MICROCHIMICA ACTA
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2018
·Vol. 186
·期 1
·1-8
·
IF 5.705
Chen Hua-Ying,Guo Dan,Gan Zhen-Fei,Jiang Lei,Chang Shuai,Li Da-Wei
A surface-enhanced Raman scattering (SERS) based nanoprobe was developed for detection and imaging of endogenous peroxynitrite in living cells. The probe was fabricated by assembling 3-mercaptophenylboronic acid pinacol ester onto the surface of gold nanoparticles (AuNPs). The detection of peroxynitrite is accomplished via measurement of the changes in the SERS spectra (at 882 cm −1 ) that are caused by the reaction between probe and peroxynitrite. The probe has a fast response (<30 s), a 0.4 μM lower detection limit and a wide linearity range from 5.0 × 10 −7 to 1.0 × 10 −4 M. It is biocompatible and highly stable on storage and under various pH conditions. Both the reaction and the SERS signal are highly specific over other species. The nanoprobe was successfully applied to SERS imaging of peroxynitrite that is produced in macrophages under oxidative stress. Conceivably, the method has a most viable tool for use in studies on peroxynitrite-related physiological and pathological processes.
Schematic presentation of surface-enhanced Raman scattering (SERS) nanoprobes fabricated by assembling phenylboronate on gold nanoparticles (AuNPs) for detecting intracellular peroxynitrite (ONOO − ) via specific reaction-caused SERS changes.
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高影响因子
CELLULOSE
·
2018
·Vol. 26
·期 3
·2055-2074
·
IF 3.809
Li Hui,Wang Xin,He Yunqing,Peng Lincai
Abstract Oil/water separation is highly desired due to increasing industrial oily wastewater and frequent oil spill accidents. Here, superhydrophobic/superoleophilic paper was successfully fabricated by the combination of layer-by-layer (LBL) deposition of chitosan (CS) and hexadecyltrimethoxysilane (HMTS)- g -TiO 2 on paper surface and subsequent heat treatment. The formation of CS/HTMS- g -TiO 2 multilayers on modified papers was characterized. The wettability and physical strength of the modified papers were also examined. The paper modified with (CS/HTMS- g -TiO 2 ) 20 multilayers followed by heat treatment showed superhydrophobicity with a water contact angle of 167.4° and superoleophilicity with an oil contact angle of 0°. This paper had comparable tensile strength to that of original paper and excellent self-cleaning performance. The as-prepared paper could also effectively separate both immiscible oil–water mixtures and water-in-oil emulsions solely driven by gravity. The obtained paper exhibited stable recyclability, high environmental and mechanical durability. Therefore, this LBL-modified paper could be useful for oil spill cleanup and industrial oily wastewater treatment. Graphical abstract
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JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
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2018
·Vol. 319
·期 1
·115-121
·
IF 1.181
Chen Shunzhang,Shu Xiaoyan,Luo Fen,Dong Hao,Xu Chen,Li Bingsheng,Shao Dadong,Lu Xirui
To efficiently inhibit the diffusion of radioactive nuclides in soil that were left by nuclear emergency accidents, microwave sintering technology was used in this work to vitrify the simulated strontium contaminated soil. Four kinds of simulated strontium-contaminated soil could be successfully vitrified almost completely within 30 min without any additional components. Sr 2+ cations are immobilized into aluminosilicate glass network structure. In addition, the solubility of SrSO 4 in different soil is related to the element contents of aluminum and silicon. This work reveals a demonstration that beta-radioactive contaminated soil could be treated by microwave vitrifying.
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MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 10
·1-8
·
IF 5.705
Pang Jiawei,Lu Yuexiang,Gao Xinyu,Song Panshu,Yang Fengyi,Liu Yueying
A selective phosphorescent on-off-on probe with long decay lifetime has been designed for the detection of pyrophosphate ions (PPi). The detection scheme is based on the use of europium(III)-modulated Mn(II)-doped ZnS quantum dots capped with N-acetyl-L-cysteine. Both the aggregation of quantum dots and electron transfer induced by Eu(III) ions cause phosphorescence to be quenched (“off” state). Phosphorescence is, however, restored on addition of PPi to the system (“on” state). The effect is attributed to the removal of Eu(III) from the carboxy groups on the surface of the quantum dots owing to the stronger interaction between PPi and Eu(III). A linear relationship exists between phosphorescence intensity (best measured at excitation/emission wavelengths of 316/594 nm) and PPi concentration in the 400 nM to 6000 nM with a detection limit of 145 nM. An additional attractive feature is provided by the long-lived phosphorescence (1920 μs) of the quantum dots. It can be used to eliminate interference by short-lived fluorescence in biological samples by performing time resolved measurements. The probe was applied to the determination of PPi in spiked in urine samples and gave recoveries in the range from 98 to 105% with RSDs of <2.0%.
Schematic of a long-lived phosphorescent on-off-on probe for the sensitive and selective detection of pyrophosphate ions (PPi). It is based on the use of Eu(III)-modulated Mn(II)-doped ZnS quantum dots (QDs). Phosphorescence is quenched of QDs after the addition of Eu 3+ but restored after the addition of PPi.
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高影响因子
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
·
2019
·Vol. 26
·期 23
·23593-23602
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IF 2.914
Zhang Xiaohan,Huang Riheng,Li Ping,Ren Yuan,Gao Jianfa,Mueller Jochen F.,Thai Phong K
Wastewater-based epidemiology (WBE) has been widely used as a complementary method for estimating consumption of illicit drugs in the population. Temporal drug consumption estimates derived from WBE can provide important information for law enforcement and public health authorities in understanding changes in supply and demand of illicit drugs, but currently lacking in China. In this study, influent wastewater samples from a municipal sewage treatment plant in Guangzhou, China were collected for 8 weeks to investigate the temporal change in consumption of six illicit drugs in the catchment. The results indicated that methamphetamine and ketamine were the dominant illicit drugs in Guangzhou with the per capita use of 14.7–470.7 mg/day/1000 people and 64.9–673.7 mg/day/1000 people, respectively. No distinct weekly patterns were observed for illicit drug consumption in Guangzhou, indicating that drug users are likely to be regular ones. Further assessment about the impact of public holidays on the consumption behavior of drugs showed little impact for ketamine ( p = 0.689), but higher consumptions of methamphetamine ( p = 0.003) and cocaine ( p = 0.027) were observed during public holidays than the control period. The considerable decrease in drug consumption observed in October 2017 compared with January and May 2017 was possibly the consequence of law enforcement action.
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CHINESE JOURNAL OF POLYMER SCIENCE
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2019
·Vol. 37
·期 12
·1257-1266
·
IF 2.804
Li Ting,Zheng Tian-Ze,Guo Zhao-Xia,Xu Jun,Guo Bao-Hua
A well-defined quadruple hydrogen bonding strategy involving dimerization of 2-ureido-4[1 H ]-pyrimidone (UPy) units is innovatively designed to prepare polyureas with high overall mechanical properties. Three polyureas containing different amounts of UPy units were synthesized by replacing a portion of isophorone diisocyanate (IPDI) with a UPy-derived diisocyanate. The formation of quadruple hydrogen bonds in hard segments via UPy dimers was confirmed by nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR). The mechanical properties of the polyureas were evaluated by uniaxial tensile testing. Compared to the polyurea without UPy units, remarkable improvements in Young’s modulus, tensile strength, and toughness were simultaneously achieved when UPy units were incorporated. The mechanism behind the strong strengthening effect rooted in the stronger intermolecular forces among hard segments brought by the quadruple hydrogen bonds, which were stronger than the inherent bidentate and monodentate hydrogen bonds among urea groups, and the slower soft segmental dynamics reaveled by both increased T g and relaxation time of the soft segments. The mechanism behind the strong toughening effect was ascribed to more effective energy dissipation brought by the quadruple hydrogen bonds that served as stronger sacrificial bonds upon deformation. This work may offer new insight into the design of polyurea elastomers with comprehensively improved mechanical properties.
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KOREAN JOURNAL OF CHEMICAL ENGINEERING
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2019
·Vol. 36
·期 5
·729-739
·
IF 2.476
Pan Jiaying,Ou Zhimin,Tang Lan,Shi Hanbing
Racemic 1-phenylethylamine was resolved by enantiomer selective acetylation using Fe 3 O 4 -chitosan microsphere (CTS)-glutaraldehyde-lipase in a solvent-free system under an alternating magnetic field. Magnetic chitosan microspheres (Fe 3 O 4 -CTS) were prepared via chemical co-precipitation and cross-linked with lipase using glutaraldehyde to form Fe 3 O 4 -CTS-glutaraldehyde-lipase particles. The magnetic, physicochemical, and textural characteristics of Fe 3 O 4 -CTS-glutaraldehyde-lipase particles were assessed by Fourier transform infrared spectroscopy, X-ray diffraction, and scanning electron microscopy. The optimal immobilization conditions were 2.4 mg/mL lipase, 10 mg/mL Fe 3 O 4 -CTS-glutaraldehyde, pH 8.5, 35 °C, 3 h. The loading amount of lipase and the specific activity got to 132 mg/g carrier and 48 U/g. The optimal reaction conditions of the acylation reaction using Fe 3 O 4 -CTS-glutaraldehyde-lipase were 300 mmol/L 1-phenylethylamine, 150 mg immobilized lipase, 2 mL vinyl acetate, 12.6 ×g rotating speed, 40 °C, 8 h. The activity of the Fe 3 O 4 -CTS-glutaraldehyde-lipase particles and conversion were improved when they were exposed to an external alternating magnetic field. The optimum magnetic field was 12 Gs (500 Hz). The conversion, enantiomeric excess of ( R )- N -(1-phenylethyl)acetamide, and E value reached 41.8%, 98.4%, and 264, respectively. Fe 3 O 4 -CTS-glutaraldehyde-lipase could be reused seven times. A kinetic model of the immobilized lipase-catalyzed resolution of 1-phenylethylamine was set up based on the ping-pong bi-bi mechanism. The kinetic constants were V max =1.62×10 −2 mM/min, K A =2.84×10 −4 mM, and K B =5.8×10 −1 mM. The model data fit well with the experimental data.
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CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
·
2019
·Vol. 35
·期 3
·382-389
·
IF 1.071
Wang Chengke,Tan Rong,Li Jiangyu,Zhang Zexiang
A double magnetic separation-assisted fluorescence method was developed to rapidly detect ochratoxin A(OTA). The OTA aptamer functionalized magnetic nanomaterial(Fe 3 O 4 -Aptamer) and complementary DNA conjugated nitrogen-doped graphene quantum dots(NGQDs-cDNA) were used in this assay. Aptamer could hybridize with cDNA, which induced the NGQDs-cDNA to bind onto Fe 3 O 4 -Aptamer, and resulted in the fluorescence quenching of NGQDs. After the addition of OTA, the NGQDs-cDNA could release into the solution, and resulted in the recovery of fluorescence signal of NGQDs consequently. By utilizing the magnetic separation, the unbonded NGQDs-cDNA and residual Fe3O4-Aptamer were removed, which significantly increased the fluorescence signal intensity. OTA could be detected in the linear range of 10 nmol/L to 2000 nmol/L, with a limit of detection as 0.66 nmol/L. The advantages of this method include simple operation, good selectivity and high sensitivity, and this method can be used for the rapid detection of ochratoxin A in wheat and corn.
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JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2019
·Vol. 30
·期 12
·11108-11116
·
IF 2.195
Jiang Xishun,He Wenjun,Zheng Shaokang,Shi Yonghua,Sun Zhaoqi
A series of TiO 2 nanostructures with rutile phase were synthesized on arbitrary substrates of conductive transparent fluorine-doped tin oxide (FTO), tin-doped indium oxide (ITO), and glass at the low temperature of 150 °C by the hydrothermal method. The samples were characterized by XRD, SEM, TEM, XPS, UV–Vis absorption, and micro-Raman spectroscopy. The effects of growth substrates on the morphologies and optical properties of nanostructures were investigated. TiO 2 nanorods were grown on the FTO substrate, while TiO 2 nanoflowers were grown on the ITO and glass substrates, and the growth mechanism for these different nanostructures is discussed in detail. The results show that the TiO 2 nanorods can improve photocatalytic properties and photoelctrochemical (PEC) performance for its unique structure and optical properties. The TiO 2 nanorods exhibited a maximal photocatalytic rate of 4.42 min −1 and photocurrent density of 0.049 mA/cm 2 , which is about 1.52 and 3.03 times higher than those of TiO 2 nanoflowers grown on the ITO substrates, respectively. These findings are quite promising and encouraging for the use of TiO 2 nanoarrays in photocatalysis and energy applications.
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MICROCHIMICA ACTA
·
2019
·Vol. 186
·期 5
·1-8
·
IF 5.479
Zhao Chen,Hong Cheng-yi,Lin Zheng-zhong,Chen Xiao-mei,Huang Zhi-Yong
A specific and sensitive colorimetric aptasensor is described for the determination of Malachite Green (MG). It is exploiting the inhibition of the peroxidase-like activity of gold nanoparticles (AuNPs). The AuNPs act as enzyme mimics that catalyze the oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) by H 2 O 2 to yield a dark blue solution. The catalytic activity is inhibited by hexadecyl trimethyl ammonium ion, specifically by cetyltrimethylammonium bromide (CTAB), which causes the aggregation of AuNPs. If a (negatively charged) RNA-aptamer against MG is added, it binds to the positively charged CTAB and prevents aggregation. This enhances the enzyme mimicking activity of the AuNPs and leads to the formation of a dark blue solution. However, in the presence of MG, the aptamer binds to MG, and leads to the aggregation of AuNPs again. The aggregated AuNPs possess a light blue color. A colorimetric method (best performed at 650 nm) was work out that can detect MG in a concentration range from 10 to 500 nmol L −1 . The detection limit based on 3σ/k criterion is 1.8 nmol L −1 . The assay is highly specific and accurate. Recoveries from spiked real samples (aquaculture water) ranged from 80% to 120%.
Based on the inhibition of cetyltrimethyal ammonium ion and the enhancement of RNA-aptamer, the differences of the peroxidase-like activities of AuNPs can be greatly enlarged with and without MG, by which a colorimetric aptasensor can be constructed for the detection of Malachite Green (MG).
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高影响因子
COLLOID AND POLYMER SCIENCE
·
2018
·Vol. 297
·期 1
·125-132
·
IF 1.967
Li Chaowang,Xie Danhua,Pei Xiaomei,Song Binglei,Cui Zhenggang
Traditional tetrameric surfactants exhibit a variety of self-assembled aggregation behaviors and excellent rheological properties. In recent years, the use of non-covalent interactions to construct pseudo-oligomeric surfactants has attracted extensive attention. We constructed dynamic oleic acid-based pseudo-tetrameric surfactants through electrostatic interaction between tetrameric quaternary ammonium salts (3- n -3, n = 2, 3, 6, 8) and the environmentally friendly sodium oleate. The series of surfactants showed higher viscoelasticity with increasing concentration, which is similar to the traditional tetrameric surfactants. With the addition of the tetrameric salts, the zero-shear viscosity of the original sodium oleate solutions increased by a factor of more than 80,000. The rheological properties can be flexibly modulated by controlling the middle spacer length of the tetrameric quaternary ammonium salt. The wormlike micelles of dynamic oleic acid-based pseudo-tetrameric surfactants will expand the potential applications of ionic liquids in home care products, oil field stimulation fluids, and nanobiotechnology.
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Biotechnology for Biofuels
·
2018
·Vol. 11
·期 1
·1-14
·
IF 5.497
Wang Xiang,Dong Hong-Po,Wei Wei,Balamurugan Srinivasan,Yang Wei-Dong,Liu Jie-Sheng,Li Hong-Ye
Background Metabolic engineering has emerged as a potential strategy for improving microalgal lipid content through targeted changes to lipid metabolic networks. However, the intricate nature of lipogenesis has impeded metabolic engineering. Therefore, it is very important to identify the crucial metabolic nodes and develop strategies to exploit multiple genes for transgenesis. In an attempt to unravel the microalgal triacylglycerol (TAG) pathway, we overexpressed two key lipogenic genes, glycerol-3-phosphate acyltransferase (GPAT1) and lysophosphatidic acid acyltransferase (LPAT1), in oleaginous Phaeodactylum tricornutum and determined their roles in microalgal lipogenesis. Results Engineered P. tricornutum strains showed enhanced growth and photosynthetic efficiency compared with that of the wild-type during the growth phase of the cultivation period. However, both the cell types reached stationary phase on day 7. Overexpression of GPAT1 and LPAT1 increased the TAG content by 2.3-fold under nitrogen-replete conditions without compromising cell growth, and they also orchestrated the expression of other key genes involved in TAG synthesis. The transgenic expression of GPAT1 and LPAT1 influenced the expression of malic enzyme and glucose 6-phosphate dehydrogenase, which enhanced the levels of lipogenic NADPH in the transgenic lines. In addition, GPAT1 and LPAT1 preferred C16 over C18 at the sn-2 position of the glycerol backbone. Conclusion Overexpression of GPAT1 together with LPAT1 significantly enhanced lipid content without affecting growth and photosynthetic efficiency, and they orchestrated the expression of other key photosynthetic and lipogenic genes. The lipid profile for elevated fatty acid content (C16-CoA) demonstrated the involvement of the prokaryotic TAG pathway in marine diatoms. The results suggested that engineering dual metabolic nodes should be possible in microalgal lipid metabolism. This study also provides the first demonstration of the role of the prokaryotic TAG biosynthetic pathway in lipid overproduction and indicates that the fatty acid profile can be tailored to improve lipid production.
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