Nano Research
·
2015
·Vol. 8
·期 12
·3853-3863
·
IF 7.01
Zhang Juan,Lv Jun,Wang Xiaonan,Li Defeng,Wang Zhaoxia,Li Genxi
Here we developed a saccharic colorimetric method based on the combination of chemoselective ligation and enzyme-specific catalysis using aminooxy/hydrazine-functionalized gold nanoparticles (AO/AuNPs or H/AuNPs). In the detection of galactose (Gal), galactohexodialdose (GHDA), the galactose oxidase (GalOx)-catalyzed product, has an aldehyde group, which allows it to chemoselectively react with an aminooxy or hydrazine group at the outer layer of AO/AuNPs or H/AuNPs by oxime/hydrazone click chemistry to form oxime or hydrozone. Consequently, through the specific recognition of 1,4-phenylenediboronic acid (PDBA) on cis-diols, GHDA, which contains two pairs of hydroxyls in the cis form, can bind not only with AO/AuNPs or H/AuNPs, but also with PDBA to form boronate diester, thereby triggering the aggregation of AuNPs and causing the corresponding color change. As GalOx catalyzed specific substrates, the amount of Gal correlated with the production of GHDA and the extent of AuNPs aggregation, thus allowing a simple and easily operatable colorimetric method for Gal detection to be developed. Under the optimized experimental conditions, the ratios of absorbance at a wavelength of 617 nm to that at 536 nm vary linearly with the logarithmic values of Gal concentrations within a wide range of 500 nM to 5 mM. Moreover, this colorimetric method shows anti-interference capability and high sensitivity with a detection limit of 21 nM. Thus, a universal platform for accurate and specific colorimetric analysis can be established through the integration of chemoselective ligation with enzyme specific catalysis.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2015
·Vol. 27
·期 1
·1020-1030
·
IF 1.569
Zhou X. J.,Shi P. H.,Qin Y. F.,Fan J. C.,Min Y. L.,Yao W. F.
Co 3 O 4 /graphene composites were synthesized and their high catalytic activity for the activation of peroxymonosulfate to remove the azo dye (Orange II) in aqueous solutions was found. As for the poor quality of rGO by the chemical process of graphene oxide, here, pristine graphite was exfoliated into graphene flakes through direct sonication with assistance of cetyltrimethyl ammonium bromide, which serves as a dispersant in the solvothermal procedure. The physical and chemical performance of Co 3 O 4 /graphene was characterised by X-ray diffraction, Fourier transform infrared spectroscopy, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy and thermogravimetric analysis. The obtained Co 3 O 4 nanocrystals were 15–25 nm in size and connected with each other to form the shape of sticks dispersing on graphene sheets. The Co 3 O 4 /graphene composites completely degraded Orange II solutions within 10 min, the catalyst can be reutilized, and the catalytic activity of the Co 3 O 4 /graphene dropped slightly after four successive runs. In addition, the mechanism for the formation of Co 3 O 4 /graphene nanostructures is also illustrated.
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BIOMEDICAL MICRODEVICES
·
2015
·Vol. 17
·期 3
·1-8
·
IF 2.877
Song Qi,Gao Yibo,Zhu Qiangyuan,Tian Qingchang,Yu Bingwen,Song Bofan,Xu Yanan,Yuan Maokai,Ma Congcong,Jin Wei,Zhang Tao,Mu Ying,Jin Qinhan
A nanoliter self-priming compartmentalization (SPC) microfluidic chip suited for the digital polymerase chain reaction (dPCR) analysis in point-of-care testing (POCT) has been developed. This dPCR chip is fabricated of polydimethylsiloxane (PDMS). After the dPCR chip is evacuated, there will be a negative pressure environment in the chip because of the gas solubility of PDMS. The negative pressure environment can provide a self-priming power so that the sample solutions can be sucked into each reaction chamber sequentially. The whole sampling process requires no external power and is valve-free. Channels that contain water are designed around each sample panel to prevent the solvent (water) from evaporating during dPCR process. A glass coverslip is also used as a waterproof layer, which is more convenient and more efficient than other waterproof methods seen in literature. This dPCR chip allows three samples to be amplified at the same time. Each sample is distributed into 1040 reaction chambers, and each chamber is only 2.08 nL. Human β-actin DNA solutions of known concentrations are used as the templates for the dPCR analyses to verify the sensitivity and accuracy of the method. Template DNA solutions diluted to concentrations of 300, 100 and 10 copies/μL are tested and shown that this simple, portable and self-priming dPCR chip can be used at any clinic as a real POCT technique.
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PubMed
高影响因子
MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 9
·1791-1796
·
IF 3.741
Li Lu,Lin Zheng-zhong,Chen Xiao-mei,Zhang Hong-yuan,Lin Yi-dong,Lai Zhu-zhi,Huang Zhi-yong
Molecularly imprinted polymer (MIP) particles for malachite green (MG) were prepared by emulsion polymerization using methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, and a combination of Span-80 and Tween-80 as an emulsifier. The MIP particles were characterized by SEM micrographs and FT-IR spectra. Their binding capacity for MG was evaluated based on kinetic and isothermal adsorption experiments and compared to non-imprinted polymer particles. Analytical figures of merit include an adsorption equilibrium time of 15 min, an adsorption capacity of 1.9 mg∙g‾ 1 in acetonitrile-water (20:80), and an imprinting factor of 1.85. The MIP particles were successfully applied to the extraction of MG from fish samples spiked with MG and the other interfering substances prior to its determination of MG by HPLC. Spiked samples gave recoveries of MG that ranged from 86 to 104 %, much higher than that of the other interfering substance.
Molecularly imprinted polymer particles for malachite green (MG) were prepared by emulsion polymerization. They show adsorption capacity of 1.9 mg∙g‾¹ with imprinting factor of 1.85, and were successfully applied to the extraction of MG from spiked fish samples.
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Bioresources and Bioprocessing
·
2014
·Vol. 1
·期 1
·1-8
·
IF 0
Ma Xiaolei,Cao Xuejun
Background Ursodeoxycholic acid is an important clinical drug in the treatment of liver disease. In our previous work, ursodeoxycholic acid was prepared by electroreduction of 7-ketolithocholic acid. The separation of ursodeoxycholic acid from the electroreduction product (47% ( w / w ) ursodeoxycholic acid) by silylation crystallization is described herein. Results N , N -dimethylformamide was used as the solvent, whereas hexamethyldisilazane was the reaction agent. The optimal material ratio of electroreduction product/ N , N -dimethylformamide/hexamethyldisilazane was found to be 1:10:2 ( w / v / v ). The reaction proceeded for 2 h at 60°C, and the corresponding silylation derivative was separated by crystallization and pure ursodeoxycholic acid was recovered by 5% acid hydrolysis at 50°C for 0.5 h. The maximum recovery and purity of ursodeoxycholic acid were 99.8% and 99.5%, respectively. Conclusion Ursodeoxycholic acid with high purity and high recovery can be prepared directly. The developed method offers a potential application for large-scale production of ursodeoxycholic acid.
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
·
2014
·Vol. 31
·期 9
·1608-1615
·
IF 1.241
Liu Qian,Yang Bingchao,Zhang Lujie,Huang Ruihua
A multifunction adsorbent was synthesized by incorporating AC into CTS, and the ratio of AC to CTS was 1/1. The resultant was called activated carbon (AC)/chitosan (CTS) composite. The simultaneous adsorption of phenol and Cu 2+ from aqueous solution onto AC/CTS composite was investigated by a batch procedure. The adsorption processes for both Cu 2+ and phenol obeyed the pseudo second-order kinetic model. Phenol was prone to be adsorbed more quickly as compared with Cu 2+ when they coexisted in solution. The adsorption behavior of both phenol and Cu 2+ followed the Langmuir isotherm. The maximum adsorption capacities of phenol and Cu 2+ were 34.19 mg/g and 74.35 mg/g at 293 K, respectively. No obvious competitive adsorption existed between phenol and Cu 2+ .
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Food and Bioprocess Technology
·
2014
·Vol. 7
·期 11
·3121-3135
·
IF 3.126
Tian Ye,Fu Nan,Wu Winston Duo,Zhu Danhua,Huang Jinjian,Yun Shuo,Chen Xiao Dong
Dairy industries often spray lecithin, a food-grade surfactant, to spray-dried whole milk powders while fluidisation to produce instant powders. Though adding surfactant to milk feed was often reported to improve the wettability of dried powders, this approach was not favourably used. The present study investigated the effects of surfactant addition into high solids milk feed before drying on the wettability of whole milk particles. Adding either 0.1 wt.% Tween 80 or 0.1 wt.% lecithin to un-concentrated whole milk led to a significant wettability improvement of spray-dried powders. At higher feed solids levels of 23 and 33 wt.%, the wetting process of pure milk powders was comparatively rapid, but the surfactant-added powders showed similar wettability to the pure milk powders. The development of powder wettability as drying progressed was investigated using single droplet-drying technique for 32 and 43 wt.% whole milk in the presence and absence with surfactants. The technique captured an advanced shell formation during drying of higher solids milk. The wettability of surface shells formed by surfactant-added milk was similar to those formed by pure milk throughout drying, from initial shell formation to final drying stage. By contrast, coating surfactants on the outer layer of particles being dried could substantially improve wettability. The rapid shell formation and the slow material diffusion owing to the high medium viscosity were considered the main factors limiting the migration of surfactant molecules towards droplet surface during drying.
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CELLULOSE
·
2014
·Vol. 21
·期 4
·2469-2478
·
IF 3.033
Sun Peipei,Kuga Shigenori,Wu Min,Huang Yong
Dry ball milling of graphite with cellulose and related polysaccharides was found effective for exfoliation-dispersion of graphene-like carbon. The exfoliation behavior was found to depend strongly on the polymer species; namely, polysaccharides are much more effective than thermoplastic polymers. The compression-molded slabs from co-milled powder with cellulose and carboxymethylcellulose showed an electrical percolation threshold of 1.0 % (w/w) or lower. The carbon fraction isolated from milling with carboxymethylcellulose was water-dispersible, containing single- to few-layer graphenes. This method can provide facile and solventless graphene exfoliation and mechanical alloying with polymers.
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Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-5
·
IF 2.481
Wang Yanming,Wang Yajing,Wang Fei
Well-crystallized Li 2 NiTiO 4 nanoparticles are rapidly synthesized by a molten salt method using a mixture of NaCl and KCl salts. X-ray diffraction pattern and scanning electron microscopic image show that Li 2 NiTiO 4 has a cubic rock salt structure with an average particle size of ca. 50 nm. Conductive carbon-coated Li 2 NiTiO 4 is obtained by a facile ball milling method. As a novel 4 V positive cathode material for Li-ion batteries, the Li 2 NiTiO 4 /C delivers high discharge capacities of 115 mAh g -1 at room temperature and 138 mAh g -1 and 50°C, along with a superior cyclability.
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高影响因子
CELLULOSE
·
2014
·Vol. 21
·期 4
·2369-2378
·
IF 3.033
Xiao Peng,Zhang Jinming,Feng Ye,Wu Jin,He Jiasong,Zhang Jun
Using ionic liquid 1-allyl-3-methylimidazolium chloride as reaction medium, a series of novel cellulose esters containing phosphorus including cellulose diphenyl phosphate (C-Dp) and cellulose acetate (CA)–diphenyl phosphate mixed esters was synthesized homogeneously. The degree of substitution was well controlled by altering reaction conditions, such as the molar ratio of the acylating reagents/anhydroglucose unit and reaction time. The structure and thermal properties of cellulose esters were characterized by FTIR, NMR, wide-angle X-ray powder diffraction and differential scanning calorimetry. All the products possessed excellent solubility in some common organic solvents, and transparent films of cellulose esters were obtained by solution casting. In contrast to C-Dp, CA–diphenyl phosphate mixed esters showed clear glass transitions. More interestingly, these cellulose mixed esters exhibited thermoplastic behavior and could be processed by traditional melt processing methods.
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POLYMER BULLETIN
·
2014
·Vol. 71
·期 7
·1797-1811
·
IF 1.491
Chen Haochuan,Jiao Jiao,Zhao Changwen,Ma Yuhong,Ma Wenchao,Yang Wantai
Organotellurium compounds-mediated living radical polymerization (TERP) is one of the most robust tools of living free radical polymerizations (LRP). However, synthesis and purification of organotellurium compounds are time-consuming and to be operated in an inert atmosphere due to their extreme sensitivity to trace oxygen. In this article, a simple process of TERP, operating in open air, has been reported. It has demonstrated that the crude organotellurium compound, ethyl 2-phenyltellanyl-2-methylpropionate, could mediate 2,2′-azobis (isobutyronitrile) initiated styrene (St) and butyl acrylate (BA) polymerization as an LRP system. For the bulk and solution polymerization of St and the solution polymerization of BA, the molecular weights of produced polymers increased linearly with the monomer conversions. During the same time, the molecular weight distributions kept under 1.3. The UV–vis spectrum showed that the PS polymer chain bearing C-TePh end group. With the sequential monomer addition technique, a clean diblock polymer of PS- b -PBA was also obtained.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2014
·Vol. 32
·期 5
·577-586
·
IF 1.42
Chen Shu-fan,Sun Lian-lai,Luo Xuan,Jiang Xiao-dong,Wu Wei-dong,Fang Yu,Huang Chuan-qun,Yang Rui-zhuang,Zhang Qing-jun
Carbazole-based bi-functional photorefractive polyacrylates were prepared via free radical polymerization and post-azo-coupling reaction. The structure of polymers was characterized by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H-NMR) spectroscopy. The differential scanning calorimetry (DSC) and the thermal gravimetric analysis (TGA) were used to characterize the thermal property of polymers. The results indicate that though the glass transition temperature ( T
g ) of polymers increases with increasing the ratio of NLO groups, the polymers with different ratios of NLO groups still all show low glass transition temperatures around 60 °C, and good thermal stability, which are favorable to the practical application of these polymers. The gel permeation chromatographic (GPC) result indicates that these polymers all have high-molecular-weight which is favorable to the long term stability of the material. Further, these polymers have good solubility in chloroform solvent, and the solutions can easily be fabricated into optically transparent films. Gain coefficients of 75 cm −1 , 185 cm −1 and 66 cm −1 can be observed at zero external electric field without any addition agent or pre-poling for polymers P-2, P-3 and P-4 respectively. The different contents of NLO groups result in the different properties of polymers P-2, P-3 and P-4.
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