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1.
In this study, with the aim to enhance the ionic conduction of known structures by defect chemistry, the La2O3-Ta2O5 system was considered with a focus on the La3TaO7 phase whose structure is of Weberite type. In order to predict possible preferential substitution sites and substitution elements, atomistic simulation was used as a first approach. A solid solution La3−xSrxTaO7−x/2 was confirmed by X-ray diffraction and Raman spectroscopy; it extends for a substitution ratio up to x = 0.15. Whereas La3TaO7 is a poor oxide ion conductor (σ700 °C = 2 × 10−5S.cm−1), at 700 °C, its ionic conductivity is increased by more than one order of magnitude when 3.3% molar strontium is introduced in the structure (σ700 °C = 2 × 10−4S.cm−1).  相似文献   

2.
Titania-lanthanum phosphate nanocomposites with multifunctional properties have been synthesized by aqueous sol-gel method. The precursor sols with varying TiO2:LaPO4 ratios were applied as thin coating on glass substrates in order to be transparent, hydrophobic, photocatalytically active coatings. The phase compositions of the composite powders were identified by powder X-ray diffraction (XRD) and high-resolution transmission electron microscopy (HR-TEM). The anatase phase of TiO2 in TiO2-LaPO4 composite precursors was found to be stable even on annealing at 800 °C. The glass substrates, coated with TL1 (TiO2-LaPO4 composition with 1 mol% LaPO4) and TL50 (composite precursor containing TiO2 and LaPO4 with molar ratio 1:1) sols and annealed at 400 °C, produced contact angles of 74° and 92°, respectively, though it is only 62° for pure TiO2 coating. The glass substrates, coated with TL50 sol, produced surfaces with relatively high roughness and uneven morphology. The TL1 material, annealed at 800 °C, has shown the highest UV photoactivity with an apparent rate constant, kapp=24×10−3 min−1, which is over five times higher than that observed with standard Hombikat UV 100 (kapp=4×10−3 min−1). The photoactivity combined with a moderate contact angle (85.3°) shows that this material has a promise as an efficient self-cleaning precursor.  相似文献   

3.
Composite solid electrolytes in the system (1 − x)LiNO3-xAl2O3, with x = 0.0-0.5 were synthesized by sol-gel method. The synthesis carried out at low temperature resulted in voluminous and fluffy products. The obtained materials were characterized by X-ray diffraction, differential scanning calorimetry, scanning electron microscopy/energy dispersive X-ray, Fourier transform infrared spectroscopy and AC impedance spectroscopy. Structural analysis of the samples showed base centred cell type of point lattice of LiNO3 for the composite samples with x = 0.1-0.2 and body centred cell for the sample with x = 0.3. A trace amount of α-LiAlO2 crystal phase was also present in these composite samples. The thermal analysis showed that the samples were in a stable phase between 48 °C and 230-260 °C. Morphological analysis indicated the presence of amorphous phase and particles with sizes ranging from micro to nanometre scale for the composite sample with x = 0.1. The conductivities of the composites were in the order of 10−3 and 10−2 S cm−1 at room temperature and 150 °C, respectively.  相似文献   

4.
Oriented films of cellulose prepared from algal cellulose were hydrothermally treated to convert them into highly crystalline cellulose Iβ. The lateral thermal expansion behavior of the prepared cellulose Iβ films was investigated using X-ray diffraction at temperatures from 20 to 300 °C. Cellulose Iβ was transformed into the high-temperature phase when the temperature was above 230 °C, allowing the lateral thermal expansion coefficient of cellulose Iβ and its high-temperature phase to be measured. For cellulose Iβ, the thermal expansion coefficients (TECs) of the a- and b-axes were αa = 9.8 × 10−5 °C−1 and αb = 1.2 × 10−5 °C−1, respectively. This anisotropic thermal expansion behavior in the lateral direction is ascribed to the crystal structure and to the hydrogen-bonding system of cellulose Iβ. For the high-temperature phase, the anisotropy was more conspicuous, and the TECs of the a- and b-axes were αa = 19.8 × 10−5 °C−1 and αb = −1.6 × 10−5 °C−1, respectively. Synchrotron X-ray fiber diffraction diagrams of the high-temperature phase were also recorded at 250 °C. The cellulose high-temperature phase is composed of a two-chain monoclinic unit cell, a = 0.819 nm, b = 0.818 nm, c (fiber repeat) = 1.037 nm, and γ = 96.4°, with space group = P21. The volume of this cell is 4.6% larger than that of cellulose Iβ at 30 °C.  相似文献   

5.
Specific heat capacities (Cp) of polycrystalline samples of BaCeO3 and BaZrO3 have been measured from about 1.6 K up to room temperature by means of adiabatic calorimetry. We provide corrected experimental data for the heat capacity of BaCeO3 in the range T < 10 K and, for the first time, contribute experimental data below 53 K for BaZrO3. Applying Debye's T3-law for T → 0 K, thermodynamic functions as molar entropy and enthalpy are derived by integration. We obtain Cp = 114.8 (±1.0) J mol−1 K−1, S° = 145.8 (±0.7) J mol−1 K−1 for BaCeO3 and Cp = 107.0 (±1.0) J mol−1 K−1, S° = 125.5 (±0.6) J mol−1 K−1 for BaZrO3 at 298.15 K. These results are in overall agreement with previously reported studies but slightly deviating, in both cases. Evaluations of Cp(T) yield Debye temperatures and identify deviations from the simple Debye-theory due to extra vibrational modes as well as anharmonicity. The anharmonicity turns out to be more pronounced at elevated temperatures for BaCeO3. The characteristic Debye temperatures determined at T = 0 K are Θ0 = 365 (±6) K for BaCeO3 and Θ0 = 402 (±9) K for BaZrO3.  相似文献   

6.
Isothermal crystallization of poly(3-hydroxybutyrate-co-3-hydroxyvalerate)   总被引:1,自引:0,他引:1  
Isothermal crystallization behavior of poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was investigated by means of differential scanning calorimetry and polarized optical microscopy (POM). The Avrami analysis can be used successfully to describe the isothermal crystallization kinetics of PHBV, which indicates that the Avrami exponent n=3 is good for all the temperatures investigated. The spherulitic growth rate, G, was determined by POM. The result shows that the G has a maximum value at about 353 K. Using the equilibrium melting temperature (448 K) determined by the Flory equation for melting point depression together with U∗=1500 cal mol−1, T=30 K and Tg=278 K, the nucleation parameter Kg was determined, which was found to be 3.14 ± 0.07 × 105 (K2), lower than that for pure PHB. The surface-free energy σ=2.55×10−2 J m−2 and σe=2.70±0.06×10−2 J m−2 were estimated and the work of chain-folding (q=12.5±0.2 kJ mol−1) was derived from σe, and found to be lower than that for PHB. This implies that the chains of PHBV are more flexible than that of PHB.  相似文献   

7.
Heat capacity and enthalpy increments of ternary bismuth tantalum oxides Bi4Ta2O11, Bi7Ta3O18 and Bi3TaO7 were measured by the relaxation time method (2-280 K), DSC (265-353 K) and drop calorimetry (622-1322 K). Temperature dependencies of the molar heat capacity in the form Cpm=445.8+0.005451T−7.489×106/T2 J K−1 mol−1, Cpm=699.0+0.05276T−9.956×106/T2 J K−1 mol−1 and Cpm=251.6+0.06705T−3.237×106/T2 J K−1 mol−1 for Bi3TaO7, Bi4Ta2O11 and for Bi7Ta3O18, respectively, were derived by the least-squares method from the experimental data. The molar entropies at 298.15 K, S°m(298.15 K)=449.6±2.3 J K−1 mol−1 for Bi4Ta2O11, S°m(298.15 K)=743.0±3.8 J K−1 mol−1 for Bi7Ta3O18 and S°m(298.15 K)=304.3±1.6 J K−1 mol−1 for Bi3TaO7, were evaluated from the low-temperature heat capacity measurements.  相似文献   

8.
The ternary rare-earth metal boride carbides RE15B6C20 (RE=Pr, Nd) were synthesized by co-melting the elements. They exist above 1270 K. Their crystal structures were determined from single-crystal X-ray diffraction data. Both crystallize in the space group P1¯, Z=1, a=8.3431(8) Å, b=9.2492(9) Å, c=8.3581(8) Å, α=84.72(1)°, β=89.68(1)°, γ =84.23(1)° (R1=0.041 (wR2=0.10) for 3291 reflections with Io>2σ(Io)) for Pr15B6C20, and a=8.284(1) Å, b=9.228(1) Å, c=8.309(1) Å, α=84.74(1)°, β=89.68(1)°, γ=84.17(2)° (R1=0.033 (wR2=0.049) for 2970 reflections with Io>2σ(Io)) for Nd15B6C20. Their structure consists of a three-dimensional framework of rare-earth metal atoms resulting from the stacking of slightly corrugated and distorted square nets, leading to cavities filled with unprecedented B2C4 finite chains, disordered C3 entities and isolated carbon atoms, respectively. Structural and theoretical analyses suggest the ionic formulation (RE3+)15([B2C4]6−)3([C3]4−)2(C4−)2·11ē. Accordingly, density functional theory calculations indicate that the compounds are metallic. Both structural arguments as well as energy calculations on different boron vs. carbon distributions in the B2C4 chains support the presence of a CBCCBC unit. Pr15B6C18 exhibits antiferromagnetic order at TN=7.9 K, followed by a meta-magnetic transition above a critical external field B>0.03 T. On the other hand, Nd15B6C18 is a ferromagnet below TC≈40 K.  相似文献   

9.
A straight forward room-temperature synthesis of V(III) containing complex fluoride K3VF6, using KF and vanadium(III) acetylacetonate is reported. The pale green colored powder was characterized by chemical analysis, powder X-ray diffraction; diffuse reflectance spectroscopy, infrared spectroscopy, Raman spectroscopy, differential scanning calorimetry, scanning electron microscopy, photoluminescence spectroscopy, magnetic susceptibility measurements and photoluminescence spectroscopy. The powder X-ray diffraction pattern was fitted in P21/n space group (monoclinic) with a = 12.106 (1) Å, b = 17.685 (0) Å, c = 11.802 (0) Å, β = 92.23° (1). Differential scanning calorimetry showed phase transitions, occurring at 158 °C and 190 °C. In the FT-IR spectrum, characteristic band for the VF63− group was observed at 508 cm−1. The bands observed in the 335-361 cm−1 region and at 504 cm−1 in the room temperature Raman spectrum of K3VF6 corresponded to the F2g and A1g modes, respectively. The ratio of the frequencies (F2g/A1g) observed in the diffuse reflectance spectrum was fitted on the Tanabe-Sugano diagram to determine the Racah parameter B value of 712 cm−1. Magnetic ordering was not observed down to the lowest measured temperature of 5 K.  相似文献   

10.
The hydrogen peroxide-oxidation of o-phenylenediamine (OPD) catalyzed by horseradish peroxidase (HRP) at 37 °C in 50 mM phosphate buffer (pH 7.0) was studied by calorimetry. The apparent molar reaction enthalpy with respect to OPD and hydrogen peroxide were −447 ± 8 kJ mol−1 and −298 ± 9 kJ mol−1, respectively. Oxidation of OPD by H2O2 catalyzed by HRP (1.25 nM) at pH 7.0 and 37 °C follows a ping-pong mechanism. The maximum rate Vmax (0.91 ± 0.05 μM s−1), Michaelis constant for OPD Km,S (51 ± 3 μM), Michaelis constant for hydrogen peroxide Km,H2O2 (136 ± 8 μM), the catalytic constant kcat (364 ± 18 s−1) and the second-order rate constants k+1 = (2.7 ± 0.3) × 106 M−1 s−1 and k+5 = (7.1 ± 0.8) × 106 M−1 s−1 were obtained by the initial rate method.  相似文献   

11.
A novel and sensitive electrochemical DNA biosensor has been developed for the detection of DNA hybridization. The biosensor was proposed by using copper(II) complex of Luteolin C30H18CuO12 (CuL2) as an electroactive indicator based on silver nanoparticles and multi-walled carbon nanotubes (Ag/MWCNTs) modified glassy carbon electrode (GCE). In this method, the 4-aminobenzoic acid (4-ABA) and Ag nanoparticles were covalently grafted on MWCNTs to form Ag/4-ABA/MWCNTs. The proposed method dramatically increased DNA attachment quantity and complementary ssDNA detection sensitivity for its large surface area and good charge-transport characteristics. DNA hybridization detection was performed using CuL2 as an electroactive indicator. The CuL2 was synthesized and characterized using elemental analysis (EA) and IR spectroscopy. Cyclic voltammetry (CV) and fluorescence spectroscopy were used to investigate the interaction between CuL2 and ds-oligonucleotides (dsDNA). It was revealed that CuL2 presented high electrochemical activity on GCE, and it could be intercalated into the double helices of dsDNA. The target ssDNA of the human hepatitis B virus (HBV) was quantified in a linear range from 3.23 × 10−12 to 5.31 × 10−9 M (r = 0.9983). A detection limit of 6.46 × 10−13 M (3σ, n = 11) was achieved.  相似文献   

12.
The kinetics of the radical reactions of CH3 with HCl or DCl and CD3 with HCl or DCl have been investigated in a temperature controlled tubular reactor coupled to a photoionization mass spectrometer. The CH3 (or CD3) radical, R, was produced homogeneously in the reactor by a pulsed 193 nm exciplex laser photolysis of CH3COCH3 (or CD3COCD3). The decay of CH3/CD3 was monitored as a function of HCl/DCl concentration under pseudo-first-order conditions to determine the rate constants as a function of temperature, typically from 188 to 500 K. The rate constants of the CH3 and CD3 reactions with HCl had strong non-Arrhenius behavior at low temperatures. The rate constants were fitted to a modified Arrhenius expression k = QA exp (−Ea/RT) (error limits stated are 1σ + Students t values, units in cm3 molecule−1 s−1): k(CH3 + HCl) = [1.004 + 85.64 exp (−0.02438 × T/K)] × (3.3 ± 1.3) × 10−13 exp [−(4.8 ± 0.6) kJ mol−1/RT] and k(CD3 + HCl) = [1.002 + 73.31 exp (−0.02505 × T/K)] × (2.7 ± 1.2) × 10−13 exp [−(3.5 ± 0.5) kJ mol−1/RT]. The radical reactions with DCl were studied separately over a wide ranges of temperatures and in these temperature ranges the rate constants determined were fitted to a conventional Arrhenius expression k = A exp (−Ea/RT) (error limits stated are 1σ + Students t values, units in cm3 molecule−1 s−1): k(CH3 + DCl) = (2.4 ± 1.6) × 10−13 exp [−(7.8 ± 1.4) kJ mol−1/RT] and k(CD3 + DCl) = (1.2 ± 0.4) × 10−13 exp [−(5.2 ± 0.2) kJ mol−1/RT] cm3 molecule−1 s−1.  相似文献   

13.
New ternary rare-earth metal boride carbides RE25B14C26 (RE=Pr, Nd) and Nd25B12C28 were synthesized by co-melting the elements. Nd25B12C28 is stable up to 1440 K. RE25B14C26 (RE=Pr, Nd) exist above 1270 K. The crystal structures were investigated by means of single-crystal X-ray diffraction. Nd25B12C28: space group P, a=8.3209(7) Å, b=8.3231(6) Å, c=29.888(2) Å, α=83.730(9)°, β=83.294(9)°, γ=89.764(9)°. Pr25B14C26: space group P21/c, a=8.4243(5) Å, b=8.4095(6) Å, c=30.828(1) Å, β=105.879(4)°, V=2100.6(2) Å3, (R1=0.048 (wR2=0.088) from 2961 reflections with Io>2σ(Io)); for Nd25B14C26 space group P21/c, Z=2, a=8.3404(6) Å, b=8.3096(6) Å, c=30.599(2) Å, β=106.065(1)°. Their structures consist of a three-dimensional framework of rare-earth metal atoms resulting from the stacking of slightly corrugated and distorted square nets, leading to cavities filled with cumulene-like molecules [B2C4]6− and [B3C3]7−, nearly linear [BC2]5− and bent [BC2]7− units and isolated carbon atoms. Structural and theoretical analysis suggests the ionic formulation for RE25B14C26: (RE3+)25[B2C4]6−([B3C3]7−)2([BC2]5−)4([BC2]7−)2(C4−)4·5e and for Nd25B12C28: (Nd3+)25([B2C4]6−)3([BC2]5−)4([BC2]7−)2(C4−)4·7e. Accordingly, extended Hückel tight-binding calculations indicate that the compounds are metallic in character.  相似文献   

14.
Chemometric analysis of ultraviolet-visible (UV-vis) spectra for pH values 1.0, 3.3, 5.3, and 6.9 was used to investigate the kinetics and the structural transformations of anthocyanins in extracts of calyces of hibiscus flowers of the Hibiscus acetosella Welw. ex Finicius for the first time. Six different species were detected: the quinoidal base (A), the flavylium cation (AH+), the pseudobase or carbinol pseudobase (B), cis-chalcone (CC), trans-chalcone (Ct), and ionized cis-chalcone (CC). Four equilibrium constant values were calculated using relative concentrations, hydration, pKh = 2.60 ± 0.01, tautomeric, KT = 0.14 ± 0.01, acid-base, pKa = 4.24 ± 0.04, and ionization of the cis-chalcone, pKCC=8.74±1.5×10−2. The calculated protonation rate of the tautomers is KH+=0.08±7.6×10−3. These constants are in excellent agreement with those measured previously in salt form. From a kinetic viewpoint, the situation encountered is interesting since the reported investigation is limited to visible light absorption in acid medium. These models have not been reported in the literature.  相似文献   

15.
A single-crystal X-ray diffraction analysis has been performed on KDyP4O12 synthesized by a flux method. The new compound crystallizes at room temperature in the monoclinic space group C2/c with unit cell parameters: a=7.812(2) Å, b=12.318(3) Å, c=10.441(2) Å, β=111.09(2)°, V=937.42(4) Å3 and Dcal=3.66 g cm−3 for Z=4. A full-matrix least square refinement gave R1=0.022, wR2=0.04 for 2421 independent reflections (I>2σ(I)) refined with 84 parameters.The structure is built up from P4O124− cyclotetraphosphate anions linked by DyO8 polyhedra to form a three-dimensional framework, which delimits intersecting oxygen tunnels in which the K+ ions are located. The atomic arrangement can be described as a succession of layers extending along the [010] direction. The P4O124− ring anion is centrosymmetrical is connected by irregularly shaped KO10 polyhedra to form a layer structure parallel to (001). Dysprosium and potassium are surrounded by eight and ten oxygen atoms respectively.Samples have been examined by impedance and infrared spectroscopy techniques. The reported IR absorption investigation, recorded at room temperature in the frequency range 200-4000 cm−1, shows some bands characteristic of cyclotetraphosphates.The electrical conductivity of KDyP4O12 has subsequently been measured as a function of temperature, it represents a significant ionic conductivity and activation energy (σ=2.15×10−4 Ω−1cm−1 at 453 K and Ea=0.387 eV) corresponding to the mobility of the K+ cations located within tunnels.  相似文献   

16.
In this study we present results of the conductivity and resistance to thermooxidative and condensation reactions of a highly phosphonated poly(pentafluorostyrene) (PWN2010) and of its blends with poly(benzimidazole)s (PBI). This polymer, which combines both: (i) a high degree of phosphonation (above 90%) and (ii) a relatively high acidity (pKa (–PO3H2 ↔ –PO3H) ∼ 0.5) due to the fluorine neighbors, is designed for low humidity operating fuel cell. This was confirmed by the conductivity measurements for PWN2010 reaching σ = 5 × 10−4 S cm−1 at 150 °C in dry N2 and σ = 1 × 10−3 S cm−1 at 150 °C (λ = 0.75). Furthermore, this polymer showed only 48% of anhydride formation when annealing it at T = 250 °C for 5 h and only 2% weight loss during a 96 h Fenton test. These properties combined with the ability of the PWN2010 to form homogeneous blends with polybenzimidazoles resulting in stable and flexible polymer films, makes PWN2010 a very promising candidate as a polymer electrolyte for intermediate- and high-temperature fuel cell applications.  相似文献   

17.
Single crystals of a new compound, BaBi2B4O10 were grown by cooling a melt with the stoichiometric composition. The crystal structure of the compound has been solved by direct methods and refined to R1=0.049 (wR=0.113) on the basis of 1813 unique observed reflections (|Fo|>4σ|Fo|). It is monoclinic, space group P21/c, a=10.150(2), b=6. 362(1), c=12.485(2) Å, β=102.87(1)o, V=786.0(2) Å3, Z=4. The structure is based upon anionic thick layers that are parallel to (001). The layers can be described as built from alternating novel borate [B4O10]8− chains and bismuthate [Bi2O5]4− chains extended along b-axis. The borate chains are composed of [B3O8]7− triborate groups of three tetrahedra and single triangles with a [BO2] radical. The borate chains are interleaved along the c-axis with rows of the Ba2+ cations so that the Ba atoms are located within the layers. The layers are connected by two nonequivalent Ba-O bonds as well as by two equivalent Bi-O bonds with bond valences in the range of 0.2-0.3 v.u.Thermal expansion of BaBi2B4O10 studied by high-temperature X-ray powder diffraction in the temperature range of 20-700 °C (temperature step 30-35 °C) is highly anisotropic. While the b and c unit-cell parameters increase almost linearly on heating, temperature dependencies of a parameter and β monoclinic angle show nonlinear behavior. As a result, on heating orientation of thermal expansion tensor changes, and bulk thermal expansion increases from 20×10−6 °C−1 at the first heating stage up to 57×10−6 °C−1 at 700 °C that can be attributed to the increase of thermal mobility of heavy Bi3+ and Ba2+ cations.  相似文献   

18.
The complex [(IMesH2)(PPh2Cy)Cl2RuCHPh] was synthesised and shown to be an active catalyst in ring-closing metathesis of a diallylmalonate. Its phosphine exchange was investigated in C6D6 using magnetisation transfer 31P NMR spectroscopy and it was found to operate via a dissociative mechanism with k353 = 4.1 ± 0.9 s−1, ΔH = 84 ± 10 kJ mol−1 and ΔS = 4 ± 28 J mol−1 K−1.  相似文献   

19.
Palladium(II) complexes with a tetradentate pseudo-tripodal ligand having two phosphino groups and two phosphine sulfide or selenide groups, pp3X2 (pp3 = tris[2-(diphenylphosphino)ethyl]phosphine, X = S (1) or Se (2)), were prepared from [PdCl(pp3)]Cl. Both of these phosphine chalcogenide complexes 1 and 2 showed rapid equilibrium between the five-coordinate [PdCl(pp3X2)]Cl with two bound phosphine chalcogenide groups and four-coordinate [PdCl2(pp3X2)] with two dissociated pendant ones in chloroform. The thermodynamic parameters for the reaction, [PdCl(pp3X2)]+ + Cl?[PdCl2(pp3X2)], were obtained by low-temperature 31P NMR as follows: K298 = 3.7 × 103 and 5.4 × 102 mol−1, ΔH° = 11.3 ± 0.3 and 13.4 ± 0.4 kJ mol−1, and ΔS° = 106 ± 2 and 97 ± 2 J mol−1 K−1 for 1 and 2, respectively. The rate for the geometrical change at 246.7 K for 1 was appreciably faster than that for 2. These thermodynamic and kinetic results indicate that the phosphine selenide Se atoms can stabilize the five-coordinate structure by effective π-back donation from Pd(II) compared with the phosphine sulfide S atoms. Difference in retention of the catalytic activity for Suzuki coupling, 2 > 1 > [PdCl(pp3 or p3)]Cl, was explained by difference in the π-accepting ability that stabilizes the catalytically active Pd(0) species. Considering the rapid dissociation-coordination equilibrium of the phosphine chalcogenide groups on Pd(II), it is probable that the oxidative addition and the subsequent transmetallation of the Pd(II) species are hardly blocked by the phosphine chalcogenide groups.  相似文献   

20.
Jia D  Dai J  Yuan H  Lei L  Xiao D 《Talanta》2011,85(5):2344-2351
Gold nanoparticles-poly(luminol) (Plu-AuNPs) hybrid film and multi-walled carbon nanotubes with incorporated β-cyclodextrin modified glassy carbon electrode (β-CD-MWCNTs/Plu-AuNPs/GCE) was successfully prepared for simultaneous determination of dopamine (DA) and uric acid (UA). The surface of the modified electrode has been characterized by X-ray photo-electron spectroscopy (XPS), energy dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscope (SEM) and transmission electron microscope (TEM). Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) have been used to investigate the β-CD-MWCNTs/Plu-AuNPs composite film. Gold nanoparticles anchored into poly(luminol) film exhibited catalytic activity for DA. MWCNTs with incorporated β-CD can greatly promote the direct electron transfer. In 0.10 M phosphate buffer solution (PBS, pH 7.0), the DPV response of the β-CD-MWCNTs/Plu-AuNPs/GCE sensor to DA is about 8-fold as compared with the Plu-AuNPs/GCE sensor, and the detection limit for DA is about one order of magnitude lower than the Plu-AuNPs/GCE sensor. The steady-state current response increases linearly with DA concentration from 1.0 × 10−6 to 5.6 × 10−5 M with a low detection limit (S/N = 3) of 1.9 × 10−7 M. Moreover, the interferences of ascorbic acid (AA) and uric acid (UA) are effectively diminished. The applicability of the prepared electrode has been demonstrated by measuring DA contents in dopamine hydrochloride injection.  相似文献   

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