Frontiers of Environmental Science & Engineering
·
2019
·Vol. 13
·期 6
·1-10
·
IF 3.883
Liang Bin,Kong Deyong,Qi Mengyuan,Yun Hui,Li Zhiling,Shi Ke,Chen E.,Vangnai Alisa S.,Wang Aijie
Trimethoprim (TMP) is an antibiotic frequently detected in various environments. Microorganisms are the main drivers of emerging antibiotic contaminant degradation in the environment. However, the feasibility and stability of the anaerobic biodegradation of TMP with sulfate as an electron acceptor remain poorly understood. Here, TMP-degrading microbial consortia were successfully enriched from municipal activated sludge (AS) and river sediment (RS) as the initial inoculums. The acclimated consortia were capable of transforming TMP through demethylation, and the hydroxyl-substituted demethylated product (4-desmethyl-TMP) was further degraded. The biodegradation of TMP followed a 3-parameter sigmoid kinetic model. The potential degraders ( Acetobacterium, Desulfovibrio, Desulfobulbus , and unidentified Peptococcaceae) and fermenters ( Lentimicrobium and Petrimonas ) were significantly enriched in the acclimated consortia. The AS- and RS-acclimated TMP-degrading consortia had similar core microbiomes. The anaerobic biodegradation of TMP could be coupled with sulfate respiration, which gives new insights into the antibiotic fate in real environments and provides a new route for the bioremediation of antibiotic-contaminated environments.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 2
·1-9
·
IF 5.479
Zhang Kai,Cao Jinxuan,Wu Yongxiang,Hu Futao,Li Tianhua,Wang Ying,Gan Ning
A simple and highly sensitive fluorometric method is described for the determination of the antibiotic kanamycin (Kana) in food. Dual signal amplification is accomplished by making use of double Y-shaped aptamer DNA probes acting as a capture probes and signal amplification probes. The DNA probes were immobilized on a gold bar and on a magnetic bar, respectively. On addition of Kana, the Y-shaped aptamer probe captures Kana and then is disassembled to release two single-stranded DNAs. These trigger target recycling and HCR between the two bars simultaneously. As a result, many long duplex DNA chains are formed in the supernatant. After pulling out the bars and adding the fluorescent intercalating probe SYBR Green I, strong fluorescence (with excitation/emission peaks at 497/525 nm) is induced. The use of such double Y-shaped DNA probes obviously overcomes the unspecific signal amplification by HCR which increases selectivity and sensitivity. This is due to the fact that the hairpin of HCR is separated in being present in different arms of the Y-shaped probe. Under the optimal conditions, the assay has a limit of 0.45 pg·mL −1 for Kana. It was applied to analyze spiked milk, fish and pork samples.
The scheme represents a sensitive fluorometric aptamer-based method to detect kanamycin (Kana). It is making use of a double stirring bar-assisted dual amplification strategy with zero background. Abbreviations: apt: aptamer, AuNPs: gold nanoparticles, HCR: hybridization chain reaction.
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CELLULOSE
·
2019
·Vol. 26
·期 4
·2861-2872
·
IF 3.917
Cheng Quan-Yong,Guan Cheng-Shu,Li Yi-Dong,Zhu Jiang,Zeng Jian-Bing
Traditional superhydrophobic cotton fabrics (CF) demonstrate various advantages such as self-cleaning, water repelling and efficient oil/water separation capacity but limited practical applications due to their poor mechanical robustness and environmental durability. In this work, robust and durable superhydrophobic polydivinylbenzene (PDVB) coated CF (PDVB@CF) are fabricated via a simple one-step, fluorine-free, and inorganic nanoparticle-free solvothermal method. The PDVB@CF displays excellent chemical resistance without losing superhydrophobicity after immersing in various organic solvents, strong acid and alkali solutions for a long time. The PDVB@CF shows excellent mechanical robustness to resist sandpaper abrasion and ultrasonication treatment. Furthermore, the PDVB@CF exhibits outstanding high and low temperature resistances since the contact angle of either acidic or alkali droplets is greater than 150° after isothermal treatment at 200 °C or immersion in liquid nitrogen for 3 h. The PDVB@CF is very efficient in separating water mixtures with various oily compounds with separation efficiency of higher than 98% and flux up to 56 k L m −2 h −1 depending on characteristics of the oils. In addition, the PDVB@CF shows excellent recyclability with superhydrophobicity and separation efficiency that remained after 10 separation cycles. The PDVB@CF with excellent robustness and durability exhibits potential utility in oil/water separation even under some harsh conditions.
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JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
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2019
·Vol. 89
·期 3
·641-650
·
IF 1.986
Wang Pengpeng,Li Jie,Chen Lianxi,Fang Jinjin
Abstract In this study, a new-style “ex-situ charge interaction” strategy has been developed to prepare graphene oxide/organic functionalized silica nanoparticles (GO/OSNs) composites. The crucial point of the strategy is that the OSNs have positive charge by adding Hydrochloric acid (HCl). Four types of OSNs were prepared via one-pot sol–gel reaction of four different kinds of organosilane. Then the positively charge OSNs and negatively charge GO could effectively composite via charge interaction. The GO/OSNs were characterized by Scanning electron microscope (SEM), Transmission electronic microscope (TEM), Fourier transform infrared (FT-IR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The results showed that “ex-situ charge interaction” strategy might be a general method for the fabrication of GO/OSNs. This research provides a new approach for the fabrication of GO/OSNs composites with other OSNs structures. In addition, the application of GO/OSNs in the adsorption of Cd(II) has also been investigated, which included adsorption properties of four GO/OSNs, parameters of adsorption isotherm and adsorption kinetics.
GO/OSNs composites were fabricated based on a new-style “ex-situ charge interaction” strategy. OSNs were first prepared via one-pot sol–gel reaction. Furthermore, they were given positive charge by adding HCl. Finally, GO/OSNs were fabricated by charge interaction of between GO and OSNs.
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JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2019
·Vol. 34
·期 1
·216-222
·
IF 0.605
Chen Shaoyun,Liu Ben,Wang Yuan,Cheng Huan,Zhang Xingying,Xu Shaoqin,Liu Hui,Liu Wenfeng,Hu Chenglong
A simple route to synthesize the polyaniline (PANI) nanofibers with diameter about 150 nm was reported. In this strategy, the PANI nanofibers were fabricated by electrochemical deposition by using two-electrode configuration in 0.01 M aniline and 0.01 M H 2 SO 4 electrolytes. The as-prepared materials were characterized by scanning electron microscopy (SEM), infrared spectroscopy (FTIR), Raman spectroscopy and thermogravimetric analysis (TGA). The electrochemical properties of the PANI nanofibers electrode as supercapacitor materials were investigated. The PANI nanofibers electrode showed high capacitance of 485 F·g -1 at 0.1 A·g -1 , and the decrease in the specific capacitance is about 3.5% in 1 000 cycles. The results indicate that the PANI nanofibers electrode shows high stability and retains its electrochemical capacitance property over 1 000 cycles, suggesting PANI nanofibers have promising applications in high-performance supercapacitors.
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Biotechnology for Biofuels
·
2019
·Vol. 12
·期 1
·1-15
·
IF 5.452
Zhang Yanjuan,Huang Min,Su Jianmei,Hu Huayu,Yang Mei,Huang Zuqiang,Chen Dong,Wu Juan,Feng Zhenfei
Background Due to biomass recalcitrance, including complexity of lignocellulosic matrix, crystallinity of cellulose, and inhibition of lignin, the bioconversion of lignocellulosic biomass is difficult and inefficient. The aim of this study is to investigate an effective and green pretreatment method for overcoming biomass recalcitrance of lignocellulose.Results An effective mechanical activation (MA) + metal salt (MAMS) technology was applied to pretreat sugarcane bagasse (SCB), a typical kind of lignocellulosic biomass, in a stirring ball mill. Chlorides and nitrates of Al and Fe showed better synergistic effect with MA, especially AlCl3, ascribing to the interaction between metal salt and oxygen-containing groups induced by MA. Comparative studies showed that MAMS pretreatment effectively changed the recalcitrant structural characteristics of lignocellulosic matrix and reduced the inhibitory action of lignin on enzymatic conversion of SCB. The increase in hydroxyl and carboxyl groups of lignin induced by MAMS pretreatment led to the increase of its hydrophilicity, which could weaken the binding force between cellulase and lignin and reduce the nonproductive binding of cellulase enzymes to lignin.Conclusion sMAMS pretreatment significantly enhanced the enzymatic digestibility of polysaccharides substrate by overcoming biomass recalcitrance without the removal of lignin from enzymatic hydrolysis system.
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JOURNAL OF MATERIALS SCIENCE
·
2019
·Vol. 54
·期 8
·6027-6037
·
IF 3.442
Yang Dexin,Yang Tao,Chen Yulong,Liang Yu,Liu Yan’gai
Double perovskite La 2 CoMnO 6 is an attractive spintronics with magnetoelectric, magnetodielectric, and magnetoresistive effects, which are related, at least in part, to combined structural and magnetic instabilities. To explore its magnetoelastic coupling behaviour, a conventional analysis of lattice parameter data in terms of spontaneous strain shows that the ferromagnetic ordering process is accompanied by significant volume ( e aM ) and shear ( e tM ) strains. The DC and AC magnetic data reveal the antisite defects with antiphase regions, and the ferromagnetic transition is at ~ 230 K with a small antiferromagnetic ordering at about 170 K. In addition, the Rietveld refinement of the in situ variation X-ray diffraction from 120 to 1400 K, scanning electron microscopy, and differential scanning calorimetry were used to confirm the crystal structure, microstructure, magnetic, and structural anomalies of the sample synthesised in pure oxygen atmosphere. This study, and in particular the strain analysis, of La 2 CoMnO 6 will facilitate its potential application in the field of spin electronics and thin-film engineering.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 2
·1-10
·
IF 5.479
Yang Jinlan,Song Naizhong,Jia Qiong
An electrostatically controlled fluorometric assay is described that is based on the use of silver/copper bimetallic nanoclusters. The nanoclusters were coated with polyethyleneimine (PEI-Ag/CuNCs). At pH 7.4, these particles are positively charged. Their blue fluorescence (with excitation/emission peaks at 341/464 nm) depends on local pH values and temperature. If graphene oxide (which is negatively charged at pH 7.4) is introduced, the fluorescence of the PEI-Ag/CuNCs is quenched. Based on various electrostatic interactions, three kinds of biomacromolecules were detected by fluorometry. These include (negatively charged) heparin, (positively charged) protamine, and (virtually uncharged) trypsin. Heparin is detected by using GO/PEI-Ag/CuNCs, protamine by using GO/heparin/PEI-Ag/CuNCs, and trypsin by using GO/protamine/heparin/PEI-Ag/CuNC. The detection limits and linear ranges are 4.8 nM and 10–450 nM for heparin, 0.09 μg·mL −1 and 0.25–5 μg·mL −1 for protamine, and 0.03 μg·mL −1 and 0.05–1 μg·mL −1 for trypsin. Zeta potentials of the various substances in the system were determined to elucidate the detection mechanism. Comceivably, the method provides a widely applicable approach for electrostatically controlled biomolecular assays.
Schematic presentation of electrostatically controlled fluorometric assay for the detection of heparin, protamine, and trypsin based on the silver/copper bimetallic nanoclusters modified with polyethyleneimine and graphene oxide.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 3
·504-508
·
IF 1.071
Cao Jing,Wang Miao,Chen Weihua,She Yongxin,Wang Jing,Wang Fengzhong,Lao Shuibing
A novel artificial esterase based on chitosan and amino acids was synthesized in the present study. The Fmoc-His and Glu were linked to chitosan by active ester method(AEM). The hydroxide radical in chitosan, imidazole group of Fmoc-His and carboxyl from Glu formed a catalytic center of natural esterase. Gel microspheres were coated with a protective layer and a supporting layer by self-assembly construction function in carboxymethylcellulose sodium(CMCS) solution. As for catalytic activity, chitosan-His-Glu was found to be more efficient than chitosan- His and chitosan-Glu in mimicking the core catalytic sites of natural esterase, and the best ratio(mass ratio) of chitosan-His-Glu:CMCS was 1:3. Furthermore, metal ions, such as Ca 2+ , Mg 2+ , Fe 2+ , etc., were able to improve the catalytic efficiency of artificial esterase. And the Lineweaver-Burk plot indicated that the catalytic kinetics of artificial esterase conformed to Michaelis-Menten equation.
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Journal of Inorganic and Organometallic Polymers and Materials
·
2019
·Vol. 29
·期 6
·1874-1885
·
IF 1.637
Wang Hongpeng,Lin Yuecheng,Li Yin,Dolgormaa Anudari,Fang Hui,Guo Lin,Huang Jun,Yang Junxing
To improve the adsorption capacity of Cd(II) ions, Cd(II) ions were imprinted on the surface of aminoethyl chitosan (AECS), which was coated on Fe 3 O 4 @SiO 2 nanoparticles. A novel magnetic Cd(II) ion-imprinted polymer (Cd(II)-IIP) was synthesized, characterized, and applied to the selective separation of Cd(II) ions from aqueous solution. The adsorption–desorption properties and selectivity of Cd(II)-IIP and a non-imprinted polymer (Cd(II)-NIP) were investigated. The optimum pH and equilibrium binding time were established at pH 6.0 and 60 min, respectively. Kinetics studies demonstrated that the adsorption process proceeded according to a pseudo-first or second order model, while the adsorption isotherms agreed with the Langmuir model. The maximum adsorption capacities of Cd(II)-IIP and Cd(II)-NIP toward Cd(II) ions, as calculated by the Langmuir equation, at pH 6.0 and 25 °C were 26.1 and 6.7 mg/g, respectively. The imprinted polymer showed higher selectivity toward Cd(II) ions compared to the non-imprinted polymer. The relative selectivity factor ( β r ) values of Cd(II)/Cu(II), Cd(II)/Cr(II), and Cd(II)/Pb(II) were 3.315, 3.875, and 2.061, respectively. In addition, Cd(II) ions adsorbed on the Cd(II)-IIP adsorbent could be easily released using 0.1 M HNO 3 , thus showing good material stability and reusability. The adsorption capacity of Cd(II)-IIP was retained at 74% after undergoing six adsorption–desorption cycles.
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IONICS
·
2019
·Vol. 25
·期 9
·4351-4360
·
IF 2.289
Yu Zhongliang,Zhang Jiahe,Xing Chunxian,Hu Lei,Wang Lili,Ding Ming,Zhang Haitao
Boron-nitrogen co-doped graphene nanoarchitectures were synthesized by annealing a freeze-dried precursor containing exfoliated graphene oxide (GO) nanosheets, ammonium borate, and polyvinyl alcohol (PVA). The microstructures and composition of nanocomposites were optimized and characterized systemically. Effects of a doping element on the electrochemical performances and interface compatibility were evaluated. The restacking of exfoliated graphene nanosheets was hindered effectively by the ultra-fine carbon clusters formed via the thermal decomposition of PVA. Such a three-dimensional structure favors the fast mobility of electrolyte ions. In addition, the co-doping of N and B elements not only increases interface compatibility between ionic liquid electrolyte and graphene but also supplies extra pseudocapacitance. Benefiting from the integrated merits, the optimized nanocomposites could deliver a specific capacitance of 35.4 F g −1 at 1 A g −1 and present a maximum energy density of 78.7 Wh kg −1 with a power density of 2043 W kg −1 . Due to the formation of more decoupled ions in ionic liquid electrolyte at elevated temperature, the symmetric supercapacitors based on the as-formed nanocomposite exhibit a maximum energy density of 134.6 Wh kg −1 at 60 °C.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 5
·1-7
·
IF 5.479
Ran Peiyao,Song Jinyi,Mo Fangjing,Wu Jingling,Liu Pingkun,Fu Yingzi
Nitrogen-doped graphene quantum dots (N-GQDs) were prepared from dicyandiamide and then used as both an electrochemiluminescence (ECL) emitter and a reductant to produce gold nanoparticles (Au-N-GQDs) on their surface without using any reagent. In order to avoid resonance energy transfer, the Au-N-GQDs were stabilized with chitosan. Transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDX), UV-vis spectroscopy (UV-vis) and ECL methods were used to characterize the nanocomposite. The materials was placed on a glassy carbon electrode (GCE), and the ECL signals are found to be strongly quenched by hydrogen peroxide that is enzymatically produced by oxidation of glucose. With the applied typical potential of −1.7 V, the ECL of the Au-N-GQDs modified GCE decreases linearly in the 10 nM to 5.0 μM glucose concentration range, and the lower detection limit is 3.3 nM. The influence of H 2 O 2 to the signal has been discussed and a possible mechanism has been presented.
Schematic presentation of the reduction of gold nanoparticles with nitrogen-droped graphene quantum dots (N-GQDs) to form Au-N-GQDs. They were used to detect glucose by electrochemiluminescence through a signal off strategy.
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