APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2016
·Vol. 182
·期 1
·261-275
·
IF 1.606
Jiang Cheng,Song Jinzhu,Cong Hua,Zhang Junzheng,Yang Qian
A novel β-1,3-glucanase gene, designated Ccglu17A , was cloned from the biological control fungus Chaetomium cupreum Ame. Its 1626-bp open reading frame encoded 541 amino acids. The corresponding amino acid sequence showed highest identity (67 %) with a glycoside hydrolase family 17 β-1,3-glucanase from Chaetomium globosum . The recombinant protein Ccglu17A was successfully expressed in Pichia pastoris , and the enzyme was purified to homogeneity with 10.1-fold purification and 47.8 % recovery yield. The protein’s molecular mass was approximately 65 kDa, and its maximum activity appeared at pH 5.0 and temperature 45 °C. Heavy metal ions Fe 2+ , Mn 2+ , Cu 2+ , Co 2+ , Ag + , and Hg 2+ had inhibitory effects on Ccglu17A, but Ba 2+ promoted the enzyme’s activity. Ccglu17A exhibited high substrate specificity, almost exclusively catalyzing β-1,3-glycosidic bond cleavage in various polysaccharoses to liberate glucose. The enzyme had a Km of 2.84 mg/mL and Vmax of 10.7 μmol glucose/min/mg protein for laminarin degradation under optimal conditions. Ccglu17A was an exoglucanase with transglycosylation activity based on its hydrolytic properties. It showed potential antifungal activity with a degradative effect on cell walls and inhibitory action against the germination of pathogenic fungus. In conclusion, Ccglu17A is the first functional exo-1,3-β-glucanase to be identified from C. cupreum and has potential applicability in industry and agriculture.
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高影响因子
CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2016
·Vol. 32
·期 6
·924-928
·
IF 1.086
Qi Pengjia,Wang Ziying,Wang Rui,Xu Yinan,Zhang Tong
Synthetic graphene composite was modified on a transducer of quartz crystal microbalance(QCM) to fabricate a gas sensor for low concentration nitrogen dioxide(NO 2 ) detection. The gas sensing properties of the QCM coated with SnO 2 -rGO and AgNPs-SnO 2 -rGO composites were investigated when exposing QCM to low NO 2 con-centration(2.05—20.5 mg/m 3 ) atmosphere at room temperature. The sensing performances of the QCM with AgNPs-SnO 2 -rGO composites were enhanced by the introduction of Ag nanoparticles, and the QCM modified with AgNPs-SnO 2 -rGO composites could detect NO 2 at room temperature.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 9
·2401-2410
·
IF 3.431
Zhang Haijuan,Qiao Xin,Cai Tianpei,Chen Jia,Li Zhan,Qiu Hongdeng
In this paper, N-doped carbon dots (NCDs) were successfully decorated on the spherical porous silica surface in deep eutectic solvents (DESs) as a novel class of green solvents. The appropriate density and hydrophility of DESs guaranteed the fine dispersibility of silica particles and NCDs, resulting in a homogeneous and thin layer of NCDs immobilization. As compared with traditional organic solvents (DMF and THF), higher surface coverage was obtained in the medium of DES, proving its feasibility as a new kind of alternative solvent for hydrophilic nanomaterial-based surface modification of silica spheres. The resulting NCDs-decorated silica particles (Sil-NCDs) were characterized in detail and packed into chromatographic columns to study their initial feasibility as adsorbent material for liquid chromatography. The resultant packing materials demonstrate a selective behavior for polar compounds in hydrophilic interaction liquid chromatography (HILIC) mode. This work gives a typical example of using carbon dots as stationary phase component, and such material is hopeful to be used in other research fields such as solid absorbents, recycling catalysts, and solid-state electrochemistry etc.
N-doped carbon dots (NCDs) were successfully coupled on the surface of porous silica spheres in a green strategy using deep eutectic solvents (DES) as media for HILIC.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
·
2017
·Vol. 409
·期 8
·2179-2187
·
IF 3.431
Wang Heping,Jiao Fenglong,Gao Fangyuan,Zhao Xinyuan,Zhao Yan,Shen Yehua,Zhang Yangjun,Qian Xiaohong
Deep and efficient proteolysis is the critical premise in mass spectrometry-based bottom-up proteomics. It is difficult for traditional in-solution digestion to meet the requirement unless prolonged digestion time and enhanced enzyme dosage are employed, which makes the whole workflow time-consuming and costly. The abovementioned problems could be effectively ameliorated by anchoring many proteases on solid supports. In this work, covalent organic framework-coated magnetic graphene (MG@TpPa-1) was designed and prepared as a novel enzyme carrier for the covalent immobilization of trypsin with a high degree of loading (up to 268 μg mg −1 ). Profiting from the advantages of magnetic graphene and covalent organic frameworks, the novel trypsin bioreactor was successfully applied for the enzymatic digestion of a model protein with dramatically improved digestion efficiency, stability, and reusability. Complete digestion could be achieved in a time period as short as 2 min. For the digestion of proteins extracted from Amygdalus pedunculata , a total of 2833 protein groups were identified, which was slightly more than those obtained by 12 h of in-solution digestion (2739 protein groups). All of the results demonstrate that MG@TpPa-1-trypsin is an excellent candidate for sample preparation in a high-throughput proteomics analysis.
Covalent organic frameworks-coated magnetic graphene was prepared as novel carrier for highly efficient tryptic immobilization
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JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 8
·4460-4471
·
IF 2.599
Chen Zhou,Dong Yunyun,Jiang Shaoyang,Song Wenjing,Lai Weikun,Yi Xiaodong,Fang Weiping
Hierarchical SAPO-11 was successfully synthesized without a secondary template by changing the hydrothermal crystallization temperature. SAPO-11 with a larger external surface area, more acidity, and a large number of external active sites was constructed through a novel two-step crystallization strategy. Both precrystallization step and the low-temperature crystallization step were confirmed to be indispensable conditions for constructing hierarchical SAPO-11. After loading Pt nanoparticles by incipient wetness impregnation, the heptane hydroisomerizations based on 0.5 wt% Pt/C-SAPO-11-200 and 0.5 wt% Pt/T-SAPO-11-120 catalysts were carried out in a fixed-bed at a total pressure of 1.5 MPa with a H 2 /n-heptane volumetric of 400 and WHSV = 10 h −1 . A conversion level of 75.7% of 0.5 wt% Pt/T-SAPO-11-120 catalyst was reached, which was higher than that of 0.5 wt% Pt/C-SAPO-11-200 catalyst (64.3%) at 300 °C. The enhanced performance achieved was attributed to the improved effect of the support, in terms of not only better mass transport and higher number of exposure active sites but also improved dispersity and decrease in the size of Pt particles.
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MICROCHIMICA ACTA
·
2017
·Vol. 184
·期 3
·855-861
·
IF 4.58
Huang Yaxun,Tang Chen,Liu Jin,Cheng Jun,Si Zhongzhou,Li Ting,Yang Minghui
The authors describe a strategy for improving the sensitivity of electrochemical immunoassays that is based on the use of hydroxyapatite nanoparticles (HAP-NPs). Signal generation is based on the reaction of phosphate groups present in HAP-NPs with molybdate to form a redox-active molybdophosphate precipitate on the surface of the electrode that facilitates the generation of an electrochemical current. The cancer biomarker α-fetoprotein (AFP) was chosen as a model antigen (analyte). Antibodies against AFP (Ab 2 ) were immobilized on the HAP-NPs to obtain the signal probe. The reaction of HAP-NPs with molybdate and the performance of the immunoelectrode were characterized in detail. Based on this signal amplification approach, an immunoassay was worked out that has a linear range that extends from 0.1 pg·mL −1 to 1 ng·mL −1 and a detection limit as low as 50 fg·mL −1 . The assay was successfully applied to the determination of AFP in serum samples. In our perception, this new signal amplification scheme can be adapted to numerous other immunoassays.
Schematic of the electrochemical assay for the cancer biomarker α-fetoprotein based on hydroxyapatite (HAP) nanoparticles as signal probe. The reaction of HAP nanoparticles with molybdate leads to the formation of a redox-active molybdophosphate precipitate on the electrode surface and generates an electrochemical current.
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CHINESE JOURNAL OF POLYMER SCIENCE
·
2017
·Vol. 35
·期 3
·446-454
·
IF 1.692
Chen Bin,Chen Jia,Li Jing-yu,Tong Xin,Zhao Hai-chao,Wang Li-ping
A critical challenge for initiating many applications of the carbon nanotubes (CNTs) is their dispersion in organic solvent or in polymer melt. In the present study, we described a novel strategy for fabricating carbon nanotubes (CNTs)-reinforced epoxy nanocomposite by utilizing aniline trimer (AT) as the noncovalent dispersant. Tensile testing showed that the tensile modulus of the CNTs-reinforced epoxy composites was considerably improved by adding a small amount of AT functionalized CNTs. Additionally, the as-prepared CNTs-epoxy nanocomposites exhibited superior tribological properties with much lower frictional coefficients and wear rates compared to those of neat epoxy resin. The well dispersed AT-functionalized CNTs in epoxy matrix played an important role in enhancing the mechanical properties, as well as acting as a solid lubricant for improving the tribological performance of epoxy/CNTs nanocomposite.
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JOURNAL OF MATERIALS SCIENCE
·
2017
·Vol. 52
·期 9
·5155-5164
·
IF 2.599
Wang Mingjie,Shen Shuling,Li Long,Tang Zhihong,Yang Junhe
The effect of sacrificial reagents (SRs) on photocatalytic H 2 evolution rate over different photocatalysts was systematically studied. Zn 0.5 Cd 0.5 S, graphitic carbon nitride (g-C 3 N 4 ), and TiO 2 were chosen as typical photocatalysts, while alcohols, amines, carboxylic acids, and inorganic Na 2 S/Na 2 SO 3 were chosen as SRs. The results indicate that Na 2 S/Na 2 SO 3 , methanol, and triethanolamine are the most suitable SRs for Zn 0.5 Cd 0.5 S, TiO 2 , and g-C 3 N 4 , respectively. It was found that in selecting organic SRs, both the permittivity and oxidation potential have profound effects on the H 2 production efficiency, which will provide basis for choosing appropriate SRs for different photocatalysts.
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JOURNAL OF POROUS MATERIALS
·
2016
·Vol. 24
·期 1
·257-265
·
IF 1.385
Jiang Wei,Wu Juan,Tian Renbing,Jiang Wei
Magnetic mesoporous nanocomposites are emerging as a significant new material to improve the effectiveness of cancer treatment and enhance the availability of drug therapy. Thus, the core–shell structure magnetic mesoporous nanocomposites (Fe 3 O 4 @SiO 2 @LDH) were synthesized with an average diameter of about 100 nm and used as methotrexate (MTX) carriers for cancer therapy. As an important biological material, Fe 3 O 4 @SiO 2 @LDH exhibited higher superparamagnetic behavior and biocompatibility, and the drugs can be loaded in the channels of the mesoporous silica and the interlayer of layered double hydroxides (LDH). The embedding rate of magnetic mesoporous silica (Fe 3 O 4 @SiO 2 ) and LDH were 60.32 % and 0.67 %, respectively, and the release rate of the drug delivery systems (Fe 3 O 4 @SiO 2 @LDH-MTX) was 66.81 %. In addition, LDH as a kind of pH-sensitive material was adopted for controlled drug release and WST-1 assays in cancer cells (Hela) demonstrated that Fe 3 O 4 @SiO 2 @LDH-MTX presented high anti-tumor activity, while the carriers were nearly non-toxic. Therefore, all the results suggested that the magnetic nanocomposites can be employed to deliver MTX, and would be applied in the field of cancer therapy in the future.
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ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2016
·Vol. 23
·期 20
·20672-20679
·
IF 2.76
Chen Xiao,Li Hongbing,Liu Xiaoyan,Zhang Xinying,Liang Xia,He Chiquan,Cao Liya
The in situ chemical oxidation technology (ISCO) and phytoremediation for PAHs have been studied respectively, but few focus on the feasibility of combining persulfate with ryegrass. This literature revealed the effect of persulfate oxidation on the growth of ryegrass and the removal ratios of pyrene in the couple system of persulfate oxidation and phytoremediation. The results demonstrated that half of pyrene in test soil was oxidized by persulfate in 7 days and then the residual pyrene concentration was decreased to a lower level by ryegrass in the following 2 months in oxidation treatment and drip washing and plants (OWP) and oxidation treatment and drip washing and plants and fertilization (OWFP) treatment. Ryegrass could grow well after persulfate oxidation with the oxidized soil washed by water. Ryegrass in OWP and OWFP treatments had higher ratios of overground and underground biomass. However, the seeds of ryegrass cannot germinate when drip washing was omitted. Pyrene together with residual persulfate changed soil enzyme activities. Drip washing and the growth of ryegrass made soil enzyme activities tend to returned to normal levels. Persulfate oxidation and phytoremediation were compatible to make contributions to the dissipation of pyrene. Persulfate oxidation activated by heat had higher removal efficiency of PAHs and phytoremediation could further decrease the pyrene concentration in spiked soil.
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高影响因子
Nano Research
·
2016
·Vol. 9
·期 10
·2960-2971
·
IF 8.893
Peng Haitao,Sun Weihai,Li Yunlong,Ye Senyun,Rao Haixia,Yan Weibo,Zhou Huanping,Bian Zuqiang,Huang Chunhui
An inverted planar heterojunction perovskite solar cell (PSC) is one of the most competitive photovoltaic devices exhibiting a high power conversion efficiency (PCE) and nearly free hysteresis in the voltage–current output. However, the band alignment between the transport materials and the perovskite absorber has not been optimized, resulting in a lower open-circuit voltage ( V
oc ) than that of regular PSCs. To address this issue, we tune the band alignment in perovskite photovoltaic architecture by introducing bilayer structured transport materials, e.g., the hole transport material poly(ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS)/V 2 O 5 . In this study, solution processed inorganic V 2 O
x
interlayer is incorporated into PEDOT:PSS for achieving improved film surface properties as well as optical and electrical properties. For example, the work function (WF) was changed from 5.1 to 5.4 eV. A remarkably high PCE of 17.5% with nearly free hysteresis and a stabilized efficiency of 17.1% have been achieved. Electronic impedance spectra (EIS) demonstrate a significant increase in the recombination resistance after introducing the interlayer, associated with the high V
oc output value of 1.05 V. Transient photocurrent and photovoltage measurements indicate that a comparable charge transport process and an inhibited recombination process occur in the PSC with the introduction of the V 2 O
x
interlayer.
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JOURNAL OF MATERIALS SCIENCE
·
2016
·Vol. 51
·期 21
·9625-9637
·
IF 2.302
Huang Qiang,Liu Meiying,Guo Ren,Mao Liucheng,Wan Qing,Zeng Guangjian,Huang Hongye,Deng Fengjie,Zhang Xiaoyong,Wei Yen
In this study, a facile surface functionalization method was applied to synthesize poly-levodopa (PDOPA)-modified silica nanocomposites (denoted as SiO 2 -PDOPA). The adsorption capacity of SiO 2 -PDOPA was found to be higher than that of unmodified SiO 2 NPs. The successful preparation of SiO 2 -PDOPA was confirmed by Fourier transform infrared spectroscopy, transmission electron microscopy, and thermo gravimetric analysis. The adsorption behavior was investigated using SiO 2 -PDOPA as adsorbents and Cu 2+ as a model heavy metal pollutant. Various adsorption parameters, including contact time, solution pH, temperature, and initial Cu 2+ concentrations were studied. The results showed that pH could markedly affect the adsorption process of SiO 2 -PDOPA to Cu 2+ . The optimum pH for Cu 2+ adsorption was found to be 7.0. The adsorption kinetic data were analyzed using pseudofirst-order, pseudosecond-order, and intraparticle diffusion
models. The adsorption isotherms could be described by Langmuir and Freundlich isotherm models. The fitting
results showed that the adsorption kinetics and isotherms were better
described by the pseudosecond-order and Langmuir model, respectively. The values of thermodynamics constants, including entropy change (Δ S
0 ), enthalpy change (Δ H
0 ), and Gibbs free energy (Δ G
0 ) were determined at different temperatures. Results suggested that the adsorption
process of SiO 2 -PDOPA to Cu 2+ is a feasible, endothermic, and spontaneous process.
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