ANALYTICA CHIMICA ACTA
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2016
·
IF 4.712
Pei Liu,Kexin Zhang,Ranran Zhang,Huanshun Yin,Yunlei Zhou,Shiyun Ai
Abnormal level of DNA methyltransferase (MTase) – mediated DNA methylation is closely related with cancer and bacterial diseases. Herein, a novel strategy based on the keypad lock of duplex DNA modified meso-SiO 2 @Fe 3 O 4 was developed for colorimetric assay of Dam MTase activity. When the Dam MTase was introduced, the duplex DNA can be methylated at a palindrome sequence of 5′-GATC-3′ and cleaved by the methylation-sensitive restriction endonuclease Dpn I. Due to the instability of the newly formed DNA fragment, the hybrid will separated into a single-stranded DNA. Then the keypad lock will open, and the catalytic reaction of TMB and H 2 O 2 can be initiated through the pores of meso-SiO 2 @Fe 3 O 4 , and a high color signal can be clearly observed by the naked eye. Contrarily, without Dam MTase, the catalytic reaction will not be initiated, and result no color signal. The proposed method exhibited a wide dynamic range with a low detection limit of 0.73 U/mL. Additionally, this way can be performed in human serum with satisfying recovery. And the inhibition of Dam MTase can also be well demonstrated by using paclitaxel as a model. Therefore, the designed way not only provides a platform for monitoring Dam MTase activity, but also useful for further application in disease diagnosis and drug discovery.
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PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2017
·
IF 3.133
Liuting Shi,Jia Hu,XuDong Lin,Liang Fang,Fang Wu,Jiao Xie,FanMing Meng
Composite coatings consisting of polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE) and 40 nm silicon dioxide (SiO 2 ) nanoparticles (PPS-PTFE/SiO 2 ) with SiO 2 in the range of 0–4 g/l were successfully prepared on AZ31 Mg alloys by a simple spray process. The morphology, composition, water contact angle (WCA), wear behavior and corrosion properties of the composite coatings were measured by using SEM, FT-IR, OCA20, sandpaper abrasion and electrochemical workstation, respectively. Effects of SiO 2 content on the wear behavior and corrosion properties of the coatings were studied. It is found that micro-sized protrusions distribute on the surface of the coatings, and a fibrous-network structure of PTFE arranges on the protrusions. WCAs of the PPS-PTFE/SiO 2 (0–4 g/l) coating are in the range of (152°–145.5°) ± 0.3° and the sliding angles (SAs) are less than 5°. The WCAs of the un-abraded and 10 m-abraded-on-sandpaper PPS-PTFE/SiO 2 (4 g/l) coating are 145.5°±0.3° and 142.5°±0.3°, respectively, implying the PPS-PTFE/SiO 2 coating is a robust superhydrophobic one with good wear resistance. Due to the superhydrophobic characteristics, the PPS-PTFE-based coatings show superior corrosion resistance in 3.5 wt% NaCl solution to pristine AZ31 Mg alloys. Owing to the excellent superhydrophobicity, wear resistance and corrosion resistance properties, the robust PPS-PTFE/SiO 2 coating is regarded to possess great potential to be applied in automobiles and navigation industries in future.
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高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Zhiping Zhou,Haiqin Ying,Yanyan Liu,Wanzhen Xu,Yanfei Yang,Yu Luan,Yi Lu,Tianshu Liu,Shui Yu,Wenming Yang
This paper demonstrates a facile method to synthesize surface molecular imprinting polymer (MIP) on SiO 2 -coated CdTe QDs for selective detection of sulfadimidine (SM 2 ). The fluorescent MIP sensor was prepared using cadmium telluride quantum dots (CdTe QDs) as the material of fluorescent signal readout, sulfadimidine as template molecule, 3-aminopropyltriethoxysilane (APTES) as functional monomer and tetraethyloxysilane (TEOS) as cross-linking agent. The CdTe cores were embed in the silicon shells by a sol-gel reaction and then the molecular imprinting layers were immobilized on the surface of the SiO 2 -coated CdTe QDs. Under the optimized conditions, the relative fluorescent intensity weakened in a linear way with the increasing concentration of sulfadimidine in the range of 10–60 μmol L −1 . The practical application of the fluorescent MIP sensor was evaluated by means of analyzing sulfadimidine in the real milk samples. The recoveries were at the range of 90.3–99.6% and the relative standard deviation (RSD) ranged from 1.9 to 3.1%, which indicates the successful synthesis of the fluorescent MIP sensor. This sensor provides an alternative solution for selective determination of sulfadimidine from real milk samples.
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高影响因子
CHINESE CHEMICAL LETTERS
·
2016
·
IF 1.947
Ting-Ting Zhang,Jing-Yang Jiang,Yan-Hua Wang
Various supported Pt-Pb bimetallic catalysts were prepared and applied for the catalytic conversion of nitrobenzene to p -aminophenol in the environmentally benign pressurized CO 2 /H 2 O system. Among the bimetallic catalysts prepared, Pt-Pb/SiO 2 is the best and nitrobenzene could be converted to p -aminophenol with a selectivity as high as 82% when the reaction was carried out using this catalyst at 110 °C under 5 MPa CO 2 and 0.2 MPa H 2 .
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高影响因子
ENERGY & FUELS
·
2016
·
IF 2.835
Lixia Geng,Shuangfeng Wang,Tingyu Wang,Ruilian Luo
A novel nanencapsulated phase change material (NEPCM) was fabricated via the self-assembly method with n-dodecanol as the core and SiO2 derived from sodium silicate as the shell. The as-prepared nanocapsules with different core/shell ratios were investigated systematically. Scanning electron microscopy and transmission electron microscopy photographs indicated that the products had a nearly spherical and compact surface with nanometer size. Fourier transform infrared spectroscopy and X-ray diffraction confirmed that SiO2 was successfully encapsulated upon n-dodecanol. Differential scanning calorimetry results showed that the NEPCMs exhibited similar phase change characteristics to pristine n-dodecanol, which melted at 21.03 °C with a latent heat of 116.7 J/g and solidified at 19.58 °C with a latent heat of 114.6 J/g. Thermogravimetric analysis and thermal cycle tests revealed that the nanocapsules had good thermal stability. In conclusion, the prepared nanocapsules have great potential for thermal energy storage and building energy conservation as a result of their facile synthesis process, low cost, and excellent thermal properties.
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高影响因子
Journal of Materials Chemistry B
·
2016
·Vol. 4
·期 25
·4402-4409
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IF 4.872
Nan Lv,Zhigang Wang,Wenzhi Bi,Guangming Li,Jilin Zhang,Jiazuan Ni
The novel chloro(dimethyl)octylsilane (C8)-functionalized [CeO2//SiO2] Janus fibers (denoted CeO2//SiO2-C8) have been successfully prepared by electrospinning technique and subsequent modification. The CeO2//SiO2-C8 Janus fiber composed of the side-by-side CeO2 fiber and SiO2 fiber modified by C8 is endowed with separate affinity sites and hydrophobic chains. It has a relatively high specific surface area of 127.4 m2 g−1 with an average pore size of 4.1 nm. The potential of CeO2//SiO2-C8 Janus fibers for the selective capture and individual MS detection of low-abundance endogenous peptides and phosphopeptides from the tryptic protein digest and human serum real sample was explored and evaluated for the first time. The experimental results demonstrate that the CeO2//SiO2-C8 Janus fiber can selectively extract phosphopeptides in virtue of high selective affinity of CeO2 to phosphate groups and enrich low-abundance peptides on account of the strong hydrophobic interaction of C8 chains. Moreover, the enrichment performance of the CeO2//SiO2-C8 probe is superior to that of commercial products (e.g. TiO2 nanoparticles and ZipTipC18 pipette tips) available. Overall, the efficient enrichment capability of CeO2//SiO2-C8 Janus fibers makes them a prospective candidate for the capture of low-abundance endogenous peptides and phosphopeptides from complex biological samples for individual MS detection.
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PubMed
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 32
·27039-27046
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IF 3.289
Honglin Yao,Qianqian Ding,Hongjian Zhou,Zhenfu Zhao,Gang Liu,Guozhong Wang
In this study, mesoporous amino-group functionalised iron/silica hollow spheres (Fe/SiO2–NH2 HSs) were successfully developed as a magnetic absorbent for the highly effective removal of Cr(VI) ions. The Fe/SiO2–NH2 HSs were synthesized using monodispersed silica colloids as a chemical template, followed by a one-pot hydrothermal treatment, hydrogen reduction and surface modification with an amino silane coupling agent. The Fe/SiO2–NH2 HSs have a diameter of ca. 950 nm and a shell thickness of ca. 60 nm, and the surfaces were composed of Fe and SiO2 units with amino functional groups. Meanwhile, the ferromagnetic property endowed them with easy recyclability for practical applications. The Fe/SiO2–NH2 HSs exhibited significantly improved ability to remove pollutant Cr(VI) and methyl orange. The removal percentage of Cr(VI) (8 mg L−1) could reach 98.3% in just 5 min using Fe/SiO2–NH2 HSs; however, only 10% of Cr(VI) were removed using the unmodified samples. XPS analysis suggested that the removal of Cr(VI) was attributed to the adsorption and reduction synergistic process of the Fe/SiO2–NH2 HSs. During the process, an electrostatic attraction occurred between the positively charged amino-groups and the negatively charged pollutant species in the aqueous solution, and adsorbed Cr(VI) ions were reduced to Cr(III) species by the iron of Fe/SiO2–NH2 HSs.
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高影响因子
ENERGY AND BUILDINGS
·
2017
·
IF 4.067
Zigeng Luo,Hua Zhang,Xuenong Gao,Tao Xu,Yutang Fang,Zhengguo Zhang
Phase change materials (PCMs) have great potential for the regulation of indoor temperature and building energy saving. In this study, capric acid-palmitic acid-stearic acid (CA-PA-SA) ternary eutectic mixture was impregnated into nano-silicon dioxide (nano-SiO 2 ) to prepare a form-stable composite PCM (CA-PA-SA/nano-SiO 2 ). The phase change temperature range of the composite PCM is 17.16 °C–26 °C, which is suitable for indoor thermal environment. The high latent heat value and the low thermal conductivity of the composite PCM are 99.43 kJ kg −1 and 0.08239 W (m K) −1 , which is helpful to stabilize the indoor temperature for a long time and improve human comfort. Furthermore, after 500 heating/cooling cycles, the composite PCM showed good thermal and chemical stability. The maximum CA-PA-SA mass fraction of the composite PCM was determined as high as 75 wt.%, with no melted CA-PA-SA seeping from the composite PCM. All the results indicated that the composite PCM is suitable for storing excess solar radiation and reducing the amount and rate of heat loss of buildings in the winter, which will help reduce building energy consumption.
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高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Tingting Liu,Hong Lei
Abrasive is one of the most important factors in chemical mechanical polishing (CMP). In order to improve the polishing qualities of sapphire substrates, the novel Nd 3+ -doped colloidal SiO 2 composite abrasives were prepared by seed-induced growth method. In this work, there were a series of condensation reactions during the synthesis process of Nd 3+ -doped colloidal SiO 2 composite abrasives and the silica cores were coated by shells (which contains SiO 2 , Nd 2 Si 2 O 7 and Nd(OH) 3 ) via chemical bonds and hydrogen bonds in the Nd 3+ -doped colloidal SiO 2 composite abrasives, which made the composite abrasives’ core-shell structure more sTable Scanning electron microscopy (SEM) showed that Nd 3+ -doped colloidal SiO 2 composite abrasives were spherical and uniform in size. And the acting mechanisms of Nd 3+ -doped colloidal SiO 2 composite abrasives on sapphire in CMP were investigated. Time-of-flight secondary ion mass spectroscopy (TOF-SIMS) analysis and X-ray photoelectron spectroscopy (XPS) analysis demonstrated that the solid-state chemical reactions between the shells (which contained SiO 2 , Nd 2 Si 2 O 7 and Nd(OH) 3 ) of Nd 3+ -doped colloidal SiO 2 composite abrasives and the sapphire occurred during the CMP process. Furthermore, Nd 3+ -doped colloidal SiO 2 composite abrasives exhibited lower surface roughness and higher material removal rate (MRR) than the pure colloidal SiO 2 abrasives in the same polishing conditions, which was attributed to the solid-state chemical reactions between shells of Nd 3+ -doped colloidal SiO 2 composite abrasives and sapphire.
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高影响因子
RSC Advances
·
2017
·Vol. 7
·期 12
·6911-6921
·
IF 3.108
Chunrong Ren,Xingeng Ding,Huiqin Fu,Wenqi Li,Huating Wu,Hui Yang
To remove heavy metals from aqueous solutions, amino-functionalized superparamagnetic CoFe2O4@SiO2 (CoFe2O4@SiO2–NH2) core–shell nanospheres were designed and constructed. In particular, well-defined CoFe2O4 nanoparticles (NPs) were synthesized by reverse co-precipitation. The shell of the CoFe2O4 NPs was composed of amorphous silica (SiO2), which had a thickness of ∼35 nm. Monodisperse CoFe2O4@SiO2 nanospheres grafted with more amino groups had a greater adsorption capacity and higher removal efficiency for heavy metal ions (Cd(II): 199.9 mg g−1, 99.96%; Cu(II): 177.8 mg g−1, 88.05%; Pb(II): 181.6 mg g−1, 90.79%). The effects of the pH, initial concentrations, reaction temperature and time on the adsorption of heavy metal ions by CoFe2O4@SiO2–NH2 were analyzed systematically. The adsorption process on the nanospheres was well described by the Langmuir model. The adsorption kinetics can be best fitted by the pseudo-second-order kinetics model. Analysis of a thermodynamic study of Cu(II) showed that the process of adsorption is spontaneous and endothermic in nature. Owing to the superparamagnetic properties with a high saturation magnetization value (32.92 emu g−1) of CoFe2O4@SiO2–NH2, the metal-loaded nanospheres can be quickly removed from an aqueous solution (30 s) by magnetic separation. Moreover, the nanospheres exhibited good reusability for up to five cycles. The results confirm that the monodisperse amino-functionalized CoFe2O4@SiO2 magnetic nanospheres could be a potential adsorbent for the effective and regenerable removal of heavy metals from aqueous solutions.
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高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Kai Liu,Fei Ding,Jiaquan Liu,Qingqing Zhang,Xingjiang Liu,Jinli Zhang,Qiang Xu
A cross-linking succinonitrile (SN)-based composite polymer electrolyte (referred to as “CLPC–CPE”), in which vinyl-functionalized SiO2 particles connect with trimethylolpropane propoxylate triacrylate (TPPTA) monomers by covalent bonds, was prepared by an ultraviolet irradiation (UV-curing) process successfully. Vinyl-functionalized SiO2 particles may react with TPPTA monomers to form a cross-linking network within the SN-based composite polymer electrolyte under ultraviolet irradiation. Vinyl-functionalized SiO2 particles as the fillers of polymer electrolyte may improve both the thermal stability of CLPC–CPE and interfacial compatibility between CLPC–CPE and electrodes effectively. There is no weight loss for CLPC–CPE until above 230 °C. The ionic conductivity of CLPC–CPE may reach 7.02 × 10–4 S cm–1 at 25 °C. CLPC–CPE has no significant oxidation current until up to 4.6 V (vs Li/Li+). The cell of LiFePO4/CLPC–CPE/Li has presented superior cycle performance and rate capability. The cell of LiFePO4/CLPC–CPE/Li may deliver a high discharge capacity of 154.4 mAh g–1 at a rate of 0.1 C after 100 charge–discharge cycles, which is similar than that of the control cell of LiFePO4/liquid electrolyte/Li. Furthermore, the cell of LiFePO4/CLPC–CPE/Li can display a high discharge capacity of 112.7 mAh g–1 at a rate of 2 C, which is higher than that of the cells assembled with other plastic crystal polymer electrolyte reported before obviously.
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PubMed
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 75
·47738-47745
·
IF 3.108
Kunquan Li,Xingrong Zeng,Xuejun Lai,Shengyong Chai
Fluorine-containing acrylates (FACs) with different glass transition temperature (Tg) were synthesized by solution copolymerization, and then the superhydrophobic coatings were fabricated based on the FAC, micro-SiO2 (M-SiO2) and nano-SiO2 (N-SiO2) particles through a two-step spray method. The prepared FAC was characterized by Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-NMR) and differential scanning calorimetry (DSC). The wetting behavior and surface morphology of the superhydrophobic coating were studied. The resistance and mechanism of the superhydrophobic coating against abrasion were also investigated. FTIR and 1H-NMR showed that the fluorinated-containing monomer had copolymerized with the acrylate monomers, and FACs with different Tg of about 74.2 °C, 24.5 °C, −7.7 °C and −29.5 °C were prepared. After coating with FAC/M-SiO2/N-SiO2 composite coating, the surface showed hierarchical structures with a roughness (Sa) of 1.23 mm, and became superhydrophobic with a water contact angle higher than 150° and a low sliding angle lower than 5°. Abrasion testing showed that the superhydrophobic coating fabricated based on the FAC polymer with low Tg had better abrasion resistance in comparison with that of the FAC polymer with high Tg. Meanwhile, the M-SiO2 in the composite coating could weaken the abrasion force to the surface micro roughness damage and acted as connections for the adhesion of N-SiO2 particles during abrasion, which ensured the binary micro/nano structures required for good hydrophobicity after abrasion.
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高影响因子
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