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- 实验方案
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Fluorescent Self-Healing Carbon Dot/Polymer Gels
摘要： Multicolor, fluorescent self-healing gels were constructed through reacting carbon dots produced from different aldehyde precursors with branched polyethylenimine. The self-healing gels were formed through Schiff base reaction between the aldehyde units displayed upon the carbon dots' surface and primary amine residues within the polyethylenimine network, generating imine bonds. The dynamic covalent imine bonds between the carbon dots and polymeric matrix endowed the gels with both excellent self-healing properties, as well as high mechanical strength. Moreover, the viscoelastic properties of the gels could be intimately modulated by controlling the ratio between the carbon dots and polymer. The distinct fluorescence emissions of the gels, originating from the specific carbon dot constituents, were employed for fabrication of light emitters at different colors, particularly generating white light.
关键词： imines,carbon dots,aldehydes.,dynamic covalent bonds,self-healing gels,fluorescent gels
更新于2025-09-23 15:23:52
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Diketopyrrolopyrrole Bisphosphonate Conjugate: A New Fluorescent Probe for in Vitro Bone Imaging
摘要： We report the synthesis of a conjugate molecule between an unusual red fluorescent diketopyrrolopyrrole (DPP) unit and a bisphosphonate (BP) precursor using the 'Click Chemistry' strategy to target bone tissue and monitor the interaction. After deep investigation, conjugation through a triazole unit between γ-azido rather than β-azido BP and an alkyne functionalized DPP fluorophore group turned out to be the winning strategy. Visualization of the DPP-BP conjugate on osteoclasts as well as the specific anti-resorption activity was successfully demonstrated.
关键词： fluorescent probe,in vitro imaging,osteoporosis,bisphosphonate,diketopyrrolopyrrole
更新于2025-09-23 15:23:52
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Phenanthroline-Derivative Functionalized Carbon Dots for Highly Selective and Sensitive Detection of Cu2+ and S2? and Imaging inside Live Cells
摘要： Developing effective methods for the instant detection of Cu2+ and S2? is highly desired in the biological and environmental fields. Herein, a novel fluorescent nanoprobe was elaborately designed and synthesized by grafting a phenanthroline derivative onto the surface of carbon dots (CDs). The obtained functionalized CDs (FCDs) exhibited blue fluorescence (FL) with excellent photostability and possessed a mean diameter around 4 nm. Cu2+ can be selectively captured by the phenanthroline group of FCDs to generate an absorptive complex in situ, leading to obvious quenching of the FCDs’ FL signal through an inner filter effect. Furthermore, the FL of the FCD–Cu2+ can be effectively recovered by S2? anions due to the release of FCDs from the FCD–Cu2+ complex owing to the formation of stable CuS (Ksp = 1.27 × 10?36) between S2? and Cu2+. The detection limits of the FCDs were determined to be 40.1 nM and 88.9 nM for Cu2+ and S2?, respectively. Moreover, this nanoprobe can also be used for the imaging of intracellular Cu2+ and S2?, which shows strong application prospects in the field of biology.
关键词： carbon dots,fluorescent nanoprobe,(2,3-f)-pyrazino(1,10)phenanthroline-2,3-dicarboxylic acid,Cu2+,S2?
更新于2025-09-23 15:23:52
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A Simple Colorimetric and Fluorescent Sensor to Detect Organophosphate Pesticides Based on Adenosine Triphosphate-Modified Gold Nanoparticles
摘要： A simple and dual modal (colorimetric and fluorescent) sensor for organophosphate pesticides with high sensitivity and selectivity using adenosine triphosphate (ATP)- and rhodamine B-modified gold nanoparticles (RB-AuNPs), was successfully fabricated. This detection for ethoprophos afforded colorimetric and fluorescence imaging changes visualization. The quantitative determination was linearly proportional to the amounts of ethoprophos in the range of a micromolar scale (4.0–15.0 μM). The limit of detection for ethoprophos was as low as 37.0 nM at 3σ/k. Moreover, the extent application of this simple assay was successfully demonstrated in tap water samples with high reliability and applicability, indicating remarkable application in real samples.
关键词： multimodal assay,ethoprophos detection,gold nanoparticles,colorimetric and fluorescent sensor,organophosphate pesticides
更新于2025-09-23 15:23:52
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Synthesis, Crystal Structure and Fluorescent Property of a Onedimensional Coordination Polymer Constructed By 1,3-Bis(1,2,4-Triazol-1-Ylmethyl)- Benzene And 4,4′-Oxydiphthalic Acid
摘要： A one-dimensional Cd(II) complex [Cd(H3ODPT)2(MBTZ)2?2H2O]n (1) (MBTZ = 1,3-bis(1,2,4-triazol-1-yl-methyl)benzene, H4ODPT = 4,4′-oxydiphthalic acid) is synthesized and characterized using single crystal X-ray diffraction, IR spectroscopy, and elemental analysis. Single crystal X-ray diffraction analysis reveals that complex 1 is a one-dimensional double chain polymer containing 24-membered rings with MBTZ ligands as the bridges arranged parallel to the b crystal direction, while the singly deprotonated H4ODPT ligands are extended on both sides of such double chains. In addition, the luminescence measurements reveal that complex 1 exhibits strong fluorescent emission in the solid state at room temperature.
关键词： 4,4′-oxydiphthalic acid,1,3-bis(1,2,4-triazol-1-ylmethyl)benzene,fluorescent property,Cd(II) complex,crystal structure
更新于2025-09-23 15:23:52
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One-pot three-component synthesis and photophysical properties of highly fluorescent novel 4-alkyl-3-aryl-2,6-dicyanoanilines by using tris(hydroxymethyl)aminomethane as a catalyst
摘要： Novel 4-alkyl-3-aryl-2,6-dicyanoanilines were synthesized by a multi-component one-step reaction of aromatic aldehyde, malononitrile and aliphatic aldehyde using tris(hydroxymethyl)aminomethane (THAM) as a catalyst under microwave (MW) irradiation or conventional heating. The optimized reaction condition involved use of 2.5 equivalents of THAM under MW irradiation at 140 W using 20 % MW power for 5 min or conventional heating at 80 °C for 8 h in dimethylformamide. The photophysical properties including λmax, quantum yield and Stokes’ shifts of newly synthesized molecules were studied. All compounds exhibited quantum yield in the range of 0.04 to 0.52 with respect to standard quinine sulphate having quantum yield 0.54. The Stokes’ shifts of all compounds were found in the range of 41-105 nm. The current strategy provides operationally simple protocol using THAM as a catalyst to synthesize 4-alkyl-3-aryl-2,6-dicyanoanilines with diverse structural features to make them available for exploration of their photophysical as well as biological applications.
关键词： Fluorescent,Quantum Yield,Tris(hydroxymethyl)aminomethane,Microwave,Malononitrile,Dicyanoanilnes
更新于2025-09-23 15:23:52
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Mitochondria-targeted ratiometric fluorescent probes for micropolarity and microviscosity and their applications
摘要： Ambient polarity and viscosity are two important parameters that influence many chemical and biological processes of biomolecules. In biological systems especially at the cellar level, polarity affects the interaction of many proteins and enzymes as well as the cell membrane permeability. Microenvironmental viscosity has a marked impact on some physiological processes such as cellular material transportation, interactions between biological macromolecules, diffusion of reactive substances. Abnormal changes in polarity and/or viscosity have been considered as vital causes or indicators for some diseases and malfunctions such as diabetes and Alzheimer's disease. Detection of microenvironmental polarity and/or viscosity has caused much interest in many scientific areas. Mitochondria are important organelles of energy production as well as major sites of aerobic respiration in eukaryotes. They are also involved in lots of significant processes including protein translocation, the synthesis of ATP, the transportation of metabolites, etc. The mitochondrial functions are closely linked with physical chemical properties of mitochondria, namely polarity, viscosity, pH and temperature. Therefore, monitoring the changes in mitochondrial polarity and/or viscosity is fruitful for understanding some important physiological processes. However, conventional viscometers and polarity detectors are not suitable for the measurements at the cellar level. It is highly desired to develop new techniques for fast quantifying cellar polarity and viscosity. Fluorescence-based techniques have been widely applied in many scientific researches due to the merits of good accuracy, extremely high sensitivity, temporal and spatial resolution and especially bioimaging in living cells. Numerous polarity-sensitive sensors have been developed for detection of cellar polarity based on intramolecular charge transfer (ICT) mechanism. For viscosity tests, 'molecular rotors' have been proved to be promising probes for their excellent photophysical properties of ratiometric fluorescence and/or fluorescence lifetime imaging. Nevertheless, probe possesses features of both ICT and molecular rotor and could monitor polarity and viscosity simultaneously has rarely been reported. Coumarin is a well-known polarity-sensitive fluorophore, and many coumarin-based probes have been constructed for polarity. Normally, the structural characteristic of a molecular rotor is that a steric group covalently linked to a planar fluorophore with a single/double bond as the connecting rotation shaft. In view of the above points, we envisioned that if a steric group linked to a polarity-sensitive fluorophore, it may detect polarity and viscosity simultaneously. Herein, two compounds YYH1 and YYH2 with coumarin as the fluorophore and N-methyl indole as the steric group were selected to quantify microenvironmental polarity and viscosity. Compared to those with similar fluorophore reported in the references, our probes were more sensitive to polarity and/or viscosity and have longer emission wavelengths (λem = 685 nm for YYH2). Furthermore, the cationic characteristics of both compounds endows them locating in mitochondria in living cells. With compounds YYH1 and YYH2 (NMR and mass spectra are shown in Figs. S1 and S2 in Supporting information) in hand, we first investigated their photophysical properties in phosphate buffered solution (PBS). Fig. S3 (Supporting information) demonstrates that both compounds have one absorption and two emission peaks in PBS. The emission peaks of shorter wavelengths could be ascribed to the part without indole moiety. The red emission bands are resulted from the whole π-conjugation system, which are sensitive to the solvent viscosity. The emission (681 nm) and absorption (597 nm) maxima of YYH2 are at the red wavelength region and about 30 nm longer than those of YYH1, which enables the probe to be potentially applied in biological systems. Considering the strong ICT characteristic from the aminocoumarin unit to the indole part, the solvent-dependent spectral properties were studied. Both compounds display solvatochromic absorption and emission spectra (Figs. S4 and S5 in Supporting information). The absorption maximum of YYH1 shifted from 628 nm in toluene to 565 nm in PBS, while the green emission moved from 462 nm to 478 nm in the same series of solvents. However, the red emission showed little change upon polarity variation (Fig. S6 in Supporting information). Good relationship between absorption/emission wavenumber and the solvent polarity parameters (ET) verifies the ICT characteristic of the green emission (Fig. S6). The polarities of cationic compounds YYH1 and YYH2 are greater in ground state than in excited state, therefore, the absorption wavelength decreased with increasing polarity. Nevertheless, the green emission wavelength increased with increasing polarity, suggesting that the indole cation section was not involved in the green emission. In 1,4-dioxane-water binary mixture, with increasing water content, the absorption peak shifted from 613 to 565 nm and 647 to 597 nm for YYH1 and YYH2, respectively (Fig. S7 and S8 in Supporting information). The emission wavelength of YYH1 shifted from 468 nm to 478 nm without obvious intensity change when the proportion of the polar solvent water increased from 10% to 20% (Fig. 1a). Further increasing water content resulted in significant decrease in fluorescence intensity of the green emission with no appreciable wavelength change, whereas the emission at 645 nm increased steadily, with an isoemission point at 598 nm (Fig. 1a). More than 150 nm wavelength difference between the two bands provides a ratiometric response. The ratio I490/I645 decreased dramatically from 27 to 0.5 with increasing water content from 20% to 100% suggesting that YYH1 could be a potential ratiometric fluorescent probe for microenvironmental polarity. In the case of YYH2, when water content changed from 0 to 40%, both the blue (515 nm) and red (685 nm) emissions increased; while they both decreased with further increment of water content (Figs. S8b and c). The fluorescence intensity ratio I515/I685 hardly changed with water content revealing that YYH2 is insensitive to polarity (Fig. 1b). Then the spectral responses of YYH1 and YYH2 toward arbitrary changes in the viscosity were tested to understand the viscosity effect. The experimental results illustrate that YYH1 and YYH2 respond to the viscosity in different ways. In glycol-water mixed system, the absorbance at 595 nm of YYH2 increased slightly accompanied with about 12 nm red-shift with increasing glycol content, which could be probably attributed to the slight decrease of the polarity (Fig. S9 in Supporting information). As shown in Fig. 2a, the red emission of YYH2 is more sensitive to solvent viscosity than the green one: with increasing solvent viscosity from 1.0 (water) to 19.9 cp (glycol), about 10-fold and 1.7-fold fluorescence enhancements respectively for the red and green emissions were observed. The enhancement in the green emission was possibly attributed to the variation in solution's polarity. Good linear relationship between log (I685/I515) and logη of the solvent reveals that YYH2 could be applied in ratiometric detection of the media viscosity. The quantitative relationship between the ratio of I685/I515 and the solvent viscosity η is well expressed by F?rster-Hoffmann equation: log(I685/I515) = C + xlogη (C = ?0.673, x = 0.634, R2 = 0.968), where C is a concentration and temperature-dependent constant and x is a dye-dependent constant. In addition, the fluorescence life time of YYH2 also became slightly longer with increasing solution viscosity (Fig. S10 in Supporting information): It was 0.3, 0.47 and 1.46 ns in water, 1:1 water-glycol and glycol, respectively. As for YYH1, about 8 nm blue-shift of the absorption maximum was found with increasing water content from 0 to 100%. The fluorescence intensities at 490 nm and 645 nm increased to almost the same extent (Fig. S11 in Supporting information), and the ratio of I645/I490 hardly changed with viscosity (Fig. 2b). From the above results, it is clear that YYH1 and YYH2 could be employed to detect local polarity and viscosity, respectively. To evaluate the biological application of the probes, we tested both compounds in living cells (Fig. 3). The localization of the probes in two living cell lines, L929 and MCF-7 cells, were determined by co-staining cells with mitrochondria-specific dye. The bright red fluorescent region with YYH1 (a2, b2) and green signals from Mitro Tracker Green FM (a1, b1) overlapped perfectly (a4, b4). A high Pearson correlation factor Pf of 0.91 for L929 cells (0.94 for MCF-7 cells) indicates that YYH1 is a mitrochondria-targeted dye. Similar results were obtained in the case of YYH2 (Figs. 3c and d) (Pf are 0.93 and 0.92 for L929 and MCF-7 cells, respectively), revealing that both probes could localize at mitrochondria. In living cells, proteins and some other biologically related substances are the main components and involved in every process within cells. The fluctuation of protein contents could affect cellar polarity or viscosity. To verify the effectiveness and practicability of the probes in realistic samples, the effects of some biological molecules on the spectral properties of YYH1 and YYH2 were measured. Table S1 (Supporting information) showed that both the ratio I490/I645 of YYH1 and the ratio I685/I515 of YYH2 became higher upon the addition of proteins (Fig. S12-S13 in Supporting information), revealing that the presence of proteins increased the microenvironmental viscosity and decreased the microenvironmental polarity of the probes. Furthermore, it is obvious that the viscosity and polarity varied with proteins (Table S1 in Supporting information), which means that the difference in protein content and/or protein species could cause the change in cellar viscosity and polarity. It is reported that probes YYH1 and YYH2 exhibited spectral responses toward sulfite. Other relevant species except for peroxynitrite hardly influence the photophysical properties of the probes. Therefore, the presence of sulfite or peroxynitrite could interfere with bioimaging to some extent. However, it is difficult for detection of peroxynitrite in living cells by traditional analytical methods due to its short half-life under typical physiological conditions. Sulfite content in living cells is relatively low because it could easily be oxidized to sulfate by sulfite oxidase. The interference from these ions could be neglected. On the other hand, the presence of sulfite resulted in the same variation tendency of Iblue/Ired for both probes. However, the change trends of Iblue/Ired for YYH1 and YYH2 caused by polarity/viscosity were quite different. Therefore, interference from sulfite could be distinguished by using both probes for bioimaging. Next, YYH1 and YYH2 were employed to estimate the polarity and viscosity in living cells, respectively. After MCF-7 and L929 cells incubated with YYH1 (5 μmol/L) for 30 min, blue and red imaging were collected. Strong intracellular blue fluorescence and weak intracellular red fluorescence were observed in both cells. Considering that the ratio of I490/I645 (i.e. I645/I490 in Fig. 2b) hardly changed with solvent viscosity, the ratio of Iblue/Ired may indicate that the mitochondrial polarity in L929 cells is smaller than that in MCF-7 cells (Fig. 4). After incubated with YYH2 (5 μmol/L) for 30 min, brighter intracellular green fluorescence was observed in MCF-7 cells, while stronger intracellular red fluorescence was observed in L929 cells (Fig. 5). The ratio of Ired/Igreen suggests that the mitochondrial viscosity in L929 cells is larger than that in MCF-7 cells. In summary, we have synthesized two mitochondria-targeted ratiometric fluorescent probes YYH1 and YYH2 for quantification of micropolarity and microviscosity, respectively. Both probes were constructed with environment-sensitive coumarin and N-methyl indole linked through a C-C bridge. YYH1 responded to the polarity, while YYH2 responded to the viscosity sensitively. Therefore, they were used for ratiometric fluorescent detection of the mitochondrial polarity and viscosity respectively. This work may provide some ideas for design of polarity and/or viscosity fluorescent probes for bioimaging living cells.
关键词： Mitochondria,Microviscosity,Micropolarity,Fluorescent probe
更新于2025-09-23 15:23:52
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A highly efficient fluorescent material based on rare-earth-modified polyhydroxyalkanoates
摘要： Fluorescent materials play an important role in biomedical fields. However, the main types of fluorescent materials suffer from several disadvantages especially the biotoxicity, which largely restrict its wider applications in biological fields. In this study, a highly efficient rare-earth-modified fluorescent material was successfully designed and fabricated based on polyhydroxyalkanoates, which are known as biodegradable and biocompatible material. A new Functional-PHA polymer was microbially synthesized by engineered Halomonas bluephagenesis and was used as a basal matrix to generate the rare-earth-modified PHA. N-acetyl-L-cysteine-grafted PHA (NAL-grafted-PHA) was first produced via a UV-initiated thiol-ene click reaction and the rare earth metal ions (Eu3+ and Tb3+) were subsequently chelated onto the NAL-grafted-PHA through the coordination effect. The composite material exhibited intense photoluminescence properties under UV laser excitation, indicating the excellent features as fluorescent material. The enhanced hydrophilicity and superior biocompatibility of rare earth-chelated PHA were confirmed, suggesting its great potential application value in biomedical fields.
关键词： Halomonas,photoluminescence,next generation industrial biotechnology,fluorescent material,polyhydroxyalkanoates,PHB,Rare-earth metal ions
更新于2025-09-23 15:23:52
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Novel rhodamine-based colorimetric and fluorescent sensor for the dual-channel detection of Cu2+ and Co2+/trivalent metal ions and its AIRE activities
摘要： A rhodamine hydrazone 1 bearing coumarin moiety was designed and prepared. Compound 1 exhibited high selectivity toward Co2+ and trivalent metal ions with fluorescence enhancement in CH3OH solution. However, 1 selectively responded to Al3+ in nearly pure H2O media and was further applied to monitor Al3+ in live cells. Moreover, 1 could also act as a colorimetric probe toward Cu2+ in either CH3OH or H2O solution. In addition, sensor 1 displayed aggregation-induced ratiometric emission (AIRE) activities in mixed H2O/CH3OH solution.
关键词： cell imaging,coumarin,fluorescent probe,Aggregation-induced ratiometric emission,metal ions,rhodamine
更新于2025-09-23 15:23:52
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NIR-Fluorescent Multidye Silica Nanoparticles with Large Stokes Shifts for Versatile Biosensing Applications
摘要： We have synthesized and characterized of a series of single and multidye copolymerized nanoparticles with large to very large Stokes shifts (100 to 255 nm) for versatile applications as standalone or multiplexed probes in biological matrices. Nanoparticles were prepared via the St?ber method and covalently copolymerized with various combinations of three dyes, including one novel aminocyanine dye. Covalently encapsulated dyes exhibited no significant leakage from the nanoparticle matrix after more than 200 days of storage in ethanol. Across multiple batches of nanoparticles with varying dye content, the average yields and average radii were found to be highly reproducible. Furthermore, the batch to batch variability in the relative amounts of dye incorporated was small (relative standard deviations <2.3%). Quantum yields of dye copolymerized nanoparticles were increased 50% to 1000% relative to those of their respective dye-silane conjugates, and fluorescence intensities were enhanced by approximately three orders of magnitude. Prepared nanoparticles were surface modified with polyethylene glycol and biotin and bound to streptavidin microspheres as a proof of concept. Under single wavelength excitation, microsphere-bound nanoparticles displayed readily distinguishable fluorescence signals at three different emission wavelengths, indicating their potential applications to multicolor sensing. Furthermore, nanoparticles modified with polyethylene glycol and biotin demonstrated hematoprotective qualities and reduced nonspecific binding of serum proteins, indicating their potential suitability to in vivo imaging applications.
关键词： Fluorescent silica nanoparticles,Biocompatible nanoparticles,Large stokes shift,Near-infrared fluorescence,Multicolor assay,Resonance energy transfer
更新于2025-09-23 15:23:52