共查询到20条相似文献,搜索用时 531 毫秒
1.
Xiao‐Xi Hu Peng‐Hui Li Kelvin W. K. Yeung Paul K. Chu Shui‐Lin Wu Zu‐Shun Xu 《Journal of polymer science. Part A, Polymer chemistry》2010,48(24):5961-5967
A complex of Eu3+, acrylic acid (AA), and 1, 10‐phenanthroline (Phen) was synthesized. The structure and fluorescence of Eu(AA)3Phen was characterized with elemental analysis, FTIR, 1H NMR, and fluorescence spectroscopy. A novel copolymer containing rare earth complex, poly(PEGMA‐co‐NIPAm‐co‐Eu(AA)3Phen) (PPNEu), was prepared by free radical copolymerization in methanol with azodiisobutyronitrile as initiator. 1H NMR, fluorescence spectroscopy, UV‐vis spectroscopy, and TEM were used to characterize this copolymer. The interaction of PPNEu with deoxyribonucleic acid (DNA) was studied by fluorescence spectroscopy, UV‐vis spectroscopy and agarose gel electrophoresis. The results of fluorescence, UV‐vis absorption, and agarose electrophoresis indicated that the PPNEu could interact with DNA in an electrostatic bonding mode. The TEM observation showed that the PPNEu could form spherical micelles in water solution small than 100 nm; the efficient complexation of PPNEu with DNA occurred. These results suggested the potential of the PPNEu as gene detective reagent and gene delivery carrier. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
2.
Penghui Li Xiaoxi Hu Shuilin Wu Paul K. Chu Kelvin W.K. Yeung Zushun Xu 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(10):832-839
Polymerizable rare earth complex Eu(AA)3Phen was synthesized by complexion of europium ion, acrylic acid (AA), and 1,10-phenanthroline (Phen). The structure and fluorescence properties of the complex were studied by elemental analysis, 1H-NMR spectroscopy, and fluorescence spectroscopy. Eu-containing copolymer poly(PEGMA-co-MMA-co-METAC-co-Eu(AA)3Phen) (PPMMEu) was then synthesized by free radical copolymerization of Eu(AA)3Phen and other functional monomers including poly(ethylene glycol) methyl ether methacrylate (PEGMA) and [2-(Methacryloyloxy) ethyl] trimethylammonium chloride (METAC). 1H-NMR spectroscopy and fluorescence spectroscopy were used to characterize the copolymer and the interactions between the copolymer and DNA was investigated by TEM, fluorescence spectroscopy, and agarose gel electrophoresis. The desired luminescent cationic copolymer was successfully obtained. The copolymer can form micelles in water solution and can efficiently bind to DNA molecules through electrostatic interaction. The results suggest the potential use of PPMMEu in bioprobes and gene vectors. 相似文献
3.
利用菲咯啉酮衍生物4-氯-2-(1H-咪唑并[4,5-f][1,10]菲咯啉)苯酚(HL)设计合成了一种新的单核铜配合物[Cu(L)(5-Cl-sal)(DMF)]ClO_4·DMF(5-Cl-Hsal=5-氯-水杨醛),用元素分析和X射线单晶衍射等手段对配合物进行了表征。该配合物晶体属三斜晶系,P1空间群。用紫外吸收光谱、荧光光谱和凝胶电泳等方法研究了配合物与DNA的相互作用。结果表明,配合物以插入方式与CT-DNA结合,结合常数为1.02×10~3 L·mol~(-1)。同时配合物也能较大程度淬灭EB-DNA复合物的荧光,表观键合常数为4.37×10~5L·mol_(-1),略小于经典键合常数107 L·mol~(-1)。淬灭机理为动态淬灭。凝胶电泳实验研究表明配合物在H_2O_2存在下可将pBR322质粒DNA切割为开环缺口型DNA和线型DNA,配合物浓度越大,切割效果越好。机理研究显示,配合物切割DNA的反应是由羟基自由基(·OH)和单线态氧(~1O_2)作为活性物种的氧化切割过程。 相似文献
4.
Amphiphilic fluorescent graft copolymer (PVP‐PyATAm) was successfully synthesized by the free radical copolymerizations of hydrophobic monomer N‐acryloyl‐thioureylene‐4‐(1‐pyrene)‐butyryl amide (PyATAm) with hydrophilic precursor polymers of vinyl‐functionalized poly (N‐vinylpyrrolidone) (Acryloyl‐PVP) in DMF. FT‐IR, 1H NMR, TEM, gel permeation chromatography‐multi‐angle laser light scattering, UV‐vis spectroscopy, viscometric measurement, and fluorescence spectroscopy were used to characterize this copolymer. The TEM observation showed that the copolymer PVP‐ PyATAm formed spherical micelles in an aqueous solution and the size of micelles was between 50 and 70 nm in diameter. The interaction of PVP‐PyATAm copolymer and plasmid DNA was examined by agarose gel electrophoresis and TEM. Results indicated that the copolymer–DNA complexes were self‐assembled and the size of complexes was between 90 and 120 nm in diameter. Cytotoxity studies using MTT colorimetric assays suggested good biocompatibility of PVP‐PyATAm in vitro. These results suggested the potential of this graft copolymer as gene delivery carrier. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献
5.
CeO2 nanoparticles approximately 12 nm in size were synthesized and subsequently characterized by XRD, TEM and UV-vis spectroscopy.
Then, a gold electrode modified with CeO2 nanoparticles was constructed and characterized by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV).
The modified electrode demonstrated strong catalytic effects with high stability towards electrochemical oxidation of rutin.
The anodic peak currents (measured by differential pulse voltammetry) increased linearly with the concentration of rutin in
the range of 5.0 × 10−7–5.0 × 10−4 mol · L−1. The detection limit (S/N = 3) was 2.0 × 10−7 mol · L−1. The relative standard deviation (RSD) of 8 successive scans was 3.7% for 5.0 × 10−6 mol · L−1 rutin. The method showed excellent sensitivity and stability, and the determination of rutin in tablets was satisfactory. 相似文献
6.
A novel hydrogen peroxide (H2O2) biosensor was developed by immobilizing hemoglobin on the gold colloid modified electrochemical pretreated glassy carbon
electrode (PGCE) via the bridging of an ethylenediamine monolayer. This biosensor was characterized by UV-vis reflection spectroscopy
(UV-vis), electrochemical impendence spectroscopy (EIS) and cyclic voltammetry (CV). The immobilized Hb exhibited excellent
electrocatalytic activity for hydrogen peroxide. The Michaelis–Menten constant (K
m) was 3.6 mM. The currents were proportional to the H2O2 concentration from 2.6 × 10−7 to 7.0 × 10−3 M, and the detection limit was as low as 1.0 × 10−7 M (S/N = 3). 相似文献
7.
利用菲咯啉酮衍生物4-氯-2-(1H-咪唑并[4,5-f][1,10]菲咯啉)苯酚(HL)设计合成了一种新的单核铜配合物[Cu (L)(5-Cl-sal)(DMF)]ClO4·DMF (5-Cl-Hsal=5-氯-水杨醛),用元素分析和X射线单晶衍射等手段对配合物进行了表征。该配合物晶体属三斜晶系,P1空间群。用紫外吸收光谱、荧光光谱和凝胶电泳等方法研究了配合物与DNA的相互作用。结果表明,配合物以插入方式与CT-DNA结合,结合常数为1.02×103 L·mol-1。同时配合物也能较大程度淬灭EB-DNA复合物的荧光,表观键合常数为4.37×105 L·mol-1,略小于经典键合常数107 L·mol-1。淬灭机理为动态淬灭。凝胶电泳实验研究表明配合物在H2O2存在下可将pBR322质粒DNA切割为开环缺口型DNA和线型DNA,配合物浓度越大,切割效果越好。机理研究显示,配合物切割DNA的反应是由羟基自由基(·OH)和单线态氧(1O2)作为活性物种的氧化切割过程。 相似文献
8.
Summary. Two novel Er-Cr ion-pair complexes ([Er(DMA)3(H2O)4][Cr(CN)6] and [Er(MPL)4(H2O)3][Cr(CN)6]·2H2O; DMA = dimethylacetamide, MPL = 1-methyl-2-pyrrolidinone) have been synthesized. [Er(DMA)3(H2O)4][Cr(CN)6] crystallizes in the monoclinic system (space group P
c
) with a = 9.789(2), b = 11.263(2), c = 13.997(3)?, β = 105.66(3)°, V = 1485.9(5)?3, Z = 2; [Er(MPL)4(H2O)3][Cr(CN)6]·2H2O crystallizes in the monoclinic system (space group P21) with a = 9.447(2), b = 13.881(3), c = 14.673(3)?, β = 101.85(3), V = 1883.1(7)?3, Z = 2. X-Ray crystal diffraction analyses reveal that the two complexes form a hydrogen bonding network structure through the
CN group and H2O molecules. Variable temperature susceptibilities for the two complexes indicate that weak antiferromagnetic interactions
exist between cation and anion pairs through this hydrogen bonding network. 相似文献
9.
Micellar behavior of acrylamide– octylphenylpoly(oxyethylene) acrylate copolymer in aqueous solution
The copolymer of acrylamide and octylphenylpoly(oxyethylene) acrylate macromonomer (AM-C8PhEO7Ac) was synthesized and characterized by IR and NMR spectroscopy. The molecular weight of the copolymer was determined to
be 1.21 × 105 by static light scattering. The weight contents of AM and macromonomer were determined to be 67.8 and 32.2%, respectively,
by elemental analysis. The micellar behavior of the copolymer in aqueous solution was studied by UV spectroscopy and atomic
force microscopy (AFM). The molecules of AM-C8PhEO7Ac copolymer form monomolecular micelles in the concentration range 4 × 10−6 – 3 × 10−5 g/ml and polymolecular micelles at concentrations above 3 × 10−5 g/ml according to the UV analysis. The AFM images indicate that the monomolecular micelles are globular with diameters of
70 nm and have a narrow size distribution. The polymolecular micelles can be globular or cylindrical depending on the concentration,
and have a wide size distribution.
Received: 10 February 1999 Accepted in revised form: 28 June 1999 相似文献
10.
A doubly hydrophilic triblock copolymer poly(acrylic acid)-b-poly(ethylene glycol)-b-poly(acrylic acid) (PAA-b-PEO-b-PAA) with M
w/M
n = 1.15 was synthesized by atom transfer radical polymerization of t-butyl acrylate (tBA), followed by acidolysis of the PtBA blocks. The pH-sensitive micellization of PAA-b-PEO-b-PAA in acidic solution was investigated by potentiometric titration, fluorescence spectrum, dynamic light scattering and
zeta potential. The pK
a was 6.6 and 6.0 in deionized water and in 0.1 mol/L NaCl solution, respectively. The copolymer formed micelles composed of
a weakly hydrophobic core of complexed PAA and PEO and a hydrophilic PEO shell in 1 mg/mL solution at pH < 5.5 due to hydrogen
bonding. The critical micelle concentration was 0.168 mg/mL at pH 2.0. At pH < 4.5, steady and narrow distributed micelles
were formed. Increasing pH to 5.0, unsteady and broad distributed micelles were observed. At pH > 5.5, the micelle was destroyed
owing to the ionization of the PAA blocks. 相似文献
11.
Mussardo P Corda E González-Ruiz V Rajesh J Girotti S Martín MA Olives AI 《Analytical and bioanalytical chemistry》2011,400(2):321-327
The interaction between DNA and several newly synthesized derivatives of the natural anticancer compound luotonin A has been
studied. The results from our work reveal an effective and selective alkaloid/double-stranded DNA (ds-DNA) interaction. In
the presence of increasing amounts of ds-DNA, a noticeable fluorescence quenching of the luotonin A derivatives under study
was observed. However, this effect did not take place when single-stranded DNA (ss-DNA) was employed. The association constant
alkaloids/ds-DNA was calculated by quantitation of such a quenching effect. The influence of other quenchers, namely Co2+ and Br− on the native fluorescence of luotonin A and derivatives was also studied, and a remarkable quenching effect was observed
for both ions. We have also investigated how by binding DNA the alkaloids could get protected from the external Co2+ and Br− quenchers. The Stern–Volmer constants (K
SV) for Co2+ and Br− quenching effect on the studied alkaloids were considerably reduced (10–50%) after incubation of the compounds in the presence
of DNA with regard to the K
SV values in absence of DNA. An increase in the fluorescence anisotropy values of luotonins was also produced only in the presence
of ds-DNA but not in the case of ss-DNA. To better characterize the nature of that interaction, viscosimetry assays and ethidium
bromide displacement studies were conducted. With regard to DNA reference solutions, the viscosity of solutions containing
DNA and luotonin A derivatives was reduced or not significantly increased. It was also observed that the studied compounds
were unable to displace the intercalating agent ethidium bromide. All of these results, together with the obtained association
constants values (K
ass = 2.2 × 102 – 1.3 × 103), support that neither covalent nor intercalating interactions luotonin A derivatives/ds-DNA are produced, leading to the
conclusion that these alkaloids bind ds-DNA through the minor groove. The specific changes in the fluorescence behavior of
luotonin A and derivatives distinguishing between ss-DNA and ds-DNA binding, lead us to propose these compounds as attractive
turn-off probes to detect DNA hybridization. 相似文献
12.
合成并表征了2个不对称大环双核铜配合物[Cu2(L1)Cl2]·CH3CN(1)和[Cu2(L2)Br2]·CH3CN·H2O(2)。配合物与CT-DNA的作用通过紫外-可见光谱,粘度实验,圆二色谱和凝胶电泳实验进行了研究。紫外-可见光谱的结果表明配合物与DNA的结合常数分别为6.2×105和7.2×105,圆二色谱的实验表明配合物能与DNA较好的结合,粘度实验表明配合物与DNA的结合为非典型的插入模式,凝胶电泳实验显示配合物通过氧化机理对DNA有较强的切割活性。 相似文献
13.
Mayumi Kaneko Masanobu Nakayama Masataka Wakihara 《Journal of Solid State Electrochemistry》2007,11(8):1071-1076
This paper describes two kinds of elastomeric binders which are styrene–butadiene (ST–BD) copolymer and 2-ethylhexyl acrylate–acrylonitrile
(2EHA–AN) copolymer for electrode materials of rechargeable Li-ion batteries. These elastomeric binders were swollen by electrolyte
solution (EC/DEC=1/2, 1 M LiPF6), and 2EHA–AN copolymer retained larger amount of electrolyte solution than ST–BD copolymer. The Li-ionic conduction behavior
was investigated for both copolymer films swollen by electrolyte solution. The Li-ion conductivity of ST–BD copolymer was
9.45 × 10−8 S·cm−1 and that of 2EHA–AN copolymer was 1.25 × 10−5 S·cm−1 at room temperature, and the corresponding amounts of activation energy were 0.31 and 0.26 eV, respectively. Because the
observed activation energy in elastomeric binder was different from that in the bulk of electrolyte solution (0.09 eV), Li-ion
conduction of the bulk of elastomeric binder swollen by electrolyte was affected by the polymer structure of binders. Electrochemical
performance of cathode material, LiCoO2, was investigated with three kinds of binders: ST–BD copolymer, 2EHA–AN copolymer, and poly(vinylidene fluoride). The initial
charge–discharge capacity of the LiCoO2 electrode with 2EHA–AN copolymer showed highest capacity, suggesting that Li+-ion conduction inside of the elastomeric binder contributes to the enhancement of charging and discharging capacity. This
result indicates that elastomeric binder with sufficient Li-ionic conductivity can be an attractive candidate for improving
cathode of lithium-ion battery. 相似文献
14.
Hadi Beitollahi Mohammad Mazloum Ardakani Hossein Naeimi Bahram Ganjipour 《Journal of Solid State Electrochemistry》2009,13(3):353-363
The preparation and electrochemical characterization of a carbon nanotube paste electrode modified with 2,2′-[1,2-ethanediylbis
(nitriloethylidyne)]-bis-hydroquinone, referred to as EBNBH, was investigated. The EBNBH carbon nanotube paste electrode (EBNBHCNPE)
displayed one pair of reversible peaks at E
pa = 0.18 V and E
pc = 0.115 V vs Ag/AgCl. Half wave potential (E
1/2) and ΔE
p were 0.148 and 0.065 V vs Ag/AgCl, respectively. The electrocatalytic oxidation of ascorbic acid (AA) has been studied on
EBNBHCNPE, using cyclic voltammetry, differential pulse voltammetry and chronoamperometry techniques. It has been shown that
the oxidation of AA occurs at a potential where oxidation is not observed at the unmodified carbon paste electrode. The heterogeneous
rate constant for oxidation of AA at the EBNBHCNPE was also determined and found to be about 1.07 × 10−3 cm s−1. The diffusion coefficient of AA was also estimated as 5.66 × 10−6 cm2 s−1 for the experimental conditions, using chronoamperometry. Also, this modified electrode presented the property of electrocatalysing
the oxidation of AA and uric acid (UA) at 0.18 and 0.35 V vs Ag/AgCl, respectively. The separations of anodic peak potentials
of AA and UA reached 0.17 V. Using differential pulse voltammetry, the calibration curves for AA and UA were obtained over
the range of 0.1–800 μM and 20–700 μM, respectively. With good selectivity and sensitivity, the present method provides a
simple method for selective detection of AA and UA in biological samples. 相似文献
15.
16.
A new Ni(II) complex, namely [Ni2(OAc)L]·ClO4·H2O, was synthesized by [2 + 2] cyclo-condensation between 2,6-diformyl-4-methylphenol and N,N-bis(3-aminopropyl)-4-methoxybenzylamine (amba) in the presence of nickel(II) and characterized by spectroscopy, elemental
analysis, and X-ray single crystal diffraction. The interactions of the complex with DNA have been measured by spectroscopy
and viscosity measurements. Absorption spectroscopic investigation reveals intercalative binding of the Ni(II) complex with
DNA, with a binding constant of 2.6 × 104 M−1. Fluorescence spectroscopy shows that the Ni(II) complex can displace ethidium bromide and bind to DNA, with a quenching
constant of 7.57 × 103 M−1. The appearance of increased CD bands near 245 and 275 nm gives evidence for effective complex DNA binding. The agarose gel
electrophoresis studies show that the complex displays effective DNA cleavage activity in the absence of any external agents. 相似文献
17.
合成并表征了2个不对称大环双核铜配合物[Cu2(L1)Cl2]·CH3CN(1)和[Cu2(L2)Br2]·CH3CN·H2O(2)。配合物与CT-DNA的作用通过紫外-可见光谱,粘度实验,圆二色谱和凝胶电泳实验进行了研究。紫外-可见光谱的结果表明配合物与DNA的结合常数分别为6.2×105和7.2×105,圆二色谱的实验表明配合物能与DNA较好的结合,粘度实验表明配合物与DNA的结合为非典型的插入模式,凝胶电泳实验显示配合物通过氧化机理对DNA有较强的切割活性。 相似文献
18.
Eloi Feitosa Fernanda Rosa Alves Elisabete M. S. Castanheira M. Elisabete C. D. Real Oliveira 《Colloid and polymer science》2009,287(5):591-599
In the millimolar concentration domain (typically 1 mM), dioctadecyldimethylammonium bromide and chloride (DODAX, X representing
Br− or Cl− counterions) molecules assemble in water as large unilamellar vesicles. Differential-scanning calorimetry (DSC) is a suitable
technique to obtain the melting temperature (T
m) characteristic of surfactant bilayers, while fluorescence spectroscopy detects formation of surfactant aggregates, like
bilayers. These two techniques were combined to investigate the assembly of DODAX molecules at micromolar concentrations,
from 10 to 100 μM. At 1 mM surfactant, T
m ≈ 45 °C and 49 °C, respectively, for DODAB and DODAC. DSC and fluorescence of Nile Red were used to show the formation of
DODAX aggregates, at the surfactant concentration as low as 10 μM, whose T
m decreases monotonically with increasing DODAX concentration to attain the value for the ordinary vesicles. The data indicate
that these aggregates are organized as bilayer-like structures. 相似文献
19.
Jahan Bakhsh Raoof Abolfazl Kiani Reza Ojani Roudabeh Valiollahi Sahar Rashid-Nadimi 《Journal of Solid State Electrochemistry》2010,14(7):1171-1176
Gold nanoparticles (GNs) could be efficiently immobilized on binary mixed self-assembled monolayers (SAMs) on a gold surface
composed of 1,6-hexanedithiol and 1-octanethiol (nano-Au/SAMs gold electrode). This GN chemically modified electrode was used
for electrochemical determination of ascorbic acid (AA) and dopamine (DA) in aqueous media. The result showed that the GN-modified
electrode could clearly resolve the oxidation peaks of AA and DA, with a peak-to-peak separation (∆E
p) of 110 mV enabling determination of AA and DA in the presence of each other. The linear analytical curves were obtained
in the ranges of 0.3–1.4 mM for AA and 0.2–1.2 mM for DA concentrations using differential pulse voltammetry. The detection
limits (3σ) were 9.0 × 10−5 M for AA and 9.0 × 10−5 M for DA. 相似文献
20.
Summary. Single crystals of sodium dithiophosphate undecahydrate (Na3PO2S2 · 11H2O) and sodium trithiophosphate undecahydrate (Na3POS3 · 11H2O) were grown from aqueous solution. The crystal structures of Na3PO2S2 · 11H2O (P212121; a = 1248.1(1), b = 945.2(1), c = 1383.1(1) pm; R
1 = 0.0202, wR
2 = 0.0502) and Na3POS3 · 11H2O (Pna21; a = 1262.0(2), b = 947.6(2), c = 1431.5(2) pm; R
1 = 0.0720, wR
2 = 0.1371) are related to each other in a sense that all constituting units are arranged in similar positions and with similar
orientations. The geometries of the anions were determined with high accuracy; thus, the structural parameters of the POS3−
3 anion were measured for the first time.
Received September 25, 2001. Accepted January 21, 2002 相似文献