Foundation of China(Nos.21064006,21262032 and 21161018)the Program for Changjiang Scholars and Innovative Research Team in University of Ministry of Education of China(No.IRT1177)+2 种基金the Natural Science Foundation of Gansu Province(No.1010RJZA018)the Youth Foundation of Gansu Province(No.2011GS04735)NWNU-LKQN-11-32.
文摘A novel optical chemical sensor L was designed and synthesized for the determination of silver ions.The sensor L was derived from 1-naphthaldehyde and 3,4,5-tris(hexadecyloxy)benzohydrazide.The sensor L shows high sensitivity and selectivity for Ag+detection in comparison to other metal cations(Mg^(2+),Ca^(2+),Al^(3+),Cr^(3+),Fe^(3+),Co^(2+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),Pb^(2+))and has no significant response to other common metal cations.Upon addition of Ag+,the fluorescent emission of the sensor L was enhanced dramatically but other metal cations had no same response.The detection limit for Ag+was 1.2×10^(−7) mol/L.Therefore,the sensor L is useful for Ag+detection with some advantages including sensitivity,selectivity,simplicity and low-cost.
基金National Key Research and Development Program of China,Grant/Award Number:2022YFA12055001National Natural Science Foundation of China,Grant/Award Numbers:22202128,21972084,21820102005+4 种基金Scientific Research Plan of Shaanxi Province of China,Grant/Award Number:2021TD-18Innovative Research Team in University,Grant/Award Number:IRT-14R33Program of Introducing Talents of Discipline to Universities,Grant/Award Number:B14041Shaanxi Fundamental Science Research Project for Chemistry and Biology,Grant/Award Number:23JHQ074Fundamental Research Funds for the Central Universities,Grant/Award Numbers:GK202003040,GK202205016。
文摘This study presents a novel boron-difluoride complex-based fluorescent nanofilm sensor capable of detecting sarin vapors in the environment by reporting an output fluorescence signal.The sensor’s evaluation demonstrated an exceptionally low detection limit for sarin vapor,even in the presence of various interfering gases,with theoretical and practical limits of detection of 0.7 and 1 ppb,respectively.The sensor featured a rapid response time(less than 2 s),a broad linear detection range(1 ppb–1000 ppm),and superior selectivity for sarin vapor over a group of interfering analytes,outperforming existing sarin sensors.Mechanistic study indicates that the sensor’s heightened sensitivity to sarin vapor is due to the robust affinity of nitrogen atoms within the core BODIQ unit for sarin.Additionally,the tetraphenylethylene structure with steric hindrance effectively inhibits the tight packing of BODIQ derivatives,and forms numerous microporous structures in the self-assembled nanofilm,which are beneficial for the mass transfer,enhancing the sensor efficiency in detecting vapors.Furthermore,we have achieved the differentiation of sarin,diethyl chlorophosphate,and HCl vapor through the analysis of sensing kinetic.This fluorescent sensor opens new avenues for sustainable,low-cost,and environment-friendly portable devices,as well as for environmental monitoring and tracking applications.
基金the Ministry of Science and Technology of China(grant nos.SQ2022YFA1200081 and 2022010133)the National Natural Science Foundation of China(grant nos.21820102005 and 22132002)111 project(grant no.B14041).
文摘Innovative design of sensing fluorophores possessing superior photophysical properties,porosity,and packing-resistance structures is pivotal for high performance film-based fluorescent sensors.Herein,PDCB,a perylene monoimide(PMI)derivative incorporating large spatial phenyl-carborane was synthesized and found to exhibit unexpected photophysical properties.The structurally bent PDCB exhibits not only PMI-like emission but also a red-shifted emission.In sharp contrast,PMI-CBH,a linear PMI derivative,exhibits only PMI-like emission.Furthermore,upon local excitation,PDCB undergoes a photoinduced electron transfer(PET)between PMI and phenylcarborane,resulting in a charge-transfer state.Two other PMI derivatives,PCB and PDCBP,showed a similar phenomenon.The PET rate is in the order of PCB(48 ps^(-1))>PDCB(163 ps^(-1))>PDCBP(815 ps^(-1))in toluene,which decreases with increasing steric hindrance,inferring structure reorganization prior to the PET process.As expected,a fabricated PDCB-based sensor showed excellent performance in acetone sensing.
文摘A new oxazole compound,1,4 bis(naphtho[1,2 d][1,3]oxazol 2 yl)benzene(BNOB)was synthesized and incorporated into a thin plasticized polymeric membrane for sensing Amrinon.The sensor exhibits a linear response to Amrinon in the range of 798×10-7—152×10-4 mol/L at pH 328—404.The response mainly originates from the Primary Inner Filter Effect,which causes a decrease in the fluorescence intensity of the sensor membrane.The distinct advantages of the proposed sensor are of full reversibility,high sensitivity and selectivity as well as short response time(<1 min),indicating that the sensor can be used to monitor Amrinon in serum samples.
文摘In the past decade,people have conducted extensive research on the synthesis and application properties of various functionalized pillararenes.Pillararenes show good application prospects in the field of sensors due to the rich host-vip recognition in their rigid electron-rich cavities.However,most reported pillararenes are functionalized by alkoxy modification,which results in poor charge transfer nature and weak fluorescence response.A π-conjugated charge-transfer system P5BN was obtained by introducing electron-donating triarylamine(Ar_(3)N)and electron-deficient triarylborane(Ar_(3)B)into pillar[5]arene skeleton,which significantly improved its luminescence behavior and was further used for fluorescence detection applications.The molecular structure showed that P5BN provided a good macrocyclic cavity to encapsulate amino acids molecules of suitable size.It was found that P5BN,as a fluorescent sensor,showed a highly sensitive and selective response to L-arginine(L-Arg),resulting in a significant enhancement of the fluorescence at 408 nm of P5BN with the lowest detection concentration being 2.21×10^(-8) mol/L.The recognition mechanism was demonstrated through experiments and DFT theoretical calculations.
文摘Since their discovery by Hugo Schiff in 1864,Schiff bases and their metal complexes have gained recognition for their catalytic and biological properties.These compounds exhibit diverse functionalities,serving as catalysts in synthetic processes and displaying notable biological activities such as antifungal,antibacterial,anti-malarial,and antiviral effects.In various applications,Schiff bases serve as versatile tools,particularly in sensing appli-cations.Through coordination with various metal ions,they form stable complexes.They are utilized as fluo-rescent turn-on/turn-off sensors for detecting a wide range of analytes.The coordination ability makes them valuable as chemosensor for detecting environmentally and biologically important analytes.This review provides a thorough overview of Schiff base chemosensors designed for the detection of environmental and biological significance including metal cations,anions,and neutral analytes.It is structured into four focused sections.The first section addresses the use of Schiff base chemosensor for the selective detection of various metal cations,including Ca^(2+),Al^(3+),Cr^(3+),Mn^(2+),Fe^(3+),Ni^(2+),Cu^(2+),Zn^(2+),Cd^(2+),Hg^(2+),and Pb^(2+);The second section examines the application of fluorescent Schiff base sensors in detecting diverse anions such as F^(-),CN^(-),I^(-),and HSO_(4)^(-);The third section investigates the use of Schiff base fluorescent probes for accurate pH detection and determination;and the fourth section explores the utilization of Schiff base sensors for detecting environmentally and biolog-ically important neutral analytes,including insecticides,pesticides,and others.Additionally,the Schiff base chemosensors for metal cations and anions section are concluded with a table,summarizing the reviewed fluorescent Schiff base sensors for enhanced clarity.
