SURFACE AND INTERFACE ANALYSIS
·
2014
·Vol. 47
·期 2
·270-277
·
IF 1.393
Yongli Shi,Suying Ma,Ruiqiong Tian,Yingge Zhao,Qian Jiao,Xu Ma,Qing Shang
A novel amphiphilic copolymer was synthesized from poly (ethylene glycol) methyl ether methacrylate (PEGMA950), methyl methacrylate (MMA) and acryloyl- β -cyclodextrin (acryloyl- β -CD) using the composites of (NH 4 ) 2 S 2 O 8 /NaHSO 3 as the oxidation–reduction initiators. The successful fabrication of poly(PEGMA-co-MMA-co-acryloyl- β -CD) copolymers was confirmed by Fourier transform infrared spectrometer (FTIR), 1 H-nuclear magnetic resonance ( 1 H NMR) spectra. The amphiphilic copolymer could self-assemble into nanoparticles (NPs), and their morphology and particle size distribution were characterized with transmission electron microscopy (TEM), atomic force microscope (AFM) and dynamic light scattering (DLS) methods. Ibuprofen (IBU) was encapsulated in the novel NPs, and the release profiles of IBU were investigated. FTIR and 1 H NMR spectra illustrated that the poly(PEGMA-co-MMA-co-acryloyl- β -CD) copolymers were synthesized without any residual monomers and initiators. TEM and AFM photographs suggested that the obtained NPs were spherical, and the DLS results indicated that the diameter of blank NPs was 157.3 ± 32.7 nm. The IBU release profile showed that the IBU-loaded NPs had certain pH responsibility. Copyright © 2014 John Wiley & Sons, Ltd.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2013
·Vol. 4
·期 2
·554-562
·
IF 2.562
Tianzhi Yu,Yan Cao,Wenming Su,Chengcheng Zhang,Yuling Zhao,Duowang Fan,Mingjun Huang,Kan Yue,Stephen Z. D. Cheng
A new iridium complex containing coumarin derivative as a cyclometalated ligand (1L) and a carbazole-functionalized β-diketonate (2L) as the ancillary ligand, namely, Ir(III)bis(3-(pyridin-2-yl)coumarinato-N,C4)(1-(9-butyl-9H-carbazol-3-yl)-4,4,4-trifluoro-butane-1,3-dionato-O,O) (Ir(1L)2(2L)), was synthesized. The crystal structure of Ir(1L)2(2L) was determined via combined wide angle X-ray diffraction (WAXD) and transmission electron microscopy (TEM), which showed π–π the interactions of Ir(1L)2(2L) molecules stacking along the crystal axes. The doped light-emitting diodes using this novel Ir(1L)2(2L) complex as the phosphorescent dopant were fabricated. At a Ir(1L)2(2L) concentration of 6.0 wt%, a green-yellow emitting OLED was achieved with a maximum external quantum efficiency (EQE) of 6.11% and a maximum luminous efficiency of 22.55 cd A−1 at the current density of 6.06 mA cm−2, and a maximum luminance of 6653 cd m−2 at 10.7 V. Furthermore, two reference complexes Ir(1L)2(acac) and Ir(1L)2(TTA) were also used as emitters to fabricate OLED devices with the same device configuration. The maximum luminous efficiency of Ir(1L)2(acac) doped device was measured to be 20.04 cd A−1 at 2.15 mA cm−2 (10.0 wt%), while the doped device of Ir(1L)2(TTA) had a maximum luminous efficiency of 16.59 cd A−1 at 1.36 mA cm−2. The better performances of Ir(1L)2(2L) doped devices could be largely attributed to an improved hole-transporting property due to the introduction of the carbazole moiety.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2014
·Vol. 16
·期 9
·1-9
·
IF 2.278
Cui Hongtao,Xue Junying,Ren Wanzhong,Wang Minmin
In this work, β-Ni(OH) 2 monolayer nanosheets were prepared in benzyl alcohol by a facile exfoliation-free sol–gel route. The hydrolysis reaction of metal ions was started with the ring-opening reaction of epoxide. The in situ modification of benzyl alcohol molecules on the surface of secondary growth unit of hydroxide allowed the formation of β-Ni(OH) 2 monolayer nanosheets and 100 % monolayer state of β-Ni(OH) 2 in the resultant suspension. As proven in the electrochemical measurement, the maximum specific capacitance of 1735 F g −1 was obtained at scan rate of 5 mV s −1 within potential window of 0.6 V in 6 mol l −1 KOH aqueous solution, which is equal to the theoretical value of β-Ni(OH) 2 . This high electrochemical performance is attributed to the complete exposure of every structure unit of β-Ni(OH) 2 to electrolyte. This work demonstrates that monolayer nanosheets can generate from the brucite-type nickel hydroxide through this bottom-up strategy although it had been theoretically considered to be impossible.
✓ 已验证
产品关联
DOI
高影响因子
BIOSENSORS & BIOELECTRONICS
·
2015
·
IF 6.409
Yizhen Yang,Feng Gao,Xili Cai,Xiaoning Yuan,Suyu He,Fei Gao,Hongxu Guo,Qingxiang Wang
A versatile nanocomposite containing β-cyclodextrin and graphene (CD–GR) was prepared through a simple chemical reduction method. The characterization experiments show that the nanocomposite remains the flake-like morphology of GR, but its solubility and stability in aqueous solution are greatly improved. Then the nanocomposite was modified at glassy carbon electrode (GCE) surface, and was used as a functional matrix for the covalent immobilization of probe DNA using 2,4,6-trichloro-1,3,5-triazine (TCT) as the crosslinker . Due to the synergetic effect of large surface area of GR and rich hydroxyl of CD, the probe density for the developed biosensor was determined to as high as 3.82×10 13 molecules cm − 2 . Meanwhile, the biosensor shows high hybridization efficiency and hybridization kinetic. When the biosensor was applied for the impedance-based hybridization test, a wide linear range from 1.0×10 −16 to 1.0×10 −12 M and an ultralow detection limit of 3.4×10 −17 M were achieved. The biosensor also displays excellent stability, selectivity , and reproducibility.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Yu Zhang,Gang Hu,Lin Hu,Jimei Song
This paper reports a novel method for identification of two aliphatic position isomers between α-ketoglutaric acid (α-KA) and β-ketoglutaric acid (β-KA) by their different perturbation effects on a Briggs–Rauscher oscillating system, in which tetraaza-macrocyclic complex [NiL](ClO4)2 is used as the catalyst. The ligand L in the complex is 5,7,7,12,14,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-4,11-diene. The experimental results have shown that addition of α-KA into the system does not affect the oscillating patterns, while the presence of β-KA in a dynamic system influences the oscillatory amplitude. A more interesting feature is that, in the presence of a higher concentration of β-KA, there are damped oscillations after the initial spike, followed by quenching (more exactly: very small oscillations) of the oscillations before the subsequent regeneration of oscillations. A qualitative approach was thus established by employing a Briggs–Rauscher system for identification of these two isomers. The concentrations of these two isomers that can be distinguished lie over the range between 5.0 × 10–6 and 2.5 × 10–3 mol/L. A reaction mechanism based on the FCA model has been proposed. An explanation is that β-KA reacts with HOO• radicals to form acetone, whereas the α-KA does not.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 84
·68397-68403
·
IF 3.84
Huimin Duan,Leilei Li,Xiaojiao Wang,Yanhui Wang,Jianbo Li,Chuannan Luo
In this report, a sensitive and selective chemiluminescence (CL) biosensor for bovine serum albumin (BSA) coupled with a surface molecularly imprinted polymer nanocomplex using β-cyclodextrin/chitosan–magnetic graphene oxide as backbone material (β-CD/Cs–MGO–SMIP) was investigated. The material β-CD/Cs–MGO combined with β-cyclodextrin, chitosan and graphene oxide was used to provide multiple imprinting sites and a large surface area was characterized by SEM, XRD and FTIR. It was found that β-CD/Cs–MGO–SMIP followed the Langmuir isotherm equation and pseudo-second order sorption kinetics when binding the template. This material demonstrated fast mass transfer, a promoted rate of removal of the biomacromolecule and excellent recognition and adsorption ability for the imprinting cavities situated at the surface of β-CD/Cs–MGO, which enabled easy access to BSA. Subsequently, a highly sensitive CL biosensor for BSA was proposed based on the strong recognition effect between β-CD/Cs–MGO–SMIP and BSA which led to a high selectivity of the sensor, and the proposed biosensor could assay in the range 5.0 × 10−7 to 1.0 × 10−4 mg mL−1 with a detection limit of 1.1 × 10−7 mg mL−1. The obtained recoveries were between 94% and 106% when determining samples.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 75
·60775-60785
·
IF 3.84
Xin Ran,Long Yang,Genfu Zhao,Hanzhang Ye,Yanqiong Zhang,Shuangmei Fan,Xiaoguang Xie,Hui Zhao,Can-Peng Li
In the present work, ultrafine Pd clusters with a uniform size of ∼2.0 nm were monodispersed on the surface of reduced graphene oxide (RGO) using a clean and green approach in the absence of additional reductants and surfactants. Disulfide linked β-cyclodextrin dimer (SS-β-CD) was non-covalently bonded to the surface of Pd@RGO. By combining the merits of Pd@RGO and the SS-β-CD, a highly sensitive electrochemical sensing platform was developed based on the SS-β-CD–Pd@RGO nanohybrids. Simultaneous electrochemical detection of baicalin and luteolin using a SS-β-CD–Pd@RGO nanohybrid-modified electrode is described for the first time. The SS-β-CD showed a higher supramolecular recognition capability than the native β-CD, which may be caused by the cooperative binding abilities of two adjacent CD units. Due to the synergistic effects from the Pd@RGO (e.g. good electrochemical properties and large surface area) and SS-β-CD (e.g. hydrophilic external surface, high supramolecular recognition, and good enrichment capability), the SS-β-CD–Pd@RGO modified electrode was found to have linear response ranges of 0.02–20.00 μM for baicalin and 0.01–10.00 μM for luteolin with relatively low detection limits of 0.0052 μM for baicalin and 0.0070 μM for luteolin. The results indicated that SS-β-CD–Pd@RGO nanohybrids are excellent sensing materials for the electrochemical determination of flavonoids. The proposed method could be successfully utilized to detect baicalin and luteolin in serum samples, and has a promising application in practice.
✓ 已验证
产品关联
DOI
高影响因子
Journal of Physical Chemistry C
·
2015
·
IF 4.772
Yongxin Tao,Xiaogang Gu,Linhong Deng,Yong Qin,Huaiguo Xue,Yong Kong
We report a Cu2+-modified β-cyclodextrin, Cu2-β-CD, that was self-assembled on poly(l-glutamic acid) (P-l-Glu) for chiral recognition of d-tryptophan (d-Trp). Cu2+ formed binuclear hydroxy-bridge (Cu(OH)2Cu) at the wider opening of the cavity of β-CD and acted as a cap to prevent high-energy water molecules from being released while forcing Trp isomers to enter through its narrower opening. Because H-bonds were favored to form between the high-energy water molecules and the amino groups of d-Trp inside the cavity of β-CD, d-Trp was thus recognized. The recognition capability of the Cu2-β-CD appeared to depend on the way the Cu2-β-CD self-assembled onto P-l-Glu, preferring via H-bonds rather than via electrostatic interactions, because electrostatic interactions between P-l-Glu and Cu(OH)2Cu could alter the configuration of the Cu2-β-CD cavity, resulting in weakened H-bonds between high-energy water molecules and d-Trp.
✓ 已验证
产品关联
DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2015
·Vol. 99
·期 9
·4019-4029
·
IF 3.337
Wan Nan-Wei,Liu Zhi-Qiang,Xue Feng,Huang Kai,Tang Ling-Jiao,Zheng Yu-Guo
Halohydrin dehalogenases (HHDHs) are an important class of enzymes for preparing optically active haloalcohols, epoxides, and β-substituted alcohols. However, natural HHDHs rarely meet the requirements of industrial applications. Here, a novel high-throughput screening (HTS) methodology for directed evolution of HHDH was developed based on the colorimetric determination of azide. In this method, azide was involved in the HHDH-catalyzed ring-opening process and the decrease of azide was used to quantitatively evaluate HHDH activity. The HTS methodology was simple and sensitive (ε 460 = 1.2173 × 10 4 L mol −1 cm −1 ) and could be performed in a microplate format using whole cells. To verify the efficiency of the HTS methodology, it was adopted to engineer a HHDH (HHDH-PL) from Parvibaculum lavamentivorans DS-1, which was applied in the process for ethyl ( R )-4-cyano-3-hydroxybutanoate (HN) by the conversion of ethyl ( S )-4-chloro-3-hydroxybutanoate (( S )-CHBE)). A random mutant library containing 2500 colonies was screened using the HTS methodology, and three beneficial mutants F176M, A187R, and A187S were obtained. By combining the beneficial mutated residues, the variant F176M/A187R was identified with 2.8-fold higher catalytic efficiency for preparation of HN. The high-throughput colorimetric assay would be very useful for directed evolution of HHDH for preparing β-substituted alcohols.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ANNALS OF BIOMEDICAL ENGINEERING
·
2016
·Vol. 44
·期 11
·3372-3383
·
IF 2.887
Xie Bei,Peng Jian,Wang Shuo,Zhang Xing,Nie Hemin
The combination of gene therapy and chemotherapy has showed increased therapeutic efficacy in the treatment of cancers, but it is not well investigated about the actual coordination pattern between therapeutic gene and chemical drug. In this work, p53/BPEI-β-CD/AD-dox complex was fabricated and employed to investigate the interaction manner between p53 and doxorubicin (Dox). Briefly, branched polyethylenimine (BPEI) was conjugated with β-cyclodextrin hydrate (β-CD) to form BPEI-β-CD backbone, and p53 plasmid was condensed by positively charged BPEI via electrostatic interaction, while Dox was first conjugated with adamantine (AD) and then assembled with BPEI-β-CD backbone via the host–guest interaction. It was found that the BPEI-β-CD backbone possessed high endocytosis efficiency but low cytotoxicity. Moreover, p53/BPEI-β-CD/AD-dox complex released Dox and enabled the expression of p53 gene in a sequential manner, and the released Dox and expressed p53 gene showed successive inhibition of the growth of HeLa cells in vitro . With the ability to co-deliver chemical drug and therapeutic gene and exert their inhibitory actions on tumor cell growth in a sequential manner, this DNA/BPEI-β-CD/AD-drug complex via electrostatic interaction and host–guest assembly not only achieved long-term efficacy in inhibiting tumor cell growth but also can be employed as a platform to investigate the coordination pattern between chemical drugs and therapeutic genes for other purposes.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 46
·29025-29034
·
IF 3.108
Pengfei Chen,Hang Song,Shun Yao,Xianyu Tu,Miao Su,Lu Zhou
Magnetic targeted nanoparticles double coated with β-cyclodextrin (β-CD) and chitosan (CS) were formed using a layer-by-layer model and their potential for hydrophobic drug delivery was evaluated in the study reported here. The resulting nanoparticles (NPs) had an average size of 102 nm and were spherical in shape. The double polymer layers ensured the colloidal stability and biocompatibility of the nanocarriers. Ibuprofen was chosen as the model drug. The nanocarriers possessed good magnetic properties and exhibited a high loading capacity that depended on the hybrid effects of electrostatic interaction and inclusion provided by the CS layer and the β-CD layer, respectively, which was confirmed using zeta potential analysis and a molecular modeling study. The in vitro release results revealed that the two-step release process consisted of an initial fast release and then a slower sustained release. Based on the Korsmeyer–Peppas model, the release mechanism was attributed to a mixed effect of swelling and a diffusion controlled release, which could be affected by pH, temperature and magnetic field. It is anticipated that the CS–CD–silica coated magnetic nanoparticles (SMNPs) will be a promising candidate as a nanocarrier for hydrophobic drugs.
✓ 已验证
产品关联
DOI
高影响因子
DYES AND PIGMENTS
·
2017
·
IF 3.473
Lanxiang Liu,Juan Xu,Hua Zheng,Kun Li,Wenwen Zhang,Kai Li,Hong Zhang
This study aimed to investigate the formation of three inclusion complexes of laccaic acid A (the main component of the lac dye, named as LA) with β -cyclodextrin ( β -CD), methyl- β -cyclodextrin (M- β -CD), or (2-hydroxyethyl)- β -cyclodextrin (HP- β -CD), exploring particularly the effects of CDs on the solubility of LA and the binding ability of the final inclusion complexes. Lac dye, a natural colorant , had been widely used in food and textile industry. Because of its low water solubility, the application of this nontoxic dye was restricted. This study employed β -cyclodextrin and its derivatives to encapsulate the hydrophobic part of LA and resolve the aforementioned limitation. The binding constants ( K c ) and solubility of LA were determined with the three β -CDs using the phase-solubility method, which followed the rank order of HP- β -CD > M- β -CD > β -CD. The inclusion interactions between LA and β -CDs were detected using the Fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance. Moreover, the scanning electron microscope and transmission electron microscope were applied to characterize the appearance of the inclusion complexes. This study would provide a useful approach for obtaining novel LA-based products with high water solubility and low toxicity.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）