MICROCHIMICA ACTA
·
2014
·Vol. 181
·期 9
·1069-1075
·
IF 3.719
Ling Yu,Li Jia Xing,Qu Fei,Li Nian Bing,Luo Hong Qun
We report that the intensity of the blue fluorescence of copper nanoclusters coated with polyethyleneimine (PEI) is strongly reduced in the presence of the food dyestuffs Sudan I-IV. This finding was exploited in a label-free fluorescence assay for these Sudan dyes both in ethanol and aqueous solutions. The PEI-capped nanoclusters have an average diameter of 1.8 nm and are displaying, under 355 nm excitation, a blue emission at 480 nm that matches the absorption bands of the Sudan dyes. The clusters are stable in solution for at least 1 month. Under optimum conditions, this assay can be applied to the quantification of the dyes Sudan I, II, III, and IV, respectively, in the 0.1−30, 0.1–30, 0.1–25, and 0.1–25 μM concentration ranges, and the detection limits (3σ/slope) are 65, 70, 45, and 50 nM, respectively. The capability of reducing the fluorescence of the PEI-capped copper nanoclusters is directly related to the number of the functional groups in that Sudan III and IV give lower detection limits. This analytical scheme exhibits a remarkably high selectivity for the Sudan dyes over potentially interfering substances. The method was successfully applied to determine Sudan I, II, III, and IV in hot chilli powder.
The blue fluorescence emission of copper nanoclusters coated with polyethyleneimine (PEI) is strongly reduced in the presence of Sudan I-IV. This finding was exploited in a label-free fluorescence assay for these Sudan dyes both in ethanol and aqueous solutions.
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Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-8
·
IF 2.481
Abdiryim Tursun,Ali Ahmat,Jamal Ruxangul,Osman Yakupjan,Zhang Yu
Poly(3,4-ethylenedioxythiophene)/zinc oxide (PEDOT/ZnO) nanocomposites were prepared by a simple solid-state heating method, in which the content of ZnO was varied from 10 to 20 wt%. The structure and morphology of the composites were characterized by Fourier transform infrared (FTIR) spectroscopy, ultraviolet-visible (UV-vis) absorption spectroscopy, X-ray diffraction (XRD), and transmission electron microscopy (TEM). The photocatalytic activities of the composites were investigated by the degradation of methylene blue (MB) dye in aqueous medium under UV light and natural sunlight irradiation. The FTIR, UV-vis, and XRD results showed that the composites were successfully synthesized, and there was a strong interaction between PEDOT and nano-ZnO. The TEM results suggested that the composites were a mixture of shale-like PEDOT and less aggregated nano-ZnO. The photocatalytic activity results indicated that the incorporation of ZnO nanoparticles in composites can enhance the photocatalytic efficiency of the composites under both UV light and natural sunlight irradiation, and the highest photocatalytic efficiency under UV light (98.7%) and natural sunlight (96.6%) after 5 h occurred in the PEDOT/15wt%ZnO nanocomposite.
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Nanoscale Research Letters
·
2015
·Vol. 10
·期 1
·1-10
·
IF 2.779
Xu Jing,Xing Wei,Zhao Lianming,Guo Feifei,Wu Xiaozhong,Xu Wenbin,Yan Zifeng
To study the effect of interlayer spacing of pillared graphene oxides (GOs) on CO 2 uptake, we have obtained CO 2 isotherms with respect to the interlayer distance of pillared graphene oxide by both experimental and simulation methods. Interlayer distances of GO were modulated by intercalation of three kinds of diaminoalkanes with a different number of carbon atoms (NH 2 (CH 2 )
n
NH 2 , n = 4, 8, and 12) as pillars. The intercalated GOs (IGOs) and their reduced products (RIGOs) are characterized using a variety of approaches such as X-ray powder diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), and N 2 adsorption. Gas adsorption performance shows that the CO 2 uptake of IGOs and RIGOs decrease with the increase of the interlayer distance at low pressure, while at high pressure, the adsorption capacity of IGO-12 has a larger growth than those of both IGO-4 and IGO-8 and surpasses them at 30 bar. The contribution of the electrostatics to CO 2 adsorption is larger than that of van der Waals force at low pressures, whereas for the high pressures, the adsorption is dominated by van der Waals force.
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CATALYSIS LETTERS
·
2015
·Vol. 145
·期 10
·1830-1836
·
IF 2.307
Zhou Yan,Huang Wei,Chen Xiang-Shu,Song Zhi-Bin,Tao Duan-Jian
Abstract Several tetramethylguanidinum-based ionic liquids (TMGILs) were prepared, characterized and used as catalysts in one-pot synthesis of flavanones. The results indicated that TMGILs composed of phenolate anion was beneficial for one-pot synthesis of flavanones, and [TMG][4-MeO–PhO] induced the good yields of flavanones owing to the electron-donating effect of methoxy substituent on phenolate anion. Furthermore, [TMG][4-MeO–PhO] was found to be used repetitively at least five times without obvious decrease in activity and quantity. Graphical Abstract
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MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 13
·2353-2359
·
IF 3.741
Zhang Xi,Zang Xiao Huan,Wang Jun Tao,Wang Chun,Wu Qiu Hua,Wang Zhi
A nanoporous carbon derived from an aluminum-based metal-organic framework was deposited on stainless steel wires in a sol–gel matrix. The resulting fibers were applied to the solid-phase microextraction of the polycyclic aromatic hydrocarbons (PAHs) naphthalene, acenaphthene, fluorene, phenanthrene and anthracene from water and soil samples. The fiber was then directly inserted into the GC injector and the PAHs were quantified by GC-MS. The effects of salt addition, extraction temperature, extraction time, sample volume and desorption conditions on the extraction efficiency were optimized. A linear response to the analytes was observed in the 0.1 to 12 μg∙L −1 range for water samples, and in the 0.6 to 30 μg∙kg −1 for soil samples, with the correlation coefficients ranging from 0.9934 to 0.9985. The limits of detection ranged from 5.0 to 20 ng∙L −1 for water samples, and from 30 to 90 ng∙kg −1 for soil samples. The recoveries of spiked samples were between 72.4 and 108.0 %, and the precision, expressed as the relative standard deviations, is <12.8 %.
A MOF derived nanoporous carbon coated fiber for use in solid-phase microextraction was prepared via sol–gel technology. The coated fiber has a porous, rough and wrinkled structure, and shows a high thermal stability, good extraction repeatability and long lifetime. The established HS-SPME-GC-MS method is suitable for the determination of the PAHs from water and soil samples.
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International Journal of Environmental Science and Technology
·
2015
·Vol. 13
·期 1
·113-124
·
IF 2.19
Wang Z.,Ye C.,Wang H.
Amino group exhibits alkaline properties. Amino functionalized imidazole-modified silicas would benefit the adsorption of phenolic compounds. Coupling agent between the silica and the imidazolium ring has an effect on adsorption performance. In this paper, two adsorbents were synthesized for the surface bonding of N -(3-aminopropyl)-imidazole onto silicas modified by 3-chloropropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane, respectively. Infrared spectra, elemental analysis, thermogravimetric analysis and N 2 adsorption–desorption isotherms were used to characterize the two adsorbents, and their adsorption capacities of 2,4-dinitrophenol from aqueous solutions were investigated in detail. The experimental results indicated that amino group plays an important role in the enhancement of adsorption capacities of 2,4-dinitrophenol. The adsorbent with 3-mercaptopropyltrimethoxysilane as coupling agent exhibited lower adsorption capacity due to a weak electron–electron repulsion between the non-bonding electrons of sulfur atom and π electrons of benzene ring of 2,4-dinitrophenol. The adsorption kinetics fitted well with pseudo-second-order model. The two adsorbents could be regenerated and reused eight times at least by washing with HCl. The adsorption mechanism was also discussed.
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JOURNAL OF SOILS AND SEDIMENTS
·
2015
·Vol. 15
·期 5
·1139-1149
·
IF 2.139
Wang Chen,Zhu Lizhong,Zhang Chunlong
Purpose The speciation of soil organic pollutants is of great importance for risk assessment and contaminant remediation, however, only few studies have attempted to develop a speciation scheme for a facilitated risk assessment. This paper postulates a pragmatic speciation scheme for the fractionation of soil polycyclic aromatic hydrocarbons (PAHs) that could correlate with their bioavailabilities, and the aim was to develop a reliable sequential ultrasonic extraction scheme that could differentiate PAHs into four fractions with different environmental relevance. We also investigated the key factors to the fraction distribution of PAHs, as well as the relationship between bioavailability of PAHs and their fractions. Materials and methods Four representative PAHs were spiked into two soils and the distribution of PAH fractions was measured over a period of 90 to 210 days. The reliability of the sequential ultrasonic extraction method was cross-examined by an isotope experiment. The key factors to the fraction distribution, including aging time and properties of soil and PAH, were tested using ultrasonic extraction. The correlation between four fractionated PAHs and their bioavailabilities was assessed with a semipermeable membrane device (SPMD)-assisted desorption assay that mimics the bioconcentration of PAHs. Results and discussion Soil PAHs were speciated into water-soluble-, organic acid-soluble-, organically bound-, and residual fractions via sequential ultrasonic extraction. The water-soluble- and organic acid-soluble fractions, which approximated the total PAHs estimated by SPMD, corresponded to the most bioavailable portions. The latter ones decreased significantly during aging. In contrast, the residual fraction, which limits the effectiveness of remediation, increased during aging following methanolic saponification. The concentrations of water-soluble-, organic acid-soluble-, and organically bound fractions are negatively correlated with the soil organic matter content and the partition coefficient between octanol and water ( K
ow ) of pollutants Conclusions The bioavailability of soil PAHs can be mimicked by a sequential chemical extraction protocol developed in this study. This speciation scheme can be readily used for studying the environmental fate and risk of PAHs, providing us with better rationales in selecting remediation strategies of soil contaminated with PAHs based bioavailability.
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FOOD SCIENCE AND BIOTECHNOLOGY
·
2015
·Vol. 24
·期 3
·843-850
·
IF 0.653
Zhu Chang-Yue,Wang Xiao-Peng,Zhao Xin-Huai
Transglutaminase at a concentration of 10 kU/kg of protein and degraded chitosan were used for glycosylation and crosslinking of caseinate at a fixed molar ratio of the acyl acceptor to the acyl donor of 3:1, a protein concentration of 50 g/L, a pH 7.5 at 37°C, and a reaction time of 4 h. Electrophoretic and chemical analyses showed glycosylation and crosslinking of caseinate. Glycosylated and crosslinked caseinate (GC-caseinate) contained glucosamine at 12.77 g/kg of protein, and the protein fraction had fewer reactable amino groups than original caseinate (0.58 vs. 0.64 mol/kg of protein). GC-caseinate exhibited an enhanced surface hydrophobicity, in vitro digestibility, water-binding capacity, and rheological properties, with poor protein dispensability and emulsification activity, but a similar oilbinding capacity and emulsion stability, compared with original caseinate. GC-caseinate also exhibited better properties than transglutaminase-crosslinked caseinate. Glycosylation and crosslinking was effective for better water-binding and rheological properties of caseinate.
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EUROPEAN JOURNAL OF PLANT PATHOLOGY
·
2015
·Vol. 142
·期 3
·547-556
·
IF 1.49
Luo Zaiqi,Guo Huili,Yang Yadong,Yang Mingfen,Ma Lanqin,Wang Younian
Huping jujube is widely cultivated in northern China. PcPKS5, a resveratrol synthase (STS) gene, contains all functionally divergent plant specific type III PKSs and is involved in resveratrol synthesis. This study aimed to assess the effects of heterologous overexpression of the resveratrol synthase (PcPKS5) gene on Huping jujube (Ziziphus jujuba Mill.) plant resistance and nutritional quality. Stems with leaves and shoot tips of Huping jujube (Ziziphus jujuba Mill) were infected with agrobacterium expressing PcPKS5 and GUS, and three positive plants were identified. Resveratrol (0.45 μg/g fresh weight) was detected by HPLC in line 2 transgenic plants. Interestingly, 100 μl extract of 1 g/ml transgenic plant crude extract showed an inhibitory effect equivalent to 1.0 μg of pure resveratrol. In addition, transgenic plants displayed increased anti-mite resistance compared with the wild-type counterparts. Importantly, higher PcPKS5 expression levels were found in young tissues compared with the stem and mature leaves. This study also provides a stable genetic transformation mechanism for developing new plant germplasms in Huping jujube.
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JOURNAL OF POLYMER RESEARCH
·
2015
·Vol. 22
·期 4
·1-8
·
IF 1.92
Cheng Chuanjie,Bai Xiongxiong,Zhang Xu,Li Hongxia,Huang Qinghua,Tu Yuanming
A symmetric photo-active trithiocarbonate was designed and synthesized, which can act not only as a functional reversible addition-fragmentation chain transfer (RAFT) agent, but also as a crosslinker in crosslinking poly(methyl methacrylate- co -hydroxy ethyl acrylate) (poly(MMA- co -HEA)) due to interactions of benzophenone moieties of trithiocarbonate and hydroxyl groups of poly(MMA- co -HEA) under UV irradiation. In addition, the crosslinked poly(MMA- co -HEA) demonstrates photo-promoted self-healing properties by reshuffling C-S bonds of trithiocarbonate.
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Nanoscale Research Letters
·
2014
·Vol. 9
·期 1
·1-9
·
IF 2.481
Zhao Qin,Jamal Ruxangul,Zhang Li,Wang Minchao,Abdiryim Tursun
In this study, a simple one-step template-free solution method was developed for the preparation of poly(3,4-ethylenedioxythiophene) (PEDOTs) with different morphologies by adjusting various ratios of oxidant (FeCl 3 ·6H 2 O) to monomer (3,4-ethylenedioxythiophene (EDOT)). The results from structural analysis showed that the structure of PEDOT was strongly affected by the oxidant/monomer ratio, and the polymerization degree, conjugation length, doping level, and crystallinity of PEDOT decreased with increasing of the oxidant/monomer ratio. The morphological analysis showed that PEDOT prepared from an oxidant/monomer ratio of 3:1 displayed a special coral-like morphology, and the branches of ‘coral’ would adjoin or grow together with increasing content of oxidant in the reaction medium; consequently, the morphology of PEDOT changed from coral to sheets (at an oxidant/monomer ratio of 9:1). The electrochemical analysis proved that the PEDOT prepared from an oxidant/monomer ratio of 3:1 had the lowest resistance and the highest specific capacitances (174 F/g) at a current density of 1 A/g with a capacity retention rate of 74% over 1,500 cycles, which indicated that the PEDOT with a coral-like morphology could be applied as a promising electrode material for supercapacitors.
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JOURNAL OF NANOPARTICLE RESEARCH
·
2015
·Vol. 17
·期 10
·1-10
·
IF 2.184
Chen Daquan,Wang Guohua,Song Weiguo,Zhang Qiang
Most anticancer drugs cannot kill cancer stem cells (CSCs) effectively, which lead to the failure of anticancer chemotherapy, such as relapse and metastasis. In this study, we prepared a multifunctional oligosaccharides of hyaluronan (oHA) conjugates, oHA-histidine-menthone 1,2-glycerol ketal (oHM). The oHM conjugates possess pH-sensitive menthone 1,2-glycerol ketal (MGK) as hydrophobic moieties and oHA as the target of CD44 receptor. Anticancer drugs, curcumin(Cur) and paclitaxel(PTX), were loaded into oHM micelles via self-assembly. Then, oHM micelles were mineralized through controlled deposition of inorganic calcium and phosphate ions on the nanoparticular shell via a sequential addition method to fabricate the “nano-eggs.” The formed nano-eggs had a smaller size (120.6 ± 4.5 nm) than oHM micelles (158.6 ± 6.4 nm), indicating that mineralization made the appearance of compact nanoparticles. Interestingly, when the nano-eggs were put into the acidic conditions (pH 6.5), their outer shell(inorganic minerals) will be destroyed with the larger size, while the “nano-eggs” were stable under pH 7.4. For both nano-eggs and oHM micelles, the Cur and PTX were released in a sustained manner depending on the pH of the solution. However, the nano-eggs showed much lower released than the oHM micelles due to the dissolution of the inorganic minerals and pH-sensitive ketal at mildly acidic environments (pH 6.5). In vivo study, the nano-eggs could get to the tumor site more effectively than oHM micelles. CSCs were sorted by a side population assay from MDA-MB-231 breast cancer cell lines over-expressing CD44 receptors. Antitumor activity was also evaluated on MDA-MB-231 xenografts in nude mice. The antitumor efficacy indicated that nano-eggs with co-delivery of Cur and PTX produced the strongest antitumor efficacy, and nano-eggs showed strong activity against cancer stem cells. These double pH-sensitive nano-eggs may provide a promising strategy for drug delivery to both cancer cells and cancer stem cells.
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