CHEMICAL RESEARCH IN CHINESE UNIVERSITIES
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2019
·Vol. 36
·期 5
·940-945
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IF 1.071
Shi Chengying,Yang Jiayu,Liu Yang,Wang Yanmiao,Xu Wenge,Xu Yiquan,Hu Wei,Liu Baijun
The surface-modified Al 2 O 3 particles were introduced into polyethylene(PE) to enhance the thermal conductivity, and PE/Al 2 O 3 cross-linked networks with improved thermal and mechanical properties were prepared through electron beam(EB) irradiation technology. The incorporation of reactive irradiation sensitizer was useful in fabricating a high degree of cross-linking(DC) PE networks under a low irradiation dose. In the PE sample containing 2% sensitizer, DC ca. 67.1% could be obtained under 60 kGy(1 kGy=1000 J/kg). EB-irradiation greatly improved the tensile stress of PE-based samples, and the tensile stresses of the samples with 0.2%—5% TMPTA(trimethylolpropane triacrylate) under 60 kGy were 24.61—27.77 MPa. All the EB-irradiated samples had higher Vicat softening temperatures than the samples without irradiation. After treatment at 120 kGy, the Vicat softening temperatures of PE-Al 2 O 3 -44/ TMPTA-2 increased from 127 °C to 130.4 °C. SEM images revealed that PE-Al 2 O 3 -50 samples with increased amount of Al 2 O 3 particles showed a conduction “pathway,” and thermal conductivity reached 0.67 W/(m·K). Thus, high-performance pipes were successfully extruded, which could satisfy the static hydraulic blasting test and exhibit improved thermal conduction capability.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2019
·Vol. 411
·期 29
·7857-7868
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IF 3.286
Luo Danqiu,Chen Huayun,Zhou Pei,Tao Han,Wu Yuangen
A novel colorimetric sensing platform based on the peroxidase activity of hemin regulated by oligonucleotide and pesticide was reported for the ultrasensitive and selective detection of isocarbophos. Oligonucleotides can accumulate on the surface of hemin in acid condition and temporarily inhibit its catalytic activity, which results in the loss of one electron of TMB molecule and produce the blue products. With the addition of isocarbophos, the pesticide molecules can interact with oligonucleotides to form some complexes, which relieve the inhibition of ssDNA to hemin and further enhance its catalytic activity. Thus, the TMB molecules are further oxidized to lose another electron and produce the yellow product in a few minutes, which has the characteristic absorption peak at 450 nm. The color change of the sensing system is related to the amount of isocarbophos, so this method can quickly discriminate whether the target pesticide exceeds the maximal residue limit just by naked eyes. To improve the performance of sensing platform, some important parameters like buffer condition and ssDNA have been investigated, and the peroxidase activity of hemin was further studied to verify the catalytic mechanism. The proposed sensing platform has a detection limit as low as 0.6 μg/L and displays good selectivity against other competitive pesticides. Moreover, the developed sensing platform also exhibits favorable accuracy and stability, indicating that it has potential applications in the detection of pesticide residues in agricultural products.
A novel colorimetric sensing platform based on oligonucleotides and pesticide regulation; the peroxidase catalytic activity of hemin was firstly reported for the ultrasensitive and selective detection of isocarbophos pesticide.
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FIBERS AND POLYMERS
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2019
·Vol. 20
·期 12
·2654-2664
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IF 1.439
Li Qiu,Zhang Ai-ling,Zhang Meng,Li Fang-fang,Wang Song,Li San-xi,Li Yong-jiang,Sun Ze-fei
Abstract: Methoxy polyethylene glycol acrylate (MPGA) was electrochemical polymerized on carbon fiber (CF) by using cyclic voltammetry (CV) to enhance the surface properties of CF. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetry analysis (TGA) investigations confirmed that MPGA electropolymerized on CF (MPGA-CF) was obtained. The low frequency capacitance of MPGA-CF (C LF =5.85 mF·cm -2 ) was higher than CF(C LF =4.75 mF·cm -2 ) based on the result of electrochemical impedance spectroscopy(EIS) and the data obtained fitted with an R(Q(R(Q(R(CR))))) equivalent circuit model. Contact angle experiment showed that the contact angle between water and MPGA-CF is significantly lower than that between water and CF. Mechanical experimental results indicated that the interlaminar shear strength (ILSS) of MPGA-CF/epoxy resin composites (32.24 MPa) has improved by 134.81 % compare with the CF/epoxy resin composites (13.73 MPa), which significantly enhanced interfacial properties of epoxy resin composites.
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RESEARCH ON CHEMICAL INTERMEDIATES
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2019
·Vol. 46
·期 1
·533-545
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IF 2.064
Zhou Quan,Qian Le,Pan Qianqian,Si Guanqing,Qi Zhaopeng,Zheng Yuchuan,Li Changjiang
In this paper, a novel chemosensor (named L1) for Fe 3+ based on the rhodamine 6G and o -vanillin has been synthesized, which can selectively recognize Fe 3+ . The L1 solution showed a distinguishable colour change by naked eye, and the fluorescence turns on response after the addition of Fe 3+ . In addition, the experimental results showed that the spirocyclic of L1 was opened by cooperation between L1 and Fe 3+ , and then the fluorescence emission after excitation of the mixture solution was detected with the change in solution colour. The complexation coefficient of L1 towards Fe 3+ was 1:1. Furthermore, L1 for Fe 3+ sensing had a remarkable low detection limit of 427 nM (UV) and 130 nM (fluorescence), which is far below the drinking water standards (0.3 mg/L) of China. Meanwhile, the in vivo imaging and cell viability assay experiments demonstrated that L1 could be used for sensing Fe 3+ in vivo.
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Journal of Food Measurement and Characterization
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2019
·Vol. 14
·期 2
·658-667
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IF 1.415
Zhao Yan,Song Yuying,Zhang Yuanyi,Fan Yuxia,Lai Keqiang
Malachite green (MG) is a banned fish drug, but is often found in various aquatic food products. In this study, Au nanoparticles (NPs) were incorporated with graphene oxide (GO) to fabricate Au NPs-GO hybrid films as surface enhanced Raman scattering (SERS) substrate for MG detection. The enhancement effect of the hybrid substrate for SERS signal of MG as influenced by GO concentration, size of Au NPs and pretreatment method for quartz sheets were evaluated. The optimal Au NPs-GO substrate was used to detect MG in fish muscle with SERS technology. The lowest detectable concentration for MG standard solution was 0.01 ng/mL, and the concentration of 0.25 ng/g could be detected in the muscle extracts of two different fish. SERS combined with Au NPs-GO hybrid substrate shows great potential for detection of trace amounts of MG in aquatic products.
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CLAYS AND CLAY MINERALS
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2019
·Vol. 67
·期 4
·325-333
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IF 1.835
Guo Yu-Hua,Pan Guo-Xiang,Xu Min-Hong,Wu Tao,Wang Yong-Ya
Adsorption desulfurization is a potential new method for deep desulfurization of fuel oil. The development of adsorbents with high adsorption capacity and selectivity is the core of deep adsorption desulfurization. The adsorption behavior of thiophene in MCM-41 mesoporous materials modified by various metal ions was studied in order to understand the adsorption desulfurization process of molecular sieves. The Fe-, Co-, and Zn-modified MCM-41 materials were prepared using a one-step in situ hydrothermal synthesis method. The modified MCM-41 molecular sieves maintained the mesoporous structure, and the metal ions had specific dispersion on the surface of the molecular sieves. Adsorption of thiophene on the surfaces of molecular sieves had both physical and chemical characteristics. The adsorption desulfurization performance of the modified molecular sieve was superior to that of the pure silica molecular sieve. In the simulated gasoline with sulfur content of 220 μg/g, when the amount of adsorbent used was 100 mg, the adsorptive desulfurization performance tended to be in equilibrium, and the optimum adsorption temperature was 30°C. Fe-MCM-41 and MCM-41 molecular sieves reached adsorption equilibrium after ~60 min, but the desulfurization rate of Co-MCM-41 and Zn-MCM-41 still increased slightly. The kinetic simulation results indicated that the pseudo-second-order kinetics adsorption model described well the adsorption process of thiophene on molecular sieves. The molecular sieve Fe-MCM-41 had the best desulfurization performance with an equilibrium adsorption capacity of 14.02 mg/g and the desulfurization rate was ~90%.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2019
·Vol. 411
·期 22
·5809-5816
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IF 3.286
Wei Xiao,Chen Hui
A novel ratiometric fluorescence molecularly imprinted sensor based on a dual-emission quantum dot hybrid was fabricated and used as an alternative analytical tool for the detection of tetracycline. In the synthesis process, red-emitting quantum dots (r-QDs) and green-emitting quantum dots (g-QDs) were modified by two different methods. Afterward, a stepwise precipitation polymerization imprinting reaction was performed to prepare the novel ratiometric fluorescence molecularly imprinted sensor (MIP–g/r-QD sensor). The MIP–g/r-QD sensor integrated the advantages of molecularly imprinted polymers and ratiometric fluorescence probes. The specific recognition sites in the polymer layers could adsorb tetracycline molecules, and then they caused fluorescence quenching behavior of g-QDs via an electron transfer process. Under the optimal conditions, a linear relationship was obtained covering the range from 10 to 160 μmol/L, with a correlation coefficient of 0.9976 and a high imprinting factor of about 3.3. Moreover, the novel MIP–g/r-QD sensor was successfully applied to detect tetracycline in milk samples. This work provides a new way to fabricate an efficient ratiometric fluorescence molecularly imprinted sensor based on quantum dots for convenient, fast, and highly selective and sensitive detection of organic molecules.
A novel ratiometric fluorescence molecularly imprinted sensor based on a dual-emission quantum dot hybrid was fabricated and used as an alternative analytical tool for the detection of tetracycline. AIBN azoisobutyronitrile, EGDMA ethylene glycol dimethacrylate, KH-570 3-(methacryloyloxy)propyltrimethoxysilane, OVDAC octadecyl-4-vinylbenzyldimethylammonium chloride, PDDA poly(diallyldimethylammonium chloride), QD quantum dot, TEOS tetraethoxysilane
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Nature Communications
·
2019
·Vol. 10
·期 1
·1-10
·
IF 11.878
Xia Qing,Chen Zixuan,Xiao Pengwei,Wang Minxuan,Chen Xueqin,Zhang Jian-Rong,Chen Hong-Yuan,Zhu Jun-Jie
Measurement of electron transfer at single-molecule level is normally restricted by the detection limit of faraday current, currently in a picoampere to nanoampere range. Here we demonstrate a unique graphene-based electrochemical microscopy technique to make an advance in the detection limit. The optical signal of electron transfer arises from the Fermi level-tuned Rayleigh scattering of graphene, which is further enhanced by immobilized gold nanostars. Owing to the specific response to surface charged carriers, graphene-based electrochemical microscopy enables an attoampere-scale detection limit of faraday current at multiple individual gold nanoelectrodes simultaneously. Using the graphene-based electrochemical microscopy, we show the capability to quantitatively measure the attocoulomb-scale electron transfer in cytochrome c adsorbed at a single nanoelectrode. We anticipate the graphene-based electrochemical microscopy to be a potential electrochemical tool for in situ study of biological electron transfer process in organelles, for example the mitochondrial electron transfer, in consideration of the anti-interference ability to chemicals and organisms.
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Environmental Chemistry Letters
·
2019
·Vol. 18
·期 1
·237-241
·
IF 4.617
Zhao Xiaodan,Wu Ying,Xing Danying,Ren Zhaojin,Ye Lingfeng
Sulfate radicals (SO 4 ·− ) are highly efficient for the degradation organic pollutants. SO 4 ·− can be produced by activation of sulfites, yet actual heterogeneous activators exhibit a lower reactivity for activation of sulfite to SO 4 ·− at pH 7.0–8.0. Here we hypothesized that zero-valent copper can activate sulfite under mild conditions. We tested the reaction with iohexol, diatrizoate, atrazine, benzoic acid, and p -chlorobenzoic acid contaminants. Reactive radicals were identified by electron paramagnetic resonance, fluorescence spectrometry, and radical scavenging experiments. Results show up to 90% abatement of contaminants by combining sulfite with zero-valent copper at pH 8.0. Moreover, zero-valent copper maintains a crystalline stability and satisfactory reusability with iohexol abatement efficiency up to 80% after five runs.
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Microbiome
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2019
·Vol. 7
·期 1
·1-16
·
IF 10.465
Zhang Yuan,Huang Rongrong,Cheng Mengjing,Wang Lirui,Chao Jie,Li Junxu,Zheng Peng,Xie Peng,Zhang Zhijun,Yao Honghong
Background Inflammasomes have been found to interact with the gut microbiota, and this effect is associated with depression, but the mechanisms underlying this interaction have not been elucidated in detail.Results The locomotor activity of NLRP3 KO mice was significantly greater than that of their WT littermates, while cohousing and transplantation of the NLRP3 KO gut microbiota avoid the effects of NLRP3 KO on the general locomotor activity at baseline. Meanwhile, transplantation of the NLRP3 KO microbiota alleviated the CUS-induced depressive-like behaviors. The compositions of the gut microbiota in NLRP3 KO mice and WT mice were significantly different in terms of the relative abundance of Firmicutes, Proteobacteria, and Bacteroidetes. Fecal microbiota transplantation (FMT) from NLRP3 KO mice significantly ameliorated the depressive-like behavior induced by chronic unpredictable stress (CUS) in recipient mice. Given the correlation between circular RNA HIPK2 (circHIPK2) and depression and the observation that the level of circHIPK2 expression was significantly increased in CUS-treated mice compared with that in the control group, further experiments were performed. FMT significantly ameliorated astrocyte dysfunction in recipient mice treated with CUS via inhibition of circHIPK2 expression.Conclusion sOur study illustrates the involvement of the gut microbiota-circHIPK2-astrocyte axis in depression, providing translational evidence that transplantation of the gut microbiota from NLRP3 KO mice may serve as a novel therapeutic strategy for depression.
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JOURNAL OF NANOPARTICLE RESEARCH
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2019
·Vol. 21
·期 8
·1-12
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IF 2.009
Lu Jiayu,Xu Yanyan,Liu Wei,Wu Zhaoliang,Li Na,Shu Ting
The recovery of nano-catalysts from organic wastewater is still one of the most significant problems in the catalytic industry. In this work, froth flotation was used to solve this problem. CuO nano-particles were considered as the desired materials. First, four surfactants were screened for determining a suitable collector through comparing their foam properties and capture capacity to CuO nano-particles. Subsequently, froth flotation was performed by using cocamidopropyl betaine (CAB) as the collector. Under the suitable operation conditions, the enrichment ratio and recovery percentage of CuO nano-particles reached as high as 20.52 and 91.50%, respectively. Finally, the size distribution and morphology of CuO nano-particles before and after froth flotation were characterized. Experimental results indicated that the dispersibility of the recovered CuO nano-particles after froth flotation was better than that of the commercial CuO nano-particles due to the existence of surfactant molecules around the nano-particle surface. This work is expected to provide a new insight into the effective recovery of nano-catalysts from the downstream industrial effluent and to facilitate the industrialization of froth flotation in the green catalytic industry.
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JOURNAL OF MATERIALS SCIENCE
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2019
·Vol. 54
·期 16
·11243-11253
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IF 3.442
Rao Chaohui,Guo Xia,Li Min,Sun Xiaoqing,Lian Xiaojie,Wang Huifang,Gao Xianghua,Niu Baolong,Li Wenfeng
The development of high drug loading and sustained release nanoparticles by simple and economical methods is significant for the treatment of diseases. Amorphous calcium carbonate (ACC) is an ideal drug delivery system because of its excellent pH responsiveness, biocompatibility and biodegradability. In this work, ACC nanoparticles were successfully precipitated in ethanol–calcium solutions using ammonium carbonate as the internal source of CO 2 , which exhibited a relatively narrow size distribution in range of 10–200 nm. The microscopic morphology, amorphous characters, porous structure and thermal behavior of resultants were investigated by electron microscopy, Fourier-transform infrared spectroscopy, Brunauer–Emmett–Teller and thermogravimetric analysis, respectively. In vitro drug release assay showed that ACC nanoparticles had high loading capacity of curcumin (Cur) and favorable drug release properties. Furthermore, ACC-Cur showed excellent abilities to scavenge free radicals, protect Cur stability and damage A549 cells, providing a broadened space for the applications of this material in the fields of biomedical or food.
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