Hydrophilic rare-earth up-conversion nanophosphors(UCNPs)with small sizes and a strong up-conversion luminescence have attracted much interest.Herein the simultaneous control of morphologies and the up-conversion lumi...Hydrophilic rare-earth up-conversion nanophosphors(UCNPs)with small sizes and a strong up-conversion luminescence have attracted much interest.Herein the simultaneous control of morphologies and the up-conversion luminescence intensities was reported for NaYF_(4)∶Yb/Er nanophosphors by a facile hydrothermal procedure with different surfactants.With the change of the surfactants from polyvinylpyrrolidone(PVP)to sodium citrate(CIT),edetate disodium(EDTA)or sodium dodecyl benzenesulfonate(SDBS),the morphology of NaYF_(4)∶Yb/Er nanophosphors transformed from nanoparticles with a diameter of about 70.0 nm to hexagonal nanoblocks with a thickness of about 125.0 nm and a length of about 240.0 nm,nanorods with a diameter of about 700.0 nm and a length of about 2.6μm,or nanowires with a diameter of 250.0 nm and a length of about 3.2μm.Simultaneously,their up-conversion luminescence intensity went down gradually under laser irradiation at a wavelength of 980 nm due to the increase of photobleaching.PVP-capped NaYF_(4)∶Yb/Er nanoparticles exhibited the smallest size and the strongest up-conversion luminescence intensity.Biological experiment results revealed that NaYF_(4)∶Yb/Er nanophosphors exhibited a high biocompatibility and could be used as biological labels with a perfect signal-to-noise ratio for cancer cell imaging.展开更多
Carbon quantum dots(CQDs) exhibit tremendous advantages for plant growth study due to its strong fluorescence and good biocompatibility. The fluorescent CQDs were synthesized by the onestep microwave method with the r...Carbon quantum dots(CQDs) exhibit tremendous advantages for plant growth study due to its strong fluorescence and good biocompatibility. The fluorescent CQDs were synthesized by the onestep microwave method with the raw materials of citric acid(CA) and urea(UR), and expressed a unique green fluorescence with the optimal excitation wavelength of over 400 nm through adjusting the doping of N elements. It is demonstrated that CQDs can act as deliver media in plant and fluorescent probes for plant cell imaging through directly cultivated in the seedlings of melon and wheat, respectively. Based on the effects of the fluorescent CQDs on plants growth, we can further study the mechanisms of the ions transport in plants.展开更多
As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent sensors.However,the CDs with deep-red(DR)or near-infrared(NIR)emis...As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent sensors.However,the CDs with deep-red(DR)or near-infrared(NIR)emission have rarely been reported.In this work,we prepared deep-red emissive fluorine-doped carbon quantum dots(F-CDs)by introducing a precursor simultaneously containing fluorine and amidogen.The synergistic effect of nitrogen doping and D-π-A pattern production contributed to the maximum emission of F-CDs at 636 nm with an absolute quantum yield of 36.00%±0.68%.Moreover,we designed an F-CDs-based fluorescence assay to determine the content of hypochlorite(ClO^(-)),with a limit of detection(LOD)as low as 15.4 nmol/L,indicating the high sensitivity of F-CDs to ClO^(-).In real samples,the F-CDs-based fluorescent sensor exhibited excellent sensitivity and selectivity in the detection of ClO^(-),with an error below 2%,suggesting their great potential in daily life.In cancer cell imaging,the F-CDs not only demonstrated high sensitivity to ClO^(-)but also exhibited excellent mitochondria targeting,as evidenced by the high Pearson's correlation coefficient(PCC)of 0.93 in colocalization analysis.The work presented here suggests the great potential of replacing commercial dyes with F-CDs for highly specific mitochondria labeling and cell imaging.展开更多
Natural plants and Chinese herbal medicines are valuable resources.It is one of the new tasks for medical workers to study the new application fields of these resources.In this work,one kind of traditional Chinese her...Natural plants and Chinese herbal medicines are valuable resources.It is one of the new tasks for medical workers to study the new application fields of these resources.In this work,one kind of traditional Chinese herbal plant,Alisma,was chosen as a carbon source to synthesize the carbon dots(CDs).This kind of CDs has an amorphous carbon structure and shows strong stability to time,temperature,and ion strength.The results show that the degradation efficiency of malachite green dye can reach 100%in 4.5 h without illumination,and the degradation efficiency is better than that in dark environment.In addition,the CDs have also been successfully applied to HeLa cell imaging.Simple synthesis method,stable properties,good photodegradation and bioimaging applications make this material of great application value.展开更多
By introducing a naphthothiadiazole(NT)unit as the main building block,a non-doped and red emissive conjugated polymer poly(9,9-dihexylfluorene-alt-naphthothiadiazole)(PFNT)is readily obtained through a two-step synth...By introducing a naphthothiadiazole(NT)unit as the main building block,a non-doped and red emissive conjugated polymer poly(9,9-dihexylfluorene-alt-naphthothiadiazole)(PFNT)is readily obtained through a two-step synthesis.Since the NT unit has a large twist angle with its neighboring segment,the aggregation-induced quenching(AIQ)effect of PFNT can be effectively suppressed in the condensed state.As a result,the corresponding PFNT polymer dot(Pdot)exhibits a high fluorescence quantum yield of53.2%with peak emission at 616 nm,which is one of the most efficient red Pdots known.PFNT Pdot shows good biocompatibility and can be employed for living cell fluorescent imaging with high brightness.It also can be used for specific subcellular organelle imaging through immunofluorescence labeling.Furthermore,the PFNT Pdot demonstrates much better photostability for long-time cell fluorescence imaging than commercial red dyes.The high performances of PFNT Pdot make it a promising fluorescent probe for practical bioapplications.展开更多
Integrating discrete plasmonic nanoparticles into assemblies can induce plasmonic coupling that produces collective plasmonic properties,which are not available for single nanoparticles.Theoretical analysis revealed t...Integrating discrete plasmonic nanoparticles into assemblies can induce plasmonic coupling that produces collective plasmonic properties,which are not available for single nanoparticles.Theoretical analysis revealed that plasmonic coupling derived from assemblies could produce stronger electromagnetic field enhancement effects.Thus,plasmonic assemblies enable better performance in plasmon-based applications,such as enhanced fluorescence and Raman effects.This makes them hold great potential for trace analyte detection and nanomedicine.Herein,we focus on the recent advances in various plasmonic nanoassembles such as dimers,tetramers,and core-satellite structures,and discuss their applications in biosensing and cell imaging.The fabrication strategies for self-assembled plasmonic nanostructures are described,including top-down strategies,self-assembly methods linked by DNA,ligand,polymer,amino acid,or proteins,and chemical overgrowth methods.Thereafter,their applications in biosensor and cell imaging based on dark-field imaging,surface-enhanced Raman scattering,plasmonic circular dichroism,and fluorescence imaging are discussed.Finally,the remaining challenges and prospects are elucidated.展开更多
Excitation wavelength dependent(Ex-De) luminescent materials have attracted intense attention due to their great potential in multicolor bioimaging,dynamic anti-counterfeiting,and light emitting devices.However,it rem...Excitation wavelength dependent(Ex-De) luminescent materials have attracted intense attention due to their great potential in multicolor bioimaging,dynamic anti-counterfeiting,and light emitting devices.However,it remains a formidable challenge to construct an Ex-De luminescent biomaterial with green starting materials,excellent biocompatibility,good water solubility,and multiple color emission for dynamic cell imaging.In this work,nanocomposites based on the facile self-assembly strategy of bovine serum albumin(BSA) and Au(Ⅰ)-complex are rationally designed and synthesized to simultaneously present Ex-De fluorescence(429–516 nm) and decent phosphorescence(~615 nm) in a dilute aqueous solution.Combinatory analyses of spectroscopic and microscopic results reveal that the luminescent mechanism of Au(Ⅰ)-BSA nanocomposites is cluster-induced Ex-De fluorescence and metal-to-ligand charge transition(MLCT) based phosphorescence.Importantly,based on the excellent biocompatibility,water-solubility and color-tunable emission over the entire visible region(360–800 nm),the Au(Ⅰ)-BSA nanocomposites are successfully used for cell imaging with multiple and switchable colors on demand.What is more,the solid tablets of Au(Ⅰ)-BSA nanoparticles showed pressure-responsive luminescence and decent room temperature phosphorescence.This work provides an assembling-induced emission strategy for the design of water-soluble,non-cytotoxic,and color-tunable luminescent biomaterials based on the composite of protein and Au nanoparticles.展开更多
Two new ratiometric hypoxia probes(Ir-C343 and Ir-GFP)are synthesized by covalently incorporating florescent internal standard molecules coumarin 343(C343)and green fluorescent protein(GFP)into bis[1-(9,9-dimethyl-9H-...Two new ratiometric hypoxia probes(Ir-C343 and Ir-GFP)are synthesized by covalently incorporating florescent internal standard molecules coumarin 343(C343)and green fluorescent protein(GFP)into bis[1-(9,9-dimethyl-9H-fluoren-2-yl)-isoquinoline](succinylacetone)Ir(Ⅲ)(Ir-fliq),respectively.After connecting with internal standard molecules,the Ir-fliq moiety still exhibits high sensitivity to oxygen concentration,while the fluorescence intensity of the internal standard remains relatively constant under different oxygen concentrations.As a result,a ratiometric response is realized that is only related to oxygen concentration.In addition,Ir-GFP shows more promising applications in the ratiometric hypoxia imaging of cells due to its long excitation wavelength,good water solubility,high biocompatibility,and low relative fluorescence intensity compared with the phosphorescent emitter Ir-fliq.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
Atomic force microscopy(AFM)is one of the effective methods for imaging the morphological and physical properties of living cells in a near-physiological environment.However,several problems caused by the adhesion of ...Atomic force microscopy(AFM)is one of the effective methods for imaging the morphological and physical properties of living cells in a near-physiological environment.However,several problems caused by the adhesion of living cells and extension of the cell membranes seriously affect the image quality during living cell imaging,hindering the study of living cells.In this work,jumping mode AFM imaging was used to image living cells at varied probe lifting heights to meet image quality requirements,and image quality related to the probe lifting height is discussed in detail.The jumping mode was divided into three parts based on the varying heights of the lifted probe,namely near-contact mode,half-jumping mode,and full-jumping mode,and the causes of their imaging drawbacks were analyzed.At an appropriate lifting height,the probe can be completely free from the influence of cell adhesion and self-excited oscillation,thus avoiding the occurrence of“trail”phenomena and invalid points in the imaging of living cells and improving the image quality.Additionally,this work provides a new approach to calculating the lateral force through the adhesion of trace and retrace scanning at a low height,which is important for studying the extension characteristics of the cell membrane.展开更多
Dear Editor,CRISPR-Cas9 (clustered regularly interspaced short palin- dromic repeats-CRISPR associated) systems have been harnessed for kinds of genome manipulation, including gene editing, transcription regulation,...Dear Editor,CRISPR-Cas9 (clustered regularly interspaced short palin- dromic repeats-CRISPR associated) systems have been harnessed for kinds of genome manipulation, including gene editing, transcription regulation, and chromosome loci imaging (Dominguez et al., 2016; Komor et al., 2017). A typical engineered CRISPR-Cas9 system is composed of a Cas9 protein and a single guide RNA (sgRNA), which could form a protein/RNA complex to recognize and cleave DNA sequence (Hsu et al., 2014; Wright et al., 2016).展开更多
Niobium carbide MXene quantum dots(Nb2 C MQDs)derived from 2 D Nb2 CTx(MXene)are the rising-star material recently.Herein,a sulfur and nitrogen co-doped Nb2 C MQDs(S,N-MQDs)were synthesized through a hydrothermal meth...Niobium carbide MXene quantum dots(Nb2 C MQDs)derived from 2 D Nb2 CTx(MXene)are the rising-star material recently.Herein,a sulfur and nitrogen co-doped Nb2 C MQDs(S,N-MQDs)were synthesized through a hydrothermal method.The obtained Nb2 C MQDs have excellent green fluorescence with a quantum yield(QY)of 17.25%.In addition,they exhibited excitatio n-dependent photoluminescence,antiphotobleaching and dispersion stability.They emit light at 520 nm when excited at 390 nm.The Nb2 C MQDs could be successfully applied to copper ion detection with detection limit of 2μmol/L and Caco-2 cells imaging.展开更多
β-Cyclodextrin (β-CD) and its derivatives functionalized magnetic nanoparticles (MNPs) with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydr...β-Cyclodextrin (β-CD) and its derivatives functionalized magnetic nanoparticles (MNPs) with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydroxy- propyl/sulfobutyl ether-β-CD-MNPs (CM/HP/SBE-β-CD-MNPs) nanocomposites were characterized by the TEM, FTIR, DLS, Zeta potential, XRD and VSM. In addition, the loading and release performance of the as-prepared nanocarriers for the hydrophobic anti-cancer drug curcumin was also investigated. The results revealed that the SBE-fl-CD-MNPs possessed the highest loading and release capacity in comparison with other two nanosystems. Cellular uptake and imaging suggested that the SBE-β-CD-MNPs entered into the cell, and curcumin could be suc-cessfully delivered into the cell by SBE-β-CD-MNPs nanocarrier. Moreover, cell toxicity experiments demonstrated the SBE-β-CD-MNPs were non-toxic, while curcumin loaded SBE-β-CD-MNPs showed high potential to kill the HepG2 cells. The as-prepared magnetic composites were expected to expand their potential applications in bio- medical field.展开更多
A simple assay for the detection of Fe^3+ in water by means of fluorescence spectroscopy was developed based on a commercially available reagent, Azomethine-H(A-H), allowing sensing trace levels of Fe^3+ with high...A simple assay for the detection of Fe^3+ in water by means of fluorescence spectroscopy was developed based on a commercially available reagent, Azomethine-H(A-H), allowing sensing trace levels of Fe^3+ with high selectivity over other cations. A significant fluorescence quenching of A-H at 424 nm was found after its binding with Fe^3+ in 100% aqueous solution at pH=7.0, while other physiologically relevant metal ions posed little interference. The fluorescence responses can be well described by the modified Stern-Volmer equation. A good linear relationship(Re=0.9904) was observed up to 1.6x10 5 mol/L Fe^3+ ions. The detection limit, calculated via the 3tr IUPAC(international union of pure and applied chemistry) criteria, was 1.95x10-7 mol/L. Moreover, the colorimetric and fluorescent response of A-H to Fe^3+ can be conveniently detected by the naked eye, providing a facile method for visual detection of Fe^3+. The proposed method was used to determine Fe^3+ in water samples. Moreover, inverted fluorescence microscopy imaging using human umbilical vein endothelial cells shows that A-H can be used as an effective fluorescent probe for detecting Fe^3+ in living cells.展开更多
A new rhodamine B derivative T1 has been rationally synthesized and displayed selective Pd(Ⅱ)-amplified absorbance and fluorescence emission above 540 nm in methanol-water. Upon the addition of Pd(Ⅱ), the spirol...A new rhodamine B derivative T1 has been rationally synthesized and displayed selective Pd(Ⅱ)-amplified absorbance and fluorescence emission above 540 nm in methanol-water. Upon the addition of Pd(Ⅱ), the spirolactam ring was unfolded and a 1:1 metal-ligand complex formed, which can be used for ''naked-eyes" detection. In addition, fluorescence imaging experiments of Pd^(2+) in HepG2 living cells showed its valuable application in biological systems.展开更多
We demonstrate a deep-learning-based fiber imaging system that can transfer real-time artifact-free cell images through a meter-long Anderson localizing optical fiber.The cell samples are illuminated by an incoherent ...We demonstrate a deep-learning-based fiber imaging system that can transfer real-time artifact-free cell images through a meter-long Anderson localizing optical fiber.The cell samples are illuminated by an incoherent LED light source.A deep convolutional neural network is applied to the image reconstruction process.The network training uses data generated by a setup with straight fiber at room temperature(∼20°C)but can be utilized directly for high-fidelity reconstruction of cell images that are transported through fiber with a few degrees bend or fiber with segments heated up to 50°C.In addition,cell images located several millimeters away from the bare fiber end can be transported and recovered successfully without the assistance of distal optics.We provide evidence that the trained neural network is able to transfer its learning to recover images of cells featuring very different morphologies and classes that are never“seen”during the training process.展开更多
Six binuclear rare earth compounds were synthesized through the ligand of 4-Bromo-N-hydroxy-Nmethyl-benzamide(sH_2 bha). Compounds 1-3 are isomorphous, and compound 1 is crystallized in the monoclinic system with th...Six binuclear rare earth compounds were synthesized through the ligand of 4-Bromo-N-hydroxy-Nmethyl-benzamide(sH_2 bha). Compounds 1-3 are isomorphous, and compound 1 is crystallized in the monoclinic system with the P2_1/c space group. Compounds 4 and 5 are isomorphous, and compound 4 is crystallized in the triclinic system with the P-1 space group. Compound 6 is crystallized in the triclinic system with the P-1 space group. The compounds were characterized by thermogravimetric analysis(TGA) and IR spectroscopy. The fluorescence spectrum in the visible area shows characteristic peaks of Eu, Tb, and Dy compounds. The efficiency of Eu compound on the viability of PC3 cells was assessed using CCK8 assays. From the CCK8 results, ionic concentration may have a great effect on PC3 cells' proliferation. Eu compound shows red fluorescence in the cytoplasm of PC3 cell. As for Eu compound, it might have potential application in cell imaging technology.展开更多
High fluorescence quantum yield(QY),excellent fluorescence stability,and low toxicity are essential for a good cellular imaging fluorescent probe.Green-emissive carbon quantum dots(CQDs)with many advantages,such as un...High fluorescence quantum yield(QY),excellent fluorescence stability,and low toxicity are essential for a good cellular imaging fluorescent probe.Green-emissive carbon quantum dots(CQDs)with many advantages,such as unique fluorescence properties,anti-photobleaching,low toxicity,fine biocompatibility and high penetration depth in tissues,have been considered as a potential candidate in cell imaging fluorescent probes.Herein,N,S-codoped green-emissive CQDs(QY=64.03%)were synthesized by the one-step hydrothermal method,with m-phenylenediamine as the carbon and nitrogen source,and L-cysteine as the nitrogen and sulfur dopant,under the optimum condition of 200℃ reaction for 2 h.Their luminescence was found to originate from the surface state.In light of the satisfactory photobleaching resistance and the low cytotoxicity,CQDs were used as a cell imaging probe for HeLa cell imaging.The results clearly indicate that cells can be labeled with CQDs,which can not only enter the cytoplasm,but also enter the nucleus through the nuclear pore,showing their broad application prospect in the field of cell imaging.展开更多
Cells are the basic structural and functional units of organisms.Dynamic analysis and manipulation of specific components in living cells would provide valuable information for the study of related biological processe...Cells are the basic structural and functional units of organisms.Dynamic analysis and manipulation of specific components in living cells would provide valuable information for the study of related biological processes.Advances in fluorescence microscopy have allowed real-time monitoring of biological events at the molecular level.Meanwhile,the development of highperformance fluorescence probes has become a critical issue.Functional nucleic acids(FNAs)are oligonucleotides with special chemical and biological functions,and aptamers with excellent molecular recognition capability are one of the most important representatives.They have attracted extensive attention in the field of live-cell study,owing to intrinsic advantages of simple synthesis,convenient modification,low immunogenicity and high programmability.This review focuses on recent research progress in fluorescence imaging and manipulation of cells using FNAs,particularly aptamers,as the molecular tools.Finally,a summary is provided and the related challenges are discussed.展开更多
In this study, we report a novel and facile autoclave strategy for synthesis of near-infrared (NIR) CulnS2 QDs by employing glutathione (GSH) as capping ligand and stabilizer in aqueous media under 100 ~C. Various...In this study, we report a novel and facile autoclave strategy for synthesis of near-infrared (NIR) CulnS2 QDs by employing glutathione (GSH) as capping ligand and stabilizer in aqueous media under 100 ~C. Various experi- mental parameters including the ratio of precursors, reaction time, reaction temperature, pH effect and stability have been systematically studied. The QDs were characterized by X-ray diffraction (XRD), transmission electron micro- scope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The as-synthesized NIR QDs exhibited low cytotoxicity and maintained excellent cell viability even up to 100 gg/mL. After bioconjugation with Arg-Gly-Asp (RGD) peptide, the obtained CulnS2-RGD QDs have demonstrated high targeting ability with good fluorescence cell imaging performance.展开更多
基金Shanghai Academic Research Leader,China(No.20XD1420200)Shanghai Shuguang Program,China(No.18SG29)。
文摘Hydrophilic rare-earth up-conversion nanophosphors(UCNPs)with small sizes and a strong up-conversion luminescence have attracted much interest.Herein the simultaneous control of morphologies and the up-conversion luminescence intensities was reported for NaYF_(4)∶Yb/Er nanophosphors by a facile hydrothermal procedure with different surfactants.With the change of the surfactants from polyvinylpyrrolidone(PVP)to sodium citrate(CIT),edetate disodium(EDTA)or sodium dodecyl benzenesulfonate(SDBS),the morphology of NaYF_(4)∶Yb/Er nanophosphors transformed from nanoparticles with a diameter of about 70.0 nm to hexagonal nanoblocks with a thickness of about 125.0 nm and a length of about 240.0 nm,nanorods with a diameter of about 700.0 nm and a length of about 2.6μm,or nanowires with a diameter of 250.0 nm and a length of about 3.2μm.Simultaneously,their up-conversion luminescence intensity went down gradually under laser irradiation at a wavelength of 980 nm due to the increase of photobleaching.PVP-capped NaYF_(4)∶Yb/Er nanoparticles exhibited the smallest size and the strongest up-conversion luminescence intensity.Biological experiment results revealed that NaYF_(4)∶Yb/Er nanophosphors exhibited a high biocompatibility and could be used as biological labels with a perfect signal-to-noise ratio for cancer cell imaging.
基金Funded by the National Natural Science Foundation of China(Nos.61575150 and 61377092)the Fundamental Research Funds for the Central Universities(WUT:2017II46GX)
文摘Carbon quantum dots(CQDs) exhibit tremendous advantages for plant growth study due to its strong fluorescence and good biocompatibility. The fluorescent CQDs were synthesized by the onestep microwave method with the raw materials of citric acid(CA) and urea(UR), and expressed a unique green fluorescence with the optimal excitation wavelength of over 400 nm through adjusting the doping of N elements. It is demonstrated that CQDs can act as deliver media in plant and fluorescent probes for plant cell imaging through directly cultivated in the seedlings of melon and wheat, respectively. Based on the effects of the fluorescent CQDs on plants growth, we can further study the mechanisms of the ions transport in plants.
基金supported by the National Natural Science Foundation of China(Nos.82222035 and 81602489)the Guangdong Basic and Applied Basic Research Foundation(Nos.2021A1515111036 and 2022A1515110308)+1 种基金the Medical Scientific Research Foundation of Guangdong Province of China(No.A2023274)the Basic Research Program of Shenzhen Innovation Council(No.JCYJ20210324105609024)。
文摘As a type of new carbon-based nanomaterials,carbon dots(CDs)possess exceptional optical properties,making them highly desirable for use in fluorescent sensors.However,the CDs with deep-red(DR)or near-infrared(NIR)emission have rarely been reported.In this work,we prepared deep-red emissive fluorine-doped carbon quantum dots(F-CDs)by introducing a precursor simultaneously containing fluorine and amidogen.The synergistic effect of nitrogen doping and D-π-A pattern production contributed to the maximum emission of F-CDs at 636 nm with an absolute quantum yield of 36.00%±0.68%.Moreover,we designed an F-CDs-based fluorescence assay to determine the content of hypochlorite(ClO^(-)),with a limit of detection(LOD)as low as 15.4 nmol/L,indicating the high sensitivity of F-CDs to ClO^(-).In real samples,the F-CDs-based fluorescent sensor exhibited excellent sensitivity and selectivity in the detection of ClO^(-),with an error below 2%,suggesting their great potential in daily life.In cancer cell imaging,the F-CDs not only demonstrated high sensitivity to ClO^(-)but also exhibited excellent mitochondria targeting,as evidenced by the high Pearson's correlation coefficient(PCC)of 0.93 in colocalization analysis.The work presented here suggests the great potential of replacing commercial dyes with F-CDs for highly specific mitochondria labeling and cell imaging.
基金National Natural Science Foundation of China(No.U1860112).
文摘Natural plants and Chinese herbal medicines are valuable resources.It is one of the new tasks for medical workers to study the new application fields of these resources.In this work,one kind of traditional Chinese herbal plant,Alisma,was chosen as a carbon source to synthesize the carbon dots(CDs).This kind of CDs has an amorphous carbon structure and shows strong stability to time,temperature,and ion strength.The results show that the degradation efficiency of malachite green dye can reach 100%in 4.5 h without illumination,and the degradation efficiency is better than that in dark environment.In addition,the CDs have also been successfully applied to HeLa cell imaging.Simple synthesis method,stable properties,good photodegradation and bioimaging applications make this material of great application value.
基金the support of the Hundred Talents Program of Sun Yat-sen University(No.76190-18841211)Hebei DHRSS Research Fund,China(No.E2019100005)the Highlevel Talents Research Star-up Project of Hebei University(No.521000981336)。
文摘By introducing a naphthothiadiazole(NT)unit as the main building block,a non-doped and red emissive conjugated polymer poly(9,9-dihexylfluorene-alt-naphthothiadiazole)(PFNT)is readily obtained through a two-step synthesis.Since the NT unit has a large twist angle with its neighboring segment,the aggregation-induced quenching(AIQ)effect of PFNT can be effectively suppressed in the condensed state.As a result,the corresponding PFNT polymer dot(Pdot)exhibits a high fluorescence quantum yield of53.2%with peak emission at 616 nm,which is one of the most efficient red Pdots known.PFNT Pdot shows good biocompatibility and can be employed for living cell fluorescent imaging with high brightness.It also can be used for specific subcellular organelle imaging through immunofluorescence labeling.Furthermore,the PFNT Pdot demonstrates much better photostability for long-time cell fluorescence imaging than commercial red dyes.The high performances of PFNT Pdot make it a promising fluorescent probe for practical bioapplications.
基金supported by grants from the National Natural Science Foundation of China(Nos.22022412,22274076,21874155)the Primary Research&Development Plan of Jiangsu Province(No.BE2022793)。
文摘Integrating discrete plasmonic nanoparticles into assemblies can induce plasmonic coupling that produces collective plasmonic properties,which are not available for single nanoparticles.Theoretical analysis revealed that plasmonic coupling derived from assemblies could produce stronger electromagnetic field enhancement effects.Thus,plasmonic assemblies enable better performance in plasmon-based applications,such as enhanced fluorescence and Raman effects.This makes them hold great potential for trace analyte detection and nanomedicine.Herein,we focus on the recent advances in various plasmonic nanoassembles such as dimers,tetramers,and core-satellite structures,and discuss their applications in biosensing and cell imaging.The fabrication strategies for self-assembled plasmonic nanostructures are described,including top-down strategies,self-assembly methods linked by DNA,ligand,polymer,amino acid,or proteins,and chemical overgrowth methods.Thereafter,their applications in biosensor and cell imaging based on dark-field imaging,surface-enhanced Raman scattering,plasmonic circular dichroism,and fluorescence imaging are discussed.Finally,the remaining challenges and prospects are elucidated.
基金supported by the National Natural Science Foundation of China(22101208,22125803,22020102006)the Fundamental Research Funds for the Central Universitiesthe Program for Professors of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning。
文摘Excitation wavelength dependent(Ex-De) luminescent materials have attracted intense attention due to their great potential in multicolor bioimaging,dynamic anti-counterfeiting,and light emitting devices.However,it remains a formidable challenge to construct an Ex-De luminescent biomaterial with green starting materials,excellent biocompatibility,good water solubility,and multiple color emission for dynamic cell imaging.In this work,nanocomposites based on the facile self-assembly strategy of bovine serum albumin(BSA) and Au(Ⅰ)-complex are rationally designed and synthesized to simultaneously present Ex-De fluorescence(429–516 nm) and decent phosphorescence(~615 nm) in a dilute aqueous solution.Combinatory analyses of spectroscopic and microscopic results reveal that the luminescent mechanism of Au(Ⅰ)-BSA nanocomposites is cluster-induced Ex-De fluorescence and metal-to-ligand charge transition(MLCT) based phosphorescence.Importantly,based on the excellent biocompatibility,water-solubility and color-tunable emission over the entire visible region(360–800 nm),the Au(Ⅰ)-BSA nanocomposites are successfully used for cell imaging with multiple and switchable colors on demand.What is more,the solid tablets of Au(Ⅰ)-BSA nanoparticles showed pressure-responsive luminescence and decent room temperature phosphorescence.This work provides an assembling-induced emission strategy for the design of water-soluble,non-cytotoxic,and color-tunable luminescent biomaterials based on the composite of protein and Au nanoparticles.
基金financially supported by the National Key R&D Program of China(Nos.2017YFA0701301 and 2017YFA0205400)the National Natural Science Foundation of China(Nos.92163214,51690153,21720102005 and 51803089)the Natural Science Foundation of Jiangsu Province(No.BK20202002)。
文摘Two new ratiometric hypoxia probes(Ir-C343 and Ir-GFP)are synthesized by covalently incorporating florescent internal standard molecules coumarin 343(C343)and green fluorescent protein(GFP)into bis[1-(9,9-dimethyl-9H-fluoren-2-yl)-isoquinoline](succinylacetone)Ir(Ⅲ)(Ir-fliq),respectively.After connecting with internal standard molecules,the Ir-fliq moiety still exhibits high sensitivity to oxygen concentration,while the fluorescence intensity of the internal standard remains relatively constant under different oxygen concentrations.As a result,a ratiometric response is realized that is only related to oxygen concentration.In addition,Ir-GFP shows more promising applications in the ratiometric hypoxia imaging of cells due to its long excitation wavelength,good water solubility,high biocompatibility,and low relative fluorescence intensity compared with the phosphorescent emitter Ir-fliq.
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.
基金This work was supported by National Key R&D Program of China(No.2017YFE0112100)EU H2020 Program(MNR4SCELL No.734174)+1 种基金Jilin Provincial Science and Technology Program(Nos.20180414002GH,20180414081GH,20180520203JH,and 20190702002GH)“111”Project of China(D17017).
文摘Atomic force microscopy(AFM)is one of the effective methods for imaging the morphological and physical properties of living cells in a near-physiological environment.However,several problems caused by the adhesion of living cells and extension of the cell membranes seriously affect the image quality during living cell imaging,hindering the study of living cells.In this work,jumping mode AFM imaging was used to image living cells at varied probe lifting heights to meet image quality requirements,and image quality related to the probe lifting height is discussed in detail.The jumping mode was divided into three parts based on the varying heights of the lifted probe,namely near-contact mode,half-jumping mode,and full-jumping mode,and the causes of their imaging drawbacks were analyzed.At an appropriate lifting height,the probe can be completely free from the influence of cell adhesion and self-excited oscillation,thus avoiding the occurrence of“trail”phenomena and invalid points in the imaging of living cells and improving the image quality.Additionally,this work provides a new approach to calculating the lateral force through the adhesion of trace and retrace scanning at a low height,which is important for studying the extension characteristics of the cell membrane.
文摘Dear Editor,CRISPR-Cas9 (clustered regularly interspaced short palin- dromic repeats-CRISPR associated) systems have been harnessed for kinds of genome manipulation, including gene editing, transcription regulation, and chromosome loci imaging (Dominguez et al., 2016; Komor et al., 2017). A typical engineered CRISPR-Cas9 system is composed of a Cas9 protein and a single guide RNA (sgRNA), which could form a protein/RNA complex to recognize and cleave DNA sequence (Hsu et al., 2014; Wright et al., 2016).
基金the National Nature Science Foundation of China(No.31340014)the Youth Development Project of Medical Technologyin Army(No.13QNP166)+1 种基金the Key Research and Development Program of Science and Technology Department of Sichuan Province(No.2019YFS0514)Funds for the Construction of Master’s Degree Granting Units in Guangxi Zhuang Autonomous Region in 2020 for the support。
文摘Niobium carbide MXene quantum dots(Nb2 C MQDs)derived from 2 D Nb2 CTx(MXene)are the rising-star material recently.Herein,a sulfur and nitrogen co-doped Nb2 C MQDs(S,N-MQDs)were synthesized through a hydrothermal method.The obtained Nb2 C MQDs have excellent green fluorescence with a quantum yield(QY)of 17.25%.In addition,they exhibited excitatio n-dependent photoluminescence,antiphotobleaching and dispersion stability.They emit light at 520 nm when excited at 390 nm.The Nb2 C MQDs could be successfully applied to copper ion detection with detection limit of 2μmol/L and Caco-2 cells imaging.
文摘β-Cyclodextrin (β-CD) and its derivatives functionalized magnetic nanoparticles (MNPs) with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydroxy- propyl/sulfobutyl ether-β-CD-MNPs (CM/HP/SBE-β-CD-MNPs) nanocomposites were characterized by the TEM, FTIR, DLS, Zeta potential, XRD and VSM. In addition, the loading and release performance of the as-prepared nanocarriers for the hydrophobic anti-cancer drug curcumin was also investigated. The results revealed that the SBE-fl-CD-MNPs possessed the highest loading and release capacity in comparison with other two nanosystems. Cellular uptake and imaging suggested that the SBE-β-CD-MNPs entered into the cell, and curcumin could be suc-cessfully delivered into the cell by SBE-β-CD-MNPs nanocarrier. Moreover, cell toxicity experiments demonstrated the SBE-β-CD-MNPs were non-toxic, while curcumin loaded SBE-β-CD-MNPs showed high potential to kill the HepG2 cells. The as-prepared magnetic composites were expected to expand their potential applications in bio- medical field.
基金Supported by the Project of the Shanxi Scholarship Council, China(No.2011-008), the Natural Science Foundation of Shanxi Province, China(No.2013011040-6) and the Project Sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, Ministry of Education, China.
文摘A simple assay for the detection of Fe^3+ in water by means of fluorescence spectroscopy was developed based on a commercially available reagent, Azomethine-H(A-H), allowing sensing trace levels of Fe^3+ with high selectivity over other cations. A significant fluorescence quenching of A-H at 424 nm was found after its binding with Fe^3+ in 100% aqueous solution at pH=7.0, while other physiologically relevant metal ions posed little interference. The fluorescence responses can be well described by the modified Stern-Volmer equation. A good linear relationship(Re=0.9904) was observed up to 1.6x10 5 mol/L Fe^3+ ions. The detection limit, calculated via the 3tr IUPAC(international union of pure and applied chemistry) criteria, was 1.95x10-7 mol/L. Moreover, the colorimetric and fluorescent response of A-H to Fe^3+ can be conveniently detected by the naked eye, providing a facile method for visual detection of Fe^3+. The proposed method was used to determine Fe^3+ in water samples. Moreover, inverted fluorescence microscopy imaging using human umbilical vein endothelial cells shows that A-H can be used as an effective fluorescent probe for detecting Fe^3+ in living cells.
基金supported by the National Natural Science Foundation of China (No. 21172178)
文摘A new rhodamine B derivative T1 has been rationally synthesized and displayed selective Pd(Ⅱ)-amplified absorbance and fluorescence emission above 540 nm in methanol-water. Upon the addition of Pd(Ⅱ), the spirolactam ring was unfolded and a 1:1 metal-ligand complex formed, which can be used for ''naked-eyes" detection. In addition, fluorescence imaging experiments of Pd^(2+) in HepG2 living cells showed its valuable application in biological systems.
文摘We demonstrate a deep-learning-based fiber imaging system that can transfer real-time artifact-free cell images through a meter-long Anderson localizing optical fiber.The cell samples are illuminated by an incoherent LED light source.A deep convolutional neural network is applied to the image reconstruction process.The network training uses data generated by a setup with straight fiber at room temperature(∼20°C)but can be utilized directly for high-fidelity reconstruction of cell images that are transported through fiber with a few degrees bend or fiber with segments heated up to 50°C.In addition,cell images located several millimeters away from the bare fiber end can be transported and recovered successfully without the assistance of distal optics.We provide evidence that the trained neural network is able to transfer its learning to recover images of cells featuring very different morphologies and classes that are never“seen”during the training process.
基金Project supported by State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources(Guangxi Normal University)(CMEMR2016-B12)the National Natural Science Foundation of China(31572492,21401031,21371103,31372482)+3 种基金the Innovative and Entrepreneurial Training Plan for Tianjin College Students(201710061035)the Natural Science Foundation of Tianjin(12JCZDJC22100)the General Fund of Application Foundation and Advanced Technology Program of Tianjin(14JCYBJC30000)the Veterinary Biotechnology Scientific Research Innovation Team of Tianjin,China(TD12-5019)
文摘Six binuclear rare earth compounds were synthesized through the ligand of 4-Bromo-N-hydroxy-Nmethyl-benzamide(sH_2 bha). Compounds 1-3 are isomorphous, and compound 1 is crystallized in the monoclinic system with the P2_1/c space group. Compounds 4 and 5 are isomorphous, and compound 4 is crystallized in the triclinic system with the P-1 space group. Compound 6 is crystallized in the triclinic system with the P-1 space group. The compounds were characterized by thermogravimetric analysis(TGA) and IR spectroscopy. The fluorescence spectrum in the visible area shows characteristic peaks of Eu, Tb, and Dy compounds. The efficiency of Eu compound on the viability of PC3 cells was assessed using CCK8 assays. From the CCK8 results, ionic concentration may have a great effect on PC3 cells' proliferation. Eu compound shows red fluorescence in the cytoplasm of PC3 cell. As for Eu compound, it might have potential application in cell imaging technology.
基金supported by the National Natural Science Foundation of China(Grant Nos.51972221 and 51803148)Central Government Guides Local Science and Technology Development Projects(YDZX20201400001722)+1 种基金the Shanxi Provincial Excellent Talents Science and Technology Innovation Project(201805D211001)the Natural Science Foundation of Shanxi Province(201901D211502 and 201901D211501).
文摘High fluorescence quantum yield(QY),excellent fluorescence stability,and low toxicity are essential for a good cellular imaging fluorescent probe.Green-emissive carbon quantum dots(CQDs)with many advantages,such as unique fluorescence properties,anti-photobleaching,low toxicity,fine biocompatibility and high penetration depth in tissues,have been considered as a potential candidate in cell imaging fluorescent probes.Herein,N,S-codoped green-emissive CQDs(QY=64.03%)were synthesized by the one-step hydrothermal method,with m-phenylenediamine as the carbon and nitrogen source,and L-cysteine as the nitrogen and sulfur dopant,under the optimum condition of 200℃ reaction for 2 h.Their luminescence was found to originate from the surface state.In light of the satisfactory photobleaching resistance and the low cytotoxicity,CQDs were used as a cell imaging probe for HeLa cell imaging.The results clearly indicate that cells can be labeled with CQDs,which can not only enter the cytoplasm,but also enter the nucleus through the nuclear pore,showing their broad application prospect in the field of cell imaging.
基金supported by the National Key Research Program(2018YFC1602900,2019YFA0905800)the National Natural Science Foundation of China(NSFC 21922404)the Science and Technology Project of Hunan Province(2017XK2103,2018JJ3034,2019SK2201,2018RS3035,2020SK3008)。
文摘Cells are the basic structural and functional units of organisms.Dynamic analysis and manipulation of specific components in living cells would provide valuable information for the study of related biological processes.Advances in fluorescence microscopy have allowed real-time monitoring of biological events at the molecular level.Meanwhile,the development of highperformance fluorescence probes has become a critical issue.Functional nucleic acids(FNAs)are oligonucleotides with special chemical and biological functions,and aptamers with excellent molecular recognition capability are one of the most important representatives.They have attracted extensive attention in the field of live-cell study,owing to intrinsic advantages of simple synthesis,convenient modification,low immunogenicity and high programmability.This review focuses on recent research progress in fluorescence imaging and manipulation of cells using FNAs,particularly aptamers,as the molecular tools.Finally,a summary is provided and the related challenges are discussed.
文摘In this study, we report a novel and facile autoclave strategy for synthesis of near-infrared (NIR) CulnS2 QDs by employing glutathione (GSH) as capping ligand and stabilizer in aqueous media under 100 ~C. Various experi- mental parameters including the ratio of precursors, reaction time, reaction temperature, pH effect and stability have been systematically studied. The QDs were characterized by X-ray diffraction (XRD), transmission electron micro- scope (TEM), and Fourier transform infrared spectroscopy (FT-IR). The as-synthesized NIR QDs exhibited low cytotoxicity and maintained excellent cell viability even up to 100 gg/mL. After bioconjugation with Arg-Gly-Asp (RGD) peptide, the obtained CulnS2-RGD QDs have demonstrated high targeting ability with good fluorescence cell imaging performance.