- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A highly specific and ultrasensitive p-aminophenylether-based fluorescent probe for imaging native HOCl in live cells and zebrafish
摘要： It is very important to detect native hypochlorous acid (HOCl) in the complex biosystems owing to the important roles of HOCl in the immune defense and the pathogenesis of numerous diseases. In this paper, a new p-aminophenylether-based fluorescent probe PAPE-HA was developed for specific detection of HOCl. Probe PAPE-HA could implement the quantitative detection of HOCl ranging from 0 to 1 μM and the detection limit was obtained as low as 1.37 nM. Additionally, probe PAPE-HA could reach a rapid response for HOCl (< 2 min). Importantly, probe PAPE-HA with preeminent specificity and ultrasensitivity was proven to possess powerful capability of tracking native HOCl in live cells and zebrafish, and we thus anticipate that probe PAPE-HA could be used as a novel promising tool for revealing diverse cellular functions of HOCl.
关键词： hydroxynaphthalimide,hypochlorous acid (HOCl),Fluorescent probe,p-aminophenylether,bioimaging
更新于2025-09-10 09:29:36
-
Nano Scale Potentiometric and Spectrophotometric Assays for 2,4-Dichlorophenoxyacetic Acid
摘要： The aim of this work was to investigate the ability of silicate wire ion selective electrode to measure 2,4 dichlorophenoxyacetic acid (2,4-D). The slope of the electrode was 56.2 mV decade -1 in the range from 10-6 to 10-2 M with lower limit of detection 8.3 × 10-7 M. The electrodes were successfully applied to determination of 2,4-D by separate and standard addition potentiometry. The electrode was used to detect the effect of pH and temperature on 2,4-D placed on baby watercress plant grown in the clay soil and the residue after five day from addition. Leaf chlorophylls quantity measured utilize spectrophotometric or colorimetric assay following extraction of pigments of watercress by ethanol. This work was carried at 286, 440, 662 nm. Beer’s law was obeyed in the concentration range of 2.21 mg/ml:2.21 μg/ml. The limits of detection were 2.21 μg/ml.
关键词： 2,4-Dichlorophenoxyacetic acid,Spectrophotometric,ion-selective electrodes,Wire,Chlorophyll,Potentiometric,Watercress
更新于2025-09-10 09:29:36
-
Quantitative fluorescence imaging determines the absolute number of locked nucleic acid oligonucleotides needed for suppression of target gene expression
摘要： Locked nucleic acid based antisense oligonucleotides (LNA-ASOs) can reach their intracellular RNA targets without delivery modules. Functional cellular uptake involves vesicular accumulation followed by translocation to the cytosol and nucleus. However, it is yet unknown how many LNA-ASO molecules need to be delivered to achieve target knock down. Here we show by quantitative fluorescence imaging combined with LNA-ASO microinjection into the cytosol or unassisted uptake that ～105 molecules produce >50% knock down of their targets, indicating that a substantial amount of LNA-ASO escapes from endosomes. Microinjected LNA-ASOs redistributed within minutes from the cytosol to the nucleus and remained bound to nuclear components. Together with the fact that RNA levels for a given target are several orders of magnitude lower than the amounts of LNA-ASO, our data indicate that only a minor fraction is available for RNase H1 mediated reduction of target RNA. When non-specific binding sites were blocked by co-administration of non-related LNA-ASOs, the amount of target LNA-ASO required was reduced by an order of magnitude. Therefore, dynamic processes within the nucleus appear to influence the distribution and activity of LNA-ASOs and may represent important parameters for improving their efficacy and potency.
关键词： RNase H1,Locked nucleic acid,nuclear accumulation,microinjection,gene knock down,antisense oligonucleotides,quantitative fluorescence imaging
更新于2025-09-10 09:29:36
-
Non-Fullerene Small Molecule Acceptors Containing Barbituric Acid End Groups for Use in High-performance OPVs
摘要： We synthesized two new bithiophene-based small molecules, TT-BBAR, and TT-OBAR, having butyl- and octyl-substituted barbituric acid (BAR) groups, respectively, via a well-known synthetic method, the Knoevenagel condensation, in high yield. These small molecules displayed solubilities and thermal stabilities sufficient for the fabricating organic photovoltaic cells (OPVs) and were designed to have relatively low molecular orbital energy levels and act as non-fullerene acceptors (NFAs) for use in OPVs upon introduction of electron-withdrawing BAR groups at both ends. For example, the LUMO and HOMO energy levels of TT-OBAR were ?3.79 and of ?5.84 eV, respectively, clearly lower than those of a polymer donor, PTB7-Th. Importantly, the small molecules featured an energy offset with PTB7-Th sufficient for achieving exciton dissociation. The optical and electrochemical properties of TT-BBAR and TT-OBAR did not depend on the alkyl chain length. Finally, OPV devices were fabricated in an inverted structure using a solvent process. The power conversion efficiency of TT-OBAR (1.34%) was found to be slightly higher than that of TT-BBAR (1.16%). The better performance and higher short-circuit current value of TT-OBAR could be explained based on a morphological AFM study, in which TT-OBAR displayed a more homogeneous morphology with a root-mean-square value of 1.18 nm compared to the morphology of TT-BBAR (11.7 nm) induced by increased alkyl chain length.
关键词： Barbituric acid,Organic photovoltaics,Organic photovoltaic cell,Non-fullerene acceptor
更新于2025-09-10 09:29:36
-
Photopolymerization synthesis of polyacrylic acid dispersant with methoxysilicon end groups and its application in nano-SiO <sub/>2</sub> aqueous system
摘要： In order to improve the dispersity and stability of nano-SiO2 aqueous system with high solid content, a kind of polyacrylic acid dispersant with methoxysilicon end groups (KH590-PAA) was synthesized by photopolymerization of acrylic acid (AA) initiated with (3-mercaptopropyl)trimethoxysilane (KH-590). After adding KH590-PAA into nano-SiO2 aqueous dispersion system (20 wt% solid content), the viscosity and the curing time of the system were measured by rotational viscometer and the inverted bottle method. Moreover, the dispersion mechanism of KH590-PAA for nano-SiO2 aqueous system was researched by measuring the adsorption capacity, the particle size and the zeta potential of nanoparticles with conductivity meter, dynamic light scattering (DLS), scanning electron microscope (SEM) and transmission electron microscope (TEM), respectively. The results showed that methoxysilicon groups in KH590-PAA could react with hydroxyl groups on the surface of nano-SiO2 in the process of stirring, which enhanced the adsorption capacity of the dispersant and then increased the surface charge of the particles. Therefore, electrostatic repulsion and steric hindrance effects between SiO2 nanoparticles could further be enhanced by adding the KH590-PAA dispersant, and then the nano-SiO2 aqueous system exhibited better dispersity and stability. Besides, the dispersion properties of SiO2 nanoparticles in water were closely related to the addition amount and the molecular weight of the KH590-PAA dispersant.
关键词： Dispersion,Photopolymerization,Silane coupling agent,SiO2 nanoparticle,Polyacrylic acid
更新于2025-09-10 09:29:36
-
Tailoring the Optical Properties of Organic D-π-A Photosensitizers: Effect of Sulfur Introduction in the Acceptor Group
摘要： In this work, we present for the first time the synthesis and characterization of potential DSSC organic sensitizers whose cyanoacrylic acceptor/anchoring group was modified by replacement of oxygen with one or more sulfur atoms. Using known carboxylic acid dye DF15 as a reference, their TD-DFT computational analysis indicated that oxygen-sulfur substitution should induce a significant red-shift of the corresponding UV-Vis absorption spectra. Whereas synthesis of monothiocarboxylic derivatives of DF15 was successfully carried out, isolation of the analogous dithiocarboxylic acid proved impossible due to its very low stability: despite that, their relative spectroscopic properties could be compared by analyzing the corresponding benzylic esters. Combined computational and transient absorption spectroscopy studies suggested that photoexcited thiocarboxylic acid 1-SO and thioamide 1-SN were able to inject electrons into nanocrystalline TiO2, and indicated a similar charge injection efficiency for 1-SO relative to DF15. Preliminary DSSC studies showed that, when t-butylpyridine was present in the electrolyte solution, 1-SO was rapidly degraded; however, in the absence of basic additives 1-SO provided a sufficiently stable device, giving a slightly lower efficiency compared to carboxylic sensitizer DF15.
关键词： thiocarboxylic acid,transient absorption spectroscopy,thioamide,Organosulfur compounds,dye-sensitized solar cells
更新于2025-09-10 09:29:36
-
A dual-targeted hyaluronic acid-gold nanorod platform with triple-stimuli responsiveness for photodynamic/photothermal therapy of breast cancer
摘要： Multi-stimuli-responsive theranostic nanoplatform integrating functions of both imaging and multimodal therapeutics holds great promise for improving diagnosis and therapeutic efficacy. In this study, we reported a pH, glutathione (GSH) and hyaluronidase (HAase) triple-responsive nanoplatform for HER2 and CD44 dual-targeted and fluorescence imaging-guided PDT/PTT dual-therapy against HER2-overexpressed breast cancer. The nanoplatform was fabricated by functionalizing gold nanorods (GNRs) with hyaluronic acid (HA) bearing pendant hydrazide and thiol groups via Au-S bonds, and subsequently chemically conjugating 5-aminolevulinic acid (ALA), Cy7.5 and anti-HER2 antibody onto HA moiety for PDT, fluorescence imaging and active targeting, respectively. The resulting versatile nanoplatform GNR-HA-ALA/Cy7.5-HER2 had uniform sizes, favorable dispersibility, as well as pH, GSH and HAase triple-responsive drug release manner. In vitro studies demonstrated that HER2 and CD44 receptor-mediated dual-targeting strategy could significantly enhance the cellular uptake of GNR-HA-ALA/Cy7.5-HER2. Under near-infrared (NIR) irradiation, MCF-7 cells could efficiently generate reactive oxygen species (ROS) and heat, and be more efficiently killed by a combination of PDT and PTT as compared with individual therapy. Pharmacokinetic and biodistribution studies showed that the nanoplatform possessed a circulation half-life of 1.9 h and could be specifically delivered to tumor tissues with an accumulation ratio of 12.8%. Upon the fluorescence imaging-guided PDT/PTT treatments, the tumors were completely eliminated without obvious side effects. The results suggest that the GNR-HA-ALA/Cy7.5-HER2 hold great potential for breast cancer therapy.
关键词： Triple-responsive drug release,Hyaluronic acid,Gold nanorod,Photodynamic and photothermal dual-therapy,Targeted delivery
更新于2025-09-10 09:29:36
-
A Rapid, Label-free and Impedimetric DNA Sensor Based on PNA-modified Nanoporous Gold Electrode
摘要： A gold nanoparticle film was successfully prepared on highly ordered and porous anodic aluminum oxide substrate through thermal evaporation deposition technique. As-fabricated nanoporous gold electrode modified by thiol-derivative peptide nucleic acid (PNA) was applied for impedimetric DNA sensing. In-situ kinetic analysis of PNA/DNA hybridization process was realized by electrochemical impedance spectroscopy (EIS) method. Considering the special structure of nanoporous gold electrode, a new equivalent circuit model was proposed for EIS data fitting. The sensitivity of PNA-modified nanoporous gold electrode is 0.4 Ω/cm2·nM. Meanwhile, complementary DNA target could be detected at concentration as low as 10 nM, which indicating that a methodology for rapid, sensitive and label-free detection of DNA has been set-up based on nanoporous gold electrode.
关键词： DNA sensing,nanoporous gold electrode,peptide nucleic acid,anodic aluminum oxide
更新于2025-09-10 09:29:36
-
A true oxygen-linked heptazine based polymer for efficient hydrogen evolution
摘要： O-doped/functional g-CN polymers are promising material which has been reported to modify inherent electronic structure and light harvest ability of the g-C3N4 based photocatalysts. However, the doping position and concentration of hetero atom remains ill-defined although enhanced photocatalytic activity of modified g-CN photocatalysts has been reported. Herein, a facile two step procedure to synthesize heptazine polymer with defined O-atom position in polymer structure is presented. Cyameluric acid, a member of cyamelurine family upon polycondensation under inert atmosphere ensures the insertion of O-atom at bridge position between heptazine units in growing polymer. The developed polymer OLHP (oxygen linked heptazine polymer) attains high hydrogen production efficiency likely due to high O-content and efficient charge separation evident from PL spectra compared to g-CN. This heptazine based precursor design also eliminates the possibility of presence of triazine based moiety defects in g-C3N4 polymers.
关键词： Water splitting,Heterogeneous photocatalysis,Cyameluric acid,Heptazine,carbon nitride
更新于2025-09-10 09:29:36
-
A series of lanthanide coordination polymers based on flexible bis?(imidazole?4,5?dicarboxylate) ligand: Syntheses, structures and fluorescent properties
摘要： A series of lanthanide coordination polymers, namely {[Ln(HL)(H2O)2]·H2O}n (Ln= Ce(1), Pr(2), Nd(3), Eu(4) and Tb(5); H4L = 1,1'-(propane-1,3-diyl)bis(1H-imidazole-4,5-dicarboxylic acid)) have been synthesized under hydrothermal conditions and characterized by infrared spectroscopy, element analysis, single-crystal X-ray diffraction, powder X-ray diffraction and thermogravimetric analyses. These isostructural complexes exhibit a 3D framework with a sra topology built by HL3? anions μ4?bridging metal ions through two IDC groups in different coordination modes. The luminescent property of complexes containing Eu(III) and Tb(III) have also been investigated in detail.
关键词： Lanthanide,Topology,Imidazole-4,5-dicarboxylic acid,Luminescence,Crystal structure
更新于2025-09-10 09:29:36