修车大队一品楼qm论坛51一品茶楼论坛,栖凤楼品茶全国楼凤app软件 ,栖凤阁全国论坛入口,广州百花丛bhc论坛杭州百花坊妃子阁

oe1(光电查) - 科学论文

438 条数据
?? 中文(中国)
  • Visualizing Nitric Oxide in Mitochondria and Lysosomes of Living Cells with N-Nitrosation of BODIPY-based Fluorescent Probes

    摘要: Nitric oxide (NO), a ubiquitous gasotransmitter which plays critical roles in cardiovascular, nervous, and immune systems related diseases, is closely related in the physiological and pathological processes of mitochondria and lysosomes. Thus, monitoring NO in mitochondria or lysosomes is very meaningful for NO related chemical biology. Herein, we rationally designed four NO probes, BDP-NO, Mito-NO-T, Mito-NO and Lyso-NO, based on BODIPY dye substituted at meso position with 5-amino-2-methoxy-phenyl scaffold. These four probes all showed fast fluorescence off-on response toward NO with excellent selectivity and high sensitivity with the detection limit of BDP-NO to reach 5.7 nM. We introduced triphenylphosphonium and morpholine moieties onto BODIPY scaffold respectively to enable organelle-targetability. MTT and flow cytometry assay demonstrated that the probes exhibited low cytotoxicity, which was beneficial to the biological application in living cells. Confocal fluorescence microscopy experiments confirmed excellent mitochondria targeting for Mito-NO and lysosome-targeting with Lyso-NO for the detection of NO in living cells.

    关键词: Fluorescent probes,Mitochondria-targeted,Lysosomes-targeted,BODIPY,Nitric oxide

    更新于2025-11-21 11:08:12

  • A sequential and reversibility fluorescent pentapeptide probe for Cu(II) ions and hydrogen sulfide detections and its application in two different living cells imaging

    摘要: In this study, we report a sequential and reversibility fluorescent probe (DP5) based on pentapeptide conjugated with dansyl groups using the solid phase peptide synthesis (SPPS) technology. DP5 showed immediate “turn off” response toward Cu2+ ions at an excitation wavelength of 330 nm with detection limits of 23.5 nM. The 2:1 binding ratio between DP5 and Cu2+ were confirmed using Job's plot method and fluorescence titration study, and DP5-Cu complex was observed with an association constant of 6.76 × 108 M?2. As designed, DP5-Cu complex as a promising analytical probe exhibited highly selective for H2S detection in aqueous solutions. The detection limit for H2S was obtained to be 17.2 nM, and lower than EPA and WHO guidelines. In addition, the reversibility and cyclicity were imparted to the DP5 during the detection of Cu2+ and H2S, and cycle effect is very good. Furthermore, DP5 displayed better biocompatibility and low biotoxicity, and sequential fluorescence “on-off-on” responses of DP5 to Cu2+ and H2S were successfully applied in two different living cells.

    关键词: Cu2+ ions,Pentapeptide,Fluorescent probe,Cell imaging,Hydrogen sulfide,Aqueous solutions

    更新于2025-11-21 11:08:12

  • AIE active fluorescent organic nanoaggregates for selective detection of phenolic-nitroaromatic explosives and cell imaging

    摘要: Development of organic nanoparticles with high fluorescence, good biocompatibility along with strong resistance to photobleaching through simple synthetic routes is important for diverse applications such as sensing and bioimaging. Herein, we present the development of a pyrene excimer nanoaggregate which shows aggregation induced emission (AIE) effect in a solvent mixture of THF and water. The pyrene based fluorescent probe, dimethyl-5-(pyren-1-ylmethyleneamino)isophthalate (5-DP) was synthesized through a simple single step condensation reaction from inexpensive reagents. The photophysical studies of nanoaggregated system further corroborates the AIE active behavior of 5-DP probe at different water fractions (?w = 0% to 90%), where the hydrogen bonding interaction between imine and water molecules led to suppression of photoinduced electron transfer (PET) inducing significant enhancement in fluorescence. The highly photostable nanoaggregates were explored as a selective fluorescence “turn off” sensor for phenolic nitroaromatics and the chemo-selectivity was highly pronounced for 2,4,6-trinitrophenol (picric acid), that showed efficient quenching in aqueous as well as solid phase, with a detection limit of 10 nM in aqueous medium. The quenching efficiency of the nanoaggregates can be ascribed to a combination of factors including efficient fluorescence resonance energy transfer, inner filter effect and coulombic interaction between picric acid and the aggregated probe molecules. Further, random aggregation of the pyrene derivative could be controlled for the formation of fluorescent spherical nanoparticles using Pluoronics P-123 block copolymers as encapsulating agents. The resulting composite could be used as a neoteric cell imaging probe with significantly less cytotoxicity, thus showing their potential biological applications.

    关键词: aggregation induced emission,electron transfer,explosive detection,cell imaging,Fluorescent organic nanoaggregates

    更新于2025-11-21 11:03:13

  • Monitoring plasmonic hot-carrier chemical reactions at the single particle level

    摘要: Plasmon excitation in metal nanoparticles triggers the generation of highly energetic charge carriers that - properly manipulated and exploited - can mediate chemical reactions. Single-particle techniques are key to unearth the underlying mechanisms of hot-carrier generation, transport and injection as well as to disentangle the role of the temperature increase and the enhanced near-field at the nanoparticle-molecule interface. Gaining a nanoscopic insight of these processes and their interplay could aid in the rational design of plasmonic photocatalysts. Here, we present three different approaches to monitor hot-carrier reactivity at the single-particle level. We use a combination of dark-field microscopy and photo-electrochemistry to track a hot-hole driven reaction on a single Au nanoparticle. We image hot-electron reactivity with sub-particle spatial resolution using nanoscopy techniques. Finally, we push the limits looking for a hot-electron induced chemical reaction that generates a fluorescent product, which should enable imaging of active plasmonic photocatalysis at the single-particle and single-molecule levels.

    关键词: dark-field microscopy,fluorescent product,single-particle techniques,Plasmonic hot-carriers,plasmonic photocatalysis,photo-electrochemistry,nanoscopy techniques

    更新于2025-11-19 16:56:42

  • A red-emitting fluorescent probe with large Stokes shift for real-time tracking of cysteine over glutathione and homocysteine in living cells

    摘要: Fluorescent probes with high quality for highly selective detection of cysteine (Cys) are still urgently in demand because of the indispensable roles Cys plays in the biological systems. Herein, a red-emitting fluorescent probe CP was developed for the highly selective detection of Cys over glutathione (GSH) and homocysteine (Hcy) by incorporating the recognition unit into the 2-(2-(4-hydroxystyryl)-6-methyl-4H-pyran-4-ylidene) malononitrile (P-OH) fluorophore which is characterized by red emission, noteworthy Stokes shift, and appreciable photostability. Basically, CP demonstrated appreciable sensing performance toward Cys including short response time of 4 min, high sensitivity with approximately 147-fold emission enhancement, low detection limit of 41.696 nM, and good selectivity both in the solution and living cells, indicating its promising potential of visualizing Cys in biological systems.

    关键词: Large Stokes shift,Fluorescence imaging,Cysteine detection,Fluorescent probe

    更新于2025-11-19 16:56:35

  • Two pH-responsive fluorescence probes based on indole derivatives

    摘要: Two new pH ?uorescent probes 2,8-bis((E)-2-(1,1-dimethyl-1H-benzo[e]indol-2-yl)vinyl)-6H,12H-5,11-methanodibenzo[b,f][1,5]diazocine (1) and 2,8-bis((E)-2-(3,3-dimethyl-3H-indol-2-yl)vinyl)-6H,12H-5,11-methanodibenzo[b,f] [1,5]diazocine (2) were designed and synthesized via ethylene bridging of the Tr?ger's Base (TB) framework and indole derivatives. As the protonation of nitrogen atoms of indole derivatives, both probes displayed the signi?cant pH-dependent spectral properties. The probing behavior toward pH variations indicated that probes exhibited excellent pH dependent behavior in the pH ranges of 2.07–7.01 (1) and 1.96–7.01 (2), especially possessing good linear response in the pH ranges of 2.50–4.00. The emissions of 1 can be reversibly switched between brilliant yellow and dark states by protonation and deprotonation. Also, the yellow-green ?uorescence emission of 2 could be quenched upon protonation. Such behaviors enable them to work as turn-o? ?uorescent pH sensors in the solution state. Furthermore, protonation and deprotonation on indole moiety nitrogen of the probe 1 and 2 provided a sensing mechanism for pH changes. In addition, both probes performed good photostability, high selectivity and excellent reversibility.

    关键词: Sensors,Fluorescent probe,pH detection,Luminescence,Indole derivatives

    更新于2025-11-19 16:56:35

  • Synthesis and photophysics of a series of lipophilic phosphazene-based fluorescent indicators

    摘要: This work explores the 7‐amino‐4‐(trifluoromethyl)coumarin backbone for designing lipophilic fluorescent pH indicators. Four novel phosphazene bases with an advantageous combination of properties—high lipophilicity of both neutral and charged forms, lack of localized charges in the cations, and prominent spectral changes upon protonation/deprotonation—were synthesized using the Staudinger reaction. The molecular structures of the synthesized compounds were confirmed using attenuated total reflectance Fourier‐transform infrared spectroscopy (ATR‐FT‐IR), nuclear magnetic resonance (NMR), and Fourier‐transform ion‐cyclotron resonance (FT‐ICR) high‐resolution mass spectrometry. The compounds were further characterized by ultraviolet‐visible (UV‐Vis) absorption and fluorescence emission spectra, lipophilicities (logP values) and pKa values in water and acetonitrile, as well as “biphasic” pKa values in the water/1‐octanol solvent system. The bases could potentially be useful as working agents in optical pH sensors and acid‐base indicators for lipophilic membranes.

    关键词: partition coefficients,fluorescence,phosphazenes,fluorescent indicator,lipophilic indicators

    更新于2025-11-19 16:56:35

  • An AND logic gate-based fluorescence probe for the detection of homovanillic acid, an indicator of the tumor

    摘要: Homovanillic acid (HVA) is one of the major metabolites of catecholamine in human. An elevated level of HVA in urine and blood has been associated with many diseases, including catecholamine-secreting tumors. Consequently, detection of the biomarker HVA in urine is an effective strategy to detect cancer precursors and early stage cancers. In this study, a fluorescence probe is designed and fabricated by integrating lanthanide ions with metal-organic frameworks (MOFs). The fluorescence probe shows distinguished response toward HVA and exhibits ratiometric detection of HVA, rendering it an excellent candidate for sensing devices. Thus, we have designed logic gate operation integrating the probe with logical operations for the intelligent sensing of HVA. Furthermore, this type of luminesce based sensors integrated with logic gate augur for the further application in real-time early diagnosis of tumors in the future.

    关键词: Rare earth,Homovanillic acid,Fluorescent probe,Logic gate,Ratiometric sensing,Metal-organic frameworks

    更新于2025-11-19 16:56:35

  • Highly Sensitive and Selective Fluorescent Sensor based on a Multi-Responsive Ultrastable Amino-Functionalized Zn(II)-MOF for Hazardous Chemicals

    摘要: A microscale amino-functionalized Zn(II)-MOF, namely [Zn(NH2-bdc)(4,4’-bpy)] (1) (NH2-H2bdc = 2-amino-1,4-benzenedicarboxylic acid and 4,4’-bpy = 4,4’-bipyridine), has been successfully synthesized, structurally characterized and further utilized as multi-responsive fluorescent sensor for highly sensitive and selective detection of Cr(VI) and 2,4,6-trinitrophenol (TNP). Compound 1 features non-porous 5-fold interpenetrated 3D framework with the Lewis basic sites including the uncoordinated amino and carboxylate groups on the framework for anchoring and recognizing the guest. 1 exhibits not only excellent water and thermal stability but also tolerance to acidic and basic media over an extensive pH range of 2-12. This ultrastable material can sensitively and selectively detect Cr2O7 2- and CrO4 2- in water based on the luminescent quenching with relatively low limits of detection (2.21 μM for CrO4 2- and 1.30 μM for Cr2O7 2-). Moreover, the unprecedented solvent-dependent luminescent response of 1 as a fluorescent probe for high-efficiency TNP detection was observed. Significantly, 1 not only displays high sensitive fluorescent enhancement upon TNP binding in ethanol but also exhibits fluorescent quenching toward TNP in water with very low limits of detection of 4.47 nM and 0.32 μM in ethanol and water, respectively. This work reports the first example of the utilization of MOF as a sensor for the detection of TNP based on dual responsive luminescence. Importantly, 1 can be simply and rapidly regenerated, displaying excellent recyclability after the sensing experiments.

    关键词: Multi-responsive fluorescent sensors,Fluorescent quenching,Metal-organic framework,2,4,6-trinitrophenol,Fluorescent enhancement,Cr(VI)

    更新于2025-11-19 16:46:39

  • A Red Emitting Fluorescent Probe for Imaging Mitochondrial Hydrogen Polysulfide in Living Cells and Tissues

    摘要: Hydrogen polysulfide (H2Sn) has attracted increasing attention since H2Sn instead of H2S has been shown to be the actual signaling molecule in physiological and pathological processes. Thus, developing accurate and sensitive assays for H2Sn detection is urgently needed in biological science. In this work, we developed a red emitting mitochondria-targeting fluorescent probe, HQO-PSP, that is capable of tracking H2Sn. With low cytotoxicity, good selectively and high sensitively, HQO-PSP was able to detect H2Sn in living cells. Furthermore, we also demonstrated that HQO-PSP could also be successfully applied to recognize H2Sn in living tissues.

    关键词: Hydrogen polysulfide,Fluorescent probe,Lung tissues,Living cells

    更新于2025-11-19 16:46:39