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131.
Yi‐Chin Chen Sheng‐Cih Huang Dr. Yu‐Kuo Wang Dr. Yuan‐Ting Liu Prof. Dr. Tung‐Kung Wu Prof. Dr. Teng‐Ming Chen 《化学:亚洲杂志》2013,8(11):2652-2659
In this study, surface‐functionalized, branched polyethylenimine (BPEI)‐modified YVO4:Bi3+,Eu3+ nanocrystals (NCs) were successfully synthesized by a simple, rapid, solvent‐free hydrothermal method. The BPEI‐coated YVO4:Bi3+,Eu3+ NCs with high crystallinity show broad‐band excitation in the λ=250 to 400 nm near‐ultraviolet (NUV) region and exhibit a sharp‐line emission band centered at λ=619 nm under excitation at λ=350 nm. The surface amino groups contributed by the capping agent, BPEI, not only improve the dispersibility and water/buffer stability of the BPEI‐coated YVO4:Bi3+,Eu3+ NCs, but also provide a capability for specifically targeted biomolecule conjugation. Folic acid (FA) and epidermal growth factor (EGF) were further attached to the BPEI‐coated YVO4:Bi3+,Eu3+ NCs and exhibited effective positioning of fluorescent NCs toward the targeted folate receptor overexpressed in HeLa cells or EGFR overexpressed in A431 cells with low cytotoxicity. These results demonstrate that the ligand‐functionalized, BPEI‐coated YVO4:Bi3+, Eu3+ NCs show great potential as a new‐generation biological luminescent bioprobe for bioimaging applications. Moreover, the unique luminescence properties of BPEI‐coated YVO4:Bi3+,Eu3+ NCs show potential to combine with a UVA photosensitizing drug to produce both detective and therapeutic effects for human skin cancer therapy. 相似文献
132.
133.
The internal redox esterification of α,β-unsaturated aldehydes and alcohols was carried out using different ionic liquids (ILs) as catalysts and reaction solvents. The basic ionic liquid, 1-butyl-3-methylimidazolium acetate ([bmim]OAc), exhibited the best activity for this reaction. The influences of the amount of ionic liquid catalyst and reaction time on yield of saturated ester have been investigated. The results showed that ionic liquid anions have a crucial effect on the redox esterification of α,β-unsaturated aldehydes and alcohols. The nucleophilic carbenes generated in situ from the ionic liquid cation were believed to be actual active species for this reactions. 相似文献
134.
Jun‐Ju Xu Da‐Ke Zhao Hong‐Lian Ai Li‐Mei Zhang Shi‐Qing Xie Shu‐Hui Zi Sheng‐Chao Yang Yong Shen 《Helvetica chimica acta》2013,96(11):2155-2159
A further study of the alkaloid constituents of Aconitum forrestii led to the isolation of three new C19‐diterpenoid alkaloids, named 14‐acetoxy‐8‐O‐methylsachaconitine ( 1 ), 14‐acetoxyscaconine ( 2 ), and 8‐O‐ethylcammaconine ( 3 ). Their structures were determined by UV, IR, and MS, 1D‐ and 2D‐NMR analyses. 相似文献
135.
Ting‐Ting Zhang Xiao‐Xia Qi Jianfeng Jia Hai‐Shun Wu 《International journal of quantum chemistry》2013,113(7):1010-1017
Quantum chemistry methods are applied to investigate the electronic structures, injection and transport properties, absorption and phosphorescence mechanism of a series of Iridium (III) complexes [Ir(C∧N)2(L)2]+ (L = 4‐pyCO2Et; C∧N = 2‐phenylpyridine, 1 ; 2‐(4‐tolyl)pyridine, 2 ; 2‐(4,6‐difluorophenyl)pyridimato, 3 ; benzoquinoline, 4 ), which may be used as emitters on organic light emitting diodes (OLEDs). Calculations of ionization potentials and electron affinities are used to evaluate the injection abilities of holes and electrons into these complexes. The reorganization energy (λ) calculations show that the four complexes are suitable as emitters in OLEDs. The absorptions and emissions can be tuned by adding substituent to the ppy ligand or extending the π‐conjugation effect of the C∧N ligand, and quantum yields of 1 – 4 are investigated. In addition, no solvent effect is observed in the absorption and emission spectra. © 2012 Wiley Periodicals, Inc. 相似文献
136.
We have developed a simple and efficient method for dispersive liquid-liquid microextraction of 4-nitrophenol, 2-naphthol and bisphenol A in real water samples. It is making use of solidified floating organic droplets of 1-dodecanol which has low density and a proper melting point. The type and volume of extraction solvent and dispersive solvent, the effect of salts, pH value and extraction time were optimized and resulted in enrichment factors of 84 for 4-nitrophenol, 123 for 2-naphthol, and 97 for bisphenol A. The limits of detection by HPLC are 1.50, 0.10 and 1.02 ng · mL?1, respectively. Excellent linearity is observed in the concentration range from 10 to 800 ng · mL?1, with coefficients of correlation ranging from 0.9988 to 0.9999. The relative standard deviations (for n?=?5) are from 3.2 to 5.3 %, and relative recoveries for the three phenols in tap, river and spring water range from 85.0 to 105.0 %, 98.3 to 110.0 %, and 98.6 to 109.0 %, respectively. Figure
Chromatograms of river water blank (b) and spiked river water (a, 500 ng ? mL?1) analyzed with DLLME-SFO-HPLC. Peak identification: (1) p-nitrophenol; (2) 2-naphthol; (3) bisphenol A. Liquid-liquid microextraction method based on solidification of floating organic droplet (DLLME-SFO) has a high enrichment factor (84, 123and 97), acceptable relative recovery (85.0 %–110.0 %), good repeatability (5.27 %, 3.54 % and 3.16 %) and a wide linear range (10–800 ng · mL?1) for the determination of p-nitrophenol, 2-naphthol and bisphenol A. 相似文献
137.
We describe a rapid and convenient colorimetric method for the detection of oxidative DNA damage caused by peroxynitrite (ONOO?) using unmodified gold nanoparticles (AuNPs). AuNPs are stable in the presence of single-stranded DNA (ssDNA) against the aggregation induced by a high ionic strength. If adsorbed ssDNA are cleaved by ONOO? to form smaller fragments, the AuNPs rapidly aggregate due to electrostatic attraction. As a result, the color of the solution changes from red to blue, and this can be seen with bare eyes. We also have evaluated the activity of the antioxidants gallic acid, ascorbic acid and caffeic acid to scavenge ONOO?. This method therefore also can be applied to screen for anti-oxidation drugs and agents. Figure
ONOO?-induced ssDNA cleavage can be visually detected by a red-to-blue color change of AuNPs. 相似文献
138.
Shanshan Zhu Ning Gan Daodong Pan Yi Li Ting Yang Futao Hu Yuting Cao Dazhen Wu 《Mikrochimica acta》2013,180(7-8):545-553
We have prepared core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT). The use of particles strongly improves the imprinting effect and leads to fast adsorption kinetics and high adsorption capacities. The functional monomer acrylamide was grafted to the surface of Fe3O4 nanospheres in two steps, and MIP layers were then formed on the surface by creating a MIP layer on the surface consisting of poly(ethyleneglycol dimethacrylate) with a TBT template. The particles were characterized in terms of morphological, magnetic, adsorption, and recognition properties. We then have developed a method for the extraction of TBT from spiked mussel (Mytilidae), and its determination by liquid chromatography-tandem mass spectrometry. The method has a limit of detection of 1.0 ng?g?1 (n?=?5) of TBT, with a linear response between 5.0 and 1,000 ng?g?1. The proposed method was successfully applied to the determination of trace TBT in marine food samples with recoveries in the range of 78.3–95.6 %. Figure
The preparation procedures of core-shell magnetic molecularly imprinted polymer nanoparticles for recognition and extraction of tributyl tin (TBT) in seafood 相似文献
139.
A general and practical one‐pot synthesis of naphthopyran derivatives using hexadecyltrimethylammonium bromide (HTMAB) as catalyst (10 mol%) is described. This method provides several advantages such as neutral conditions, high yields and simple workup procedure. The catalyst is low cost, facile, active, environmentally friendly, and reusable. In addition, water is chosen as a green solvent. 相似文献
140.
Two indole-containing fullerene derivatives, N-hydrogen-2-[3-(N-2-ethylhexylindolyl)][60]fulleropyrrolidine (EHIHC60P), and N-(2-ethylhexylindolyl))-2-[3-(N-2-ethylhexylindolyl)][60]fulleropyrrolidine (DEHIC60P) were synthesized by the typical Prato reaction. The absorption spectra, electrochemical properties of the two compounds were measured. Inverted solar cells were fabricated with the structure of ITO/ZnO/poly(3-hexylthiophene) (P3HT):fullerene derivatives/MoO3/Ag. The highest power conversion efficiencies (PCEs) of 3.32% and 3.23% were obtained for P3HT/EHIHC60P and P3HT/DEHIC60P based solar cells at the composite ratio of 1:1 after the active layers were annealed at 150 °C under inert atmosphere, with a open-circuit voltage (Voc) of 0.66 V and 0.74 V, respectively. For comparison, the device based on P3HT/PCBM at the same conditions showed the PCE of 3.28%, with a Voc of 0.61 V. The influence on the photovoltaic property of the fullerene derivatives, which was induced by some subtle changes in the chemical structure was compared and discussed. 相似文献