MOLECULES
·
2014
·Vol. 19
·期 6
·7459-7479
·
IF 2.095
Huawen Hu,John H. Xin,Hong Hu,Xiaowen Wang,Xinkun Lu
In this study, a label-free graphene-based fluorescence probe used for detection of volatile organic liquids was fabricated by a simple, efficient and low-cost method. To fabricate the probe, a bio-based β-cyclodextrin (β-CD) was firstly grafted on reduced graphene surfaces effectively and uniformly, as evidenced by various characterization techniques such as Ultraviolet/Visible spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and transmission electron microscopy. The subsequent inclusion of Rhodamine B (RhB) into the inner cavities of the β-CD grafted on the graphene surfaces was achieved easily by a solution mixing method, which yielded the graphene-based fluorescent switch-on probe. In addition, the gradual and controllable quenching of RhB by Fluorescence Resonance Energy Transfer from RhB to graphene during the process of stepwise accommodation of the RhB molecules into the β-CD-functionalized graphene was investigated in depth. A wide range of organic solvents was examined using the as-fabricated fluorescence probe, which revealed the highest sensitivity to tetrahydrofuran with the detection limit of about 1.7 μg/mL. Some insight into the mechanism of the different responsive behaviors of the fluorescence sensor to the examined targets was also described.Keywords:β-cyclodextrin;graphene oxide;chemical reduction and functionalization;functionalized graphene;Rhodamine B;fluorescence quenching;fluorescence switch-on;fluorescence probe;sensor;sensing platform
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高影响因子
CHEMISTRY OF MATERIALS
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2017
·
IF 9.466
Hao Wu,Zhimin Chen,Jialin Zhang,Feng Wu,Chunying He,Zhiyu Ren,Yiqun Wu
Manipulating the morphology and protonic acid doping of polyaniline (PANI) is significant for optimizing its NH3-sensing. Herein, tetra-β-carboxyphthalocyanine cobalt(II) (TcPcCo) acted as the dopant and structure-directing agent simultaneously to fabricate the uniform fibrous network-like PANI (PANI-TcPcCo hybrids) by a one-step polymerization at low temperature. During the reaction process, the protonic acid groups in TcPcCo not only induced the aniline monomers polymerizing into one-dimensional nanofibers (consist of both solid and hollow cylinders) with abundant tiny protuberances on the surface but also successfully doped into PANI. The resulting PANI-TcPcCo hybrids displayed the enhancement in terms of the good conductivity, the large gas adsorption capacity, and the unobstructed channels for the electron and gas transport. The central metal atoms of TcPcCo present the strong and selective affinity to NH3. Meanwhile, the deep-seated conversion of PANI’s molecular structure after exposure in NH3 could occur due to the presence of TcPcCo. Thus, the PANI-2.5TcPcCo sensor showed the excellent NH3-sensing performance at room temperature, including an ultrahigh and fast response (802.7% and ∼17.0 s for 100 ppm of NH3), a very low detection limit of 10 ppb (about 5000 parts of human olfaction limit of detection, 55 ppm), and superior NH3-sensing stability and selectivity. The strategy developed here provides a reliable and valid way to synthesize functional PANI-based hybrids with unique morphology and appropriate doping, which are able to be extended to other areas.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2017
·
IF 3.154
Liuxi Xia,Yuxiang Bai,Wanmeng Mu,Jinpeng Wang,Xueming Xu,Zhengyu Jin
Instead of β-cyclodextrin (β-CD), branched β-CDs have been increasingly used in many aspects as they possess better solubility and higher bioadaptability. But most commercialized branched β-CDs were chemically synthesized. Thus, the glucosyl-β-cyclodextrin (G1-β-CD) prepared via enzymatic approach could be a nice substitute. However, the yield of G1-β-CD was low. Here, we reported a controlled two-step reaction to efficiently prepare G1-β-CD from maltodextrins by β-cyclodextrin glucosyltransferase (β-CGTase) and amyloglucosidase (AG). Compared to the single β-CGTase reaction, controlled two-step reaction caused a yield increase of G1-β-CD by 130%. Additionally, the percentage of G1-β-CD was enhanced from 2.4% to 24.0% and the side products α-CD and γ-CD were hydrolyzed because of the coupling activity of β-CGTase. Thus, this controlled two-step reaction might be an efficient approach for industrial production of pure G1-β-CD.
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高影响因子
CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY
·
2016
·Vol. 43
·期 5
·562-568
·
IF 2.004
Ailin Xiao,Jing Li,Tianjian Liu,Zhuxi Liu,Chuanfei Wei,Xiaomeng Xu,Qin Li,Jingxin Li
Summary Hydrogen sulphide (H 2 S) is generated endogenously from l -cysteine ( l -Cys) by the enzymes cystathionine- β -synthase (CBS) and cystathionine- γ -lyase (CSE). In addition, l -Cys is commonly used as a precursor in the food and pharmaceutical industries. The aim of the present study is to determine whether l -Cys regulates intestinal nutrient transport. To that end, the presence of CBS and CSE in the jejunum epithelium was assessed by immunohistochemistry, Western blotting and the methylene blue assay. In addition, in vivo l -Cys (100 mg/kg, administered immediately after the glucose load) significantly increased blood glucose levels 30 min after the oral administration of glucose to mice. This effect of l -Cys was completely blocked by amino-oxyacetic acid (AOA; 50 mg/kg; administered at the same time as l -Cys) an inhibitor of CBS. Measurements of the short-circuit current ( I sc ) in the rat jejunum epithelium revealed that l -Cys (1 mmol/L; 6 min before the administration of l -alanine) enhances Na + -coupled l -alanine or glucose transport, and that this effect is inhibited by AOA (1 mmol/L;10 min before the administration of l -Cys), but not d , l -propargylglycine (PAG;1 mmol/L; 10 min before the administration of l -Cys), a CSE inhibitor. Notably, l -Cys-evoked enhancement of nutrient transport was alleviated by glibenclamide (Gli;0.1 mmol/L; 10 min before the administration of l -Cys), a K + channel blocker. Together, the data indicate that l -Cys enhances jejunal nutrient transport, suggesting a new approach to future treatment of nutrition-related maladies, including a range of serious health consequences linked to undernutrition.
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高影响因子
ELECTROANALYSIS
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2016
·Vol. 28
·期 7
·1495-1503
·
IF 2.471
M. Zhang,X. C. Zhai,X. Yang,H. T. Zhao,A. J. Dong,H. Zhang,J. Wang,G. Y. Liu
A rapid method for sensitive voltammetric determination of dinotefuran residue was reported. The proposed method was based on the electrocatalytic reduction of dinotefuran on β-cyclodextrin-graphene composite modified glassy carbon electrode (β-CD-rGO/GCE), giving rise to a higher reduction signal to dinotefuran relative to the bare (GCE) and graphene modified electrode (rGO/GCE). Moreover, a further signal enhancement was observed when the modified electrode incubated in solution at low temperature (0 °C) for a short time. The reduction mechanism and binding affinity were also discussed. The external standard calibration curve was obtained from linear sweep voltammetry in the range of 0.5 to 16.0 μM with a detection limit of 0.10 μM. In addition to optimization of pretreatment, this electrochemical method has been applied to the dinotefuran residue determination in millet samples with the detection limit of 0.01 mg kg −1 and compared with an high performance liquid chromatography method. The proposed electrode and analysis methods were proven to be sensitive, accurate and rapid under the used conditions.
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ACS Applied Materials & Interfaces
·
2017
·
IF 7.504
Qing-Shan Liu,Ran Deng,Qing-Fang Yan,Lin Cheng,Yongming Luo,Keqin Li,Xiaoying Yin,Xiaoyan Qin
In order to efficiently screen and isolate β-tubulin inhibitors, β-tubulin was immobilized on core–shell PMMA/CS (poly(methyl methacrylate)/Chitosan) nanoparticles to produce a new type of immobilized affinity material named β-tubulin-immobilized nanoparticles (β-TIN). The selectivity and adsorption performance of β-TIN were characterized using various control drugs. The β-TIN, the paclitaxel molecularly imprinted ploymers (MIP), and the C18 adsorbing material were compared for selectivity and enrichment ratio. Microtubule-targeting antitumor compounds were screened and isolated from a typical Chinese medicine, Chloranthus multistachys, by β-TIN. Three active compounds (curcolnol, zedoarofuran, and codonolactone) in Chloranthus multistachys extract were captured successfully. Microscale thermophoresis demonstrated that these three compounds strongly bind to β-tubulin, and the dissociation constants (Kd) between the three active compounds and β-tubulin were 1820 ± 0.68 nM, 1640 ± 0.52 nM, and 284 ± 1.00 nM, respectively. Moreover, the binding affinity between codonolactone and β-tubulin was greater than that between paclitaxel and β-tubulin. The antitumor activities of the three compounds were confirmed by the microtubule inhibition model, and the results showed a similar antitumor mechanism as paclitaxel. Molecular dynamics simulations were performed to preliminarily investigate the potential binding sites and the structure–activity relationship between the three active molecules and β-tubulin. Our study is the first to report the use of this novel material which is highly efficient in capturing low-content β-tubulin inhibitors from a complex mixture. The three screened compounds exhibited potential antineoplastic activity, and these lead compounds utilize a new mechanism of action with promising development prospects. Because β-TIN is easily prepared, displays excellent adsorption and selectivity for targets, and can effectively maintain the steric conformation and activities of target proteins, it will be very useful in the screening of lead compounds for different drug target proteins.
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高影响因子
COMPOSITES SCIENCE AND TECHNOLOGY
·
2016
·
IF 3.897
Weichang Li,Junpei Kang,Yulin Yuan,Fengcai Xiao,Hang Yao,Sa Liu,Jianxi Lu,Yingjun Wang,Zhen Wang,Li Ren
The poly(vinyl alcohol) (PVA) hydrogel is regarded as a potential articular cartilage replacement for its good biocompatibility , high permeability to fluid and load-bearing properties. This work investigated a novel Poly(vinyl alcohol)-polyetheretherketone/Poly(vinyl alcohol)-β-tricalcium phosphate (PVA-PEEK/PVA-β-TCP) bilayered hydrogels by freezing-thawing with biomimetic properties for articular cartilage and subchondral bone is developed. The bilayered hydrogels microarchitecture consists of a highly porous and dense structure, and the internal structure were analyzed by micro-CT. The morphology of the resulting hydrogels was analyzed by scanning electron microscopy (SEM), the enhancement of the mechanical properties of the PVA-PEEK/PVA-β-TCP bilayered hydrogels were demonstrated by mechanical testing. The bilayered structure indicate that a good bonding exist between the two layers, which is known to be a requisite necessary to assure a good integrity and functionality of the osteochondral construct. In addition, in vitro cell culture studies revealed that the hydrogels has no negative effect on the cell viability and proliferation and possess good biocompatibility. Then, the bilayered hydrogels were implanted into the knee joint defect of rabbits and hematoxylin and eosin and immunohistochemical staining. The PVA-PEEK/PVA-β-TCP bilayered hydrogels show good potential for use in the field of articular cartilage repair.
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高影响因子
CHINESE JOURNAL OF CHEMISTRY
·
2016
·Vol. 34
·期 6
·599-608
·
IF 1.872
Yehong Zhou,Congli Wang,Fei Wang,Chenzhong Li,Chuan Dong,Shaomin Shuang
β -Cyclodextrin ( β -CD) and its derivatives functionalized magnetic nanoparticles (MNPs) with high saturated magnetism were fabricated successfully by an effective grafting method. The resultant carboxymethyl/hydroxypropyl/sulfobutyl ether- β -CD-MNPs (CM/HP/SBE- β -CD-MNPs) nanocomposites were characterized by the TEM, FTIR, DLS, Zeta potential, XRD and VSM. In addition, the loading and release performance of the as-prepared nanocarriers for the hydrophobic anti-cancer drug curcumin was also investigated. The results revealed that the SBE- β -CD-MNPs possessed the highest loading and release capacity in comparison with other two nanosystems. Cellular uptake and imaging suggested that the SBE- β -CD-MNPs entered into the cell, and curcumin could be successfully delivered into the cell by SBE- β -CD-MNPs nanocarrier. Moreover, cell toxicity experiments demonstrated the SBE- β -CD-MNPs were non-toxic, while curcumin loaded SBE- β -CD-MNPs showed high potential to kill the HepG2 cells. The as-prepared magnetic composites were expected to expand their potential applications in biomedical field.
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高影响因子
Journal of the Taiwan Institute of Chemical Engineers
·
2016
·
IF 2.848
Jia-liang Lv,Shang-ru Zhai,Yuan Fan,Zhi-min Lei,Qing-da An
There is an interesting but challenging task to develop a facile and cost-effective procedure for the making of multifunctional bio-adsorbents for environmental applications. Herein, low-temperature solution-carbonized rice husk (RH-c), β-cyclodextrins (β-CD) and Fe 3 O 4 were synergically combined to prepare a new kind of multifunctional bioadsorbent, i.e . RH-c/Fe 3 O 4 /CD, and applied for the adsorption of methylene blue (MB) from aqueous solution. The structure, morphology and magnetic properties were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FT-IR), 13 C nuclear magnetic resonance spectra (NMR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM) techniques. Initial concentration of MB, contact time, pH effect, adsorption mechanisms and recycling test were also thoroughly investigated. The adsorption equilibrium data was best fitted by Langmuir isotherm model and the adsorption kinetics followed pseudo-second-order models for all samples. The maximum capacity predicted by the Langmuir model is 359.8 and 438.6 mg/g for RH-c/Fe 3 O 4 /CD and RH-c/CD2, respectively. The adsorption test suggested that resulting multifunctional RH-c/Fe 3 O 4 /CD is a promising bioadsorbent for dye molecules removal from aqueous system.
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RSC Advances
·
2016
·Vol. 6
·期 69
·64841-64846
·
IF 3.289
Youzhi Zhou,Jianlin Chu,Jinsong Zhang,Ke Liu,Bingfang He
Efficient synthesis of unitary β-galactosyl nucleoside analogues was successfully achieved in a 10% DMSO solvent system, catalyzed by a newly isolated solvent-stable β-galactosidase from solvent-tolerant Bacillus megaterium YZ08. The most efficient sugar donor for the galactosylation of nucleoside analogues was lactose rather than nitrophenyl glycoside. However, it was accompanied with the formation of complicated digalactosyl nucleoside analogues in the buffer system. The addition of DMSO not only prominently increased the stabilization of β-galactosidase but also regulated the products from complicated products to unitary monogalactosyl nucleoside analogues, which could significantly simplify the process of subsequent separation. Strikingly, the affinity of β-galactosidase to 3′-azido-3′-deoxythymidine in 10% DMSO was significantly enhanced, and the catalytic efficiency (kcat/Km) was doubled as compared to that in buffer solution. These results indicated that solvent-stable glycosidase possesses attractive potency in biosynthesis as well as in regulation of the glycoside prodrugs by adjusting the reaction solvent system.
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高影响因子
JOURNAL OF LUMINESCENCE
·
2016
·
IF 2.693
Hongna Bi,Lin Tang,Xin Gao,Jingjing Jia,Henghui Lv
We investigated the binding interaction between tetracycline hydrochloride (TCH) and bovine proteins β-casein (β-CN), α-lactalbumin (α-LA) in aqueous solution by multi-spectroscopic methods and molecular modeling techniques. Fluorescence and time-resolved fluorescence showed that TCH effectively quenched the intrinsic fluorescence of bovine proteins via static quenching, while there was a single class of binding site on protein. Thermodynamic parameters revealed that electrostatic forces played major roles in the interaction between β-CN and TCH, whereas α-LA-TCH complex were stabilized by hydrogen bonds and van der Waals forces . Moreover, circular dichroism spectra (CD spectra), ultraviolet visible absorption spectra (UV–vis absorption spectra), and fluorescence Excitation-Emission Matrix (EEM) spectra results indicated the secondary structure of bovine proteins was changed in the presence of TCH with the α-helix percentage of protein-TCH complexes decreased. Molecular modeling analysis supported the experimental results well. In addition, the research of surface hydrophobicity further verified tertiary structure of proteins was changed in the presence of TCH and the possible changes of protein function. These results achieved from experiments may be valuable in the milk industry and food safety.
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高影响因子
CARBON
·
2017
·
IF 6.337
Yue Zhang,Zhiyong Guo,Lu Han,Yang Zhang,Xuwei Chen,Jianhua Wang
We report the self-assembly of monolayer polyhedral oligomeric silsesquioxane (POSS) on graphene oxide (GO), where GO acts as a directing template along with the assembly of POSS into a three-dimensional porous framework structure, shortly termed as PPG. The PPG framework contains ultrathin nanopetals with a thickness of ca. 1.95 nm, giving rise to reduced restacking and high surface area. The PPG framework exhibits a high adsorption capacity of up to 1570.3 mg g −1 towards β-lactoglobulin, in addition to a favorable selectivity against other protein species with similar isoelectric points to that of β-lactoglobulin. This might be attributed to the specific hydrogen-bonding donor-acceptor interaction between the calyx structure of β-lactoglobulin and the PPG framework. Satisfactory separation performance of PPG is confirmed by the selective discrimination and isolation of β-lactoglobulin from complex biological sample matrixes, e.g., milk whey. This observation provides a promising approach for the construction of monolayer polymer-modified three-dimensional graphene oxide composites with specific biological application potentials.
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