TALANTA
·
2018
·
IF 4.244
Junxing Hao,Kangbing Wu,Chidan Wan,Yong Tang
Developing reliable and feasible electrochemical sensors for the detection of 8-hydroxy-2′-deoxyguanosine (8-OHdG) is important because the urinary level of 8-OHdG is related to cancer disease. Moreover, the co-existed uric acid (UA) as an interference severe affects the sensitive detection of 8-OHdG. Herein, sensitive monitoring of 8-OHdG was conducted using a nanocomposite of reduced graphene oxide (rGO) and ZnO nanoparticles (ZnO@rGO) as the sensing material. This nanocomposite was prepared via in-situ reduction of GO with Zn powders. Compared with those obtained on the unmodified glassy carbon electrode (GCE) and GO modified GCE (GO/GCE) the oxidation signals of 8-OHdG are significantly enhanced on the ZnO@rGO nanocomposite coated GCE (ZnO@rGO/GCE). Moreover, uricase has been employed successfully to eliminate the interferences of UA. A large amount of UA did not affect the oxidation signals of trace level of 8-OHdG. The linear range for the detection of 8-OHdG using ZnO@rGO/GCE was from 5.0 to 5000.0 nM. The detection limit was 1.25 nM calculated from a three-signal-to-noise ratio. The developed monitoring system is sensitive and selective for the determination of 8-OHdG and thus useful in practical applications, such as for the monitoring of 8-OHdG in the clinic urine samples.
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PubMed
高影响因子
ANALYST
·
2018
·Vol. 143
·期 12
·2837-2843
·
IF 3.864
Xueping Zhang,Qingqing Wang,Jing Li,Liang Huang,Dengbin Yu,Shaojun Dong
In this work, a novel electrochemical sensor for Cd(II) detection with differential pulse anodic stripping voltammetry (DPASV) is fabricated based on hollow ZnO@nitrogen-doped carbon (H-ZnO@NC) polyhedra, which are prepared from ZIF-8 via in situ tannic acid etching and a subsequent calcination process. The as-obtained H-ZnO@NC exhibits a polyhedral morphology with a well-defined hollow structure and a uniform distribution of elements C, N, O, and Zn in the shell. The unique structure of H-ZnO@NC can provide an enlarged surface area and abundant active sites. Moreover, ZnO has a strong affinity for heavy metals, which can enhance the adsorption capacity of H-ZnO@NC for Cd(II) in the accumulation step of stripping voltammetry, and thus improve the electrochemical sensing performances. As expected, the H-ZnO@NC-based sensor achieves a wide linear range of 0.3–300 μg L−1, a low detection limit of 0.1 μg L−1 (S/N = 3), and exhibits good selectivity as well as high stability and reproducibility. Moreover, the proposed electrochemical sensor can be applied for the determination of Cd(II) in real water samples, obtaining satisfactory results.
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高影响因子
CORROSION SCIENCE
·
2018
·
IF 4.862
Liangliang Xiong,Jianhua Liu,Mei Yu,Songmei Li
A two-dimensional nanocomposite, salicylaldehyde@ZIF-8/GO (SZG), was synthesized by anchoring the ZIF-8 nanoparticles containing the inhibitor salicylaldehyde (SA) on GO nanosheets for corrosion protection of AA2024 aluminum alloy. Its stimuli-responsive release of SA under acid and Al 3+ cations conditions was proved by UV–vis. Electrochemical impedance spectroscopy demonstrated that SZG nanocomposites prominently improved the protection properties of PVB coating by enhanced passive and active protection compared with the controlled samples. The enhanced passive protection derived from the two-dimensional structure of SZG, while inhibitor SA acted the active protection. Quantum chemical calculation clearly clarified the release and inhibition mechanisms of SA.
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高影响因子
JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
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2014
·
IF 2.063
Zhigang Jia,Lulu Yang,Jianhong Liu,Qiuze Wang,Rongsun Zhu
Magnetic carbon spheres have been successfully prepared by the synchronous carbonation and activation of the 8-quinoliolato Fe(III) complexe with sphere morphology, which has been synthesized by solovthermal method. The obtained composite possesses relatively even pore diameter of 3.8 nm, high surface area of 335.59 m 2 /g with 52.67 wt.% Fe 3 O 4 coated, and a saturation magnetization (Ms) of 35.27 emu/g. Dye separation performance of the magnetic carbon spheres is investigated using methylene orange and methylene blue as modle. The resluts show that the maxium adsorption capacity for methylene orange and methylene blue is 128.70 mg g −1 and 151.29 mg g −1 , respectively, and the process can rapidly reach adsorption equilibrium within 5 min, which is important for the application of the as-prepared magnetic carbon spheres.
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高影响因子
SOLID STATE SCIENCES
·
2015
·
IF 1.839
Yan-Jing Gu,Bing Yan
A series of organic–inorganic hybrid materials were prepared by linking lanthanide (Eu 3+ , Sm 3+ ) complexes to mesoporous SBA-15/SBA-16 through 8-hydroxybenz[de]anthracen-7-one modified silane (HBA-Si) as linker. The physical characterizations of these hybrids revealed that they all have high surface area, uniformity in mesostructure. The luminescence properties of these covalently bonded materials (denoted as Ln(HBA-SBA-15) 3 phen and Ln(HBA-SBA-16) 3 phen) were compared with ternary complexes (Ln(HBA) 3 phen) (Ln = Eu, Sm). Eu(HBA-SBA-15(16)) 3 phen hybrids display better thermal stability, whose luminescent lifetimes and quantum efficiencies were matchable with those of Eu(HBA) 3 phen complex in spite of its much lower effective condensation of Eu 3+ species. In addition, the luminescent performance of functionalized SBA-15 hybrids was more favorable than that of functionalized SBA-16 hybrids, revealing that SBA-15 was a better host material for lanthanide complex than mesoporous silica SBA-16.
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高影响因子
MICROCHEMICAL JOURNAL
·
2015
·
IF 2.746
Zhirong Zou,Shanling Wang,Jia Jia,Fujian Xu,Zhou Long,Xiandeng Hou
In this work, magnetic Fe 3 O 4 @ZIF-8 core-shell nanoparticles (MNPs) were employed for effective adsorption of inorganic arsenic for preconcentration , with adsorption mechanism thoroughly discussed. The adsorbed inorganic arsenic was easily separated by a magnet along with the MNPs from the sample matrix, with possible matrix interference eliminated. The MNPs were then completely dissolved in hydrochloric acid prior to the determination of inorganic arsenic by hydride generation-atomic fluorescence spectrometry. The Fe 3 O 4 @ZIF-8 MNPs were prepared with a facile step-by-step assembly method in aqueous solution at room temperature . Under the optimized conditions, the sensitivity for inorganic arsenic determination was significantly increased through preconcentration, with satisfactory analytical merits obtained.
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高影响因子
JOURNAL OF ETHNOPHARMACOLOGY
·
2015
·
IF 2.998
Hui-Hui Xiao,Quan-Gui Gao,Ming-Xian Ho,Yan Zhang,Ka-Chun Wong,Yi Dai,Xin-Sheng Yao,Man-Sau Wong
Ethnopharmacological relevance Sambucus williamsii Hance (SWH), which belongs to the Caprifoliaceae family distributed in various regions of China, Korea and Japan, has been used as a folk medicine for treatment of bone and joint diseases in China for thousands of years. In previous studies, SWH was shown to possess anti-osteoporosis, healing fracture, anti-inflammatory and analgesic activities. Our previous studies showed that SWH extract effectively suppressed ovariectomy-induced increase in bone turnover and improved bone mineral density and bone biomechanical strength in rats as well as in mice. An 8- O -4′ norlignan, (7 R ,8 S )-1-(4-hydroxy-3-methoxyphenyl)-2-[4-(3-hydroxypropyl)-2-methoxyphenoxy]-1,3-propanediol (PPD) was previously isolated and identified as the bioactive ingredient in SWH. The present study aimed to characterize the bone protective effects as well as its mechanism of actions in osteoblasts. Materials and methods Bone protective actions of PPD on different cells were determined by proliferation assay, alkaline phosphatase (ALP) activity assay, calcium deposition as well as real-time reverse transcriptase-polymerase chain reaction (RT-PCR). In addition, estrogen receptor (ER) antagonist ICI182,780 and mitogen-activated protein kinase kinase (MEK) inhibitor U0126 blocking assays, competitive ER radioligand binding assay, ERE-dependent luciferase reporter assay and immunoblotting were used to determine if PPD activated ER and if the effects of PPD on osteoblastic functions were ER dependent. Results PPD exerted anabolic effects in osteoblasts and its effects were abolished by co-incubation with ICI182,780 or U0126. PPD induced mRNA expressions of Runx2, ALP, osteocalcin, and increased the ratio of osteoprotegerin/receptor activator of nuclear factor κB (OPG/RANKL). PPD failed to bind to either ERα or ERβ and did not activate ERE-luciferase activity via ER. PPD induced the phosphorylation of extracellular regulated kinases (ERK) and its effect was completely abolished by U0126. It also induced the phosphorylation of ERα at serine 118. Conclusion These data show that PPD is a bioactive compound in SWH that exerts oestrogen-like actions in osteoblast-like cells via ligand-independent, estrogen response element (ERE)-independent and mitogen-activated protein (MAP) Kinase-mediated rapid nongenomic ER signaling pathway.
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PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2014
·
IF 3.84
Zi-Ming Zhou,Yong Yu,Ming-Zhen Zhang,Jun Chen,Qiong-Qiong Ren,Ji-Tao Song,Bo Liu,Zhi-Ya Ma,Yuan-Di Zhao
It is important to design new ways with high specificity and sensitivity to detect lead (II). Here, ‘8–17’ DNAzyme was used as a Pb 2+ -dependent probe with high sensibility and selectivity based on chemiluminescence (CL). When Pb 2+ was present, the substrate strand was cleaved and the active hemin/G-quadruplex DNAzyme structure was formed in the presence of another sequence which contained two parts, one could be complementary with part of the substrate strand and the other was a G rich subunit. The active hemin/G-quadruplex DNAzyme structure could catalyze luminol oxidation and quantitative analysis of Pb 2+ was carried out according to the CL of luminol. Results showed that CL intensity of luminol at 452 nm had a linear relation with the concentration of Pb 2+ in the range from 5 nM to 1 μM, and the limit of detection was 0.79 nM ( S / N = 3). This method was also used to detect the contents of Pb 2+ in lake water and tobacco and the results (62.4 ± 4.0 nM and 15.2 ± 2.2 nM, respectively) were extremely closed to those of inductively coupled plasma-mass spectrometry (ICP-MS) (57.0 ± 1.4 nM and 14.5 ± 0.91 nM, respectively).
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高影响因子
MICROCHIMICA ACTA
·
2014
·Vol. 181
·期 13
·1573-1580
·
IF 3.719
Wang Meilan,Wu Huan,Chi Yuwu,Chen Guonan
Heating and drying of the mixture of glutathione-etched gold nanoparticles (Au-SG) and β-cyclodextrin (β-CD) results in the formation of β-CD-capped and glutathionate-protected Au 13 nanoclusters (Au 13 (SG) 8 @β-CD). Their particle size, composition, and number of gold atoms and the capping molecules were characterized by scanning electron microscopy, fluorescence, UV–vis absorption, FT-IR spectroscopy and mass spectrometry. The fluorescence of these nanoclusters is specifically enhanced by the addition of Ag(I) ions to the aqueous solution. This effect was exploited to develop a selective and sensitive method for the fluorometric determination of Ag(I) in water in the concentration range between 0.5 nM and 0.1 μM, with a detection limit at 0.3 nM (at a signal-to-noise ratio of 3).
β-CD-capped Au 13 nanoclusters has been synthesized by heating and drying the mixture of glutathione-etched gold nanoparticles and β-CD. A simple, sensitive and selective FL sensing method for Ag + in environmental water has developed using the Au nanoclusters.
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高影响因子
JOURNAL OF NANOPARTICLE RESEARCH
·
2017
·Vol. 19
·期 8
·1-11
·
IF 2.02
Cheong Ling-Zhi,Wei Yayu,Wang Hongbin,Wang Zhiying,Su Xiurong,Shen Cai
Zeolitic imidazolate frameworks (ZIF) represent one of the metal organic frameworks (MOF) with high potential for enzyme immobilization due to their exceptional chemical and thermal stability, negligible cytotoxicity, and easy synthesis under mild biocompatible conditions. Amine-functionalized ZIF-8 (An-ZIF-8) are capable of forming multipoint attachment via hydrogen bonding with lipase which will immobilize and further enhance stabilization of lipase. In addition, increased hydrophilicity of An-ZIF-8 will increase partitioning of An-ZIF-8 immobilized lipase at the aqueous/organic interface which enable lipase to expose its active site and retain its catalytic activity at its highest. Present study reports the use of ZIF-8 and An-ZIF-8 nanoparticles as carrier for Burkholderia cepacia lipase (BCL), compares the ester hydrolysis and transesterification activities of immobilized lipase with those of free lipase, and evaluates the reusability and recovery rate of the immobilized lipase. An-ZIF-8 nanoparticles (average 130.42 ± 0.55 nm) were facilely synthesized via mixing ZIF-8 nanoparticles with ammonia hydroxide solution. Despite having similar characteristics of high crystallinity and forming cuboid-like particles, An-ZIF-8 demonstrated significantly ( P < 0.05) lower Brunauer-Emmett-Teller (BET) surface area and higher thermal stability than ZIF-8. BCL were successfully immobilized on ZIF-8 (BCL@ZIF-8) and An-ZIF-8 (BCL@An-ZIF-8) nanoparticles with an average lipase loading rate of ~ 8 mg/g MOF. The immobilized BCL demonstrated no significant differences in terms of esters hydrolysis and transesterification activities with those of free BCL. BCL@An-ZIF-8 demonstrated superior catalytic stability in comparison to BCL@ZIF-8 with retainment of more than 80% of its initial hydrolysis and transesterification activity for at least 10 repeated runs. In addition, more than 80% of the BCL@An-ZIF-8 can be easily recovered during each cycle of the reusability test through simple centrifugation.
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高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2016
·Vol. 163
·期 6
·H459
·
IF 3.014
Min Jiang,Xueping Cao,Ping Liu,Tongping Zhang,Jianming Zhang
As novel N-doped carbon precursors, zeolitic imidazolate framework-8@polyvinyl pyrrolidone (ZIF-8@PVP) composites were designed and synthesized. Direct carbonization of ZIF-8@PVP composites at a high temperature produced the nitrogen-doped porous carbon materials (named as CP1000). And the electrocatalytic abilities of the corresponding carbonized products toward oxygen reduction reaction in alkaline solution were investigated. In comparison with the carbonized product of pure ZIF-8 (named as C1000), CP1000 possesses the higher specific surface area and total pore volume. By adjusting the initial dosage of PVP, three kinds of CP1000 with different size and N content were prepared. It was found that the high specific surface area and favorable quaternary-N species in CP1000 sample played an active role in catalyzing oxygen reduction reaction (ORR).
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高影响因子
JOURNAL OF MEMBRANE SCIENCE
·
2017
·
IF 6.035
Xuehua Ruan,Xinfang Zhang,Xuhang Liao,Xiaobin Jiang,Yan Dai,Xiaoming Yan,Gaohong He
Zeolitic imidazolate framework-8 (ZIF-8) with regular pore size (~ 0.34 nm) is widely attempted for gas separation membranes based on size sieving. However, the prospect is subjected to fabricating the continuous ZIF-8 membranes with high mechanical stability and uniformity. In response, an adhesive layer of Zn(II)-doped polydopamine (Zn-PDA) is pre-coated on the stainless steel nets in this work to improve ZIF-8 nucleation and growth. Zn-PDA layer shows high tolerance to ultrasonic agitation and heated methanol (system for ZIF-8 synthesis), little dissolution within 24 h, which supplies a high stable surface for ZIF-8 growth. Furthermore, the Zn(II) doped in PDA layer is opportunely serving as the even-distributed ZIF-8 nucleation starting sites, verified with the EDX and FE-SEM images for the aggregated Zn(II) clusters and the nascent ZIF-8 crystals. Therefore, an indented and hinged boundary is constructed between ZIF-8 and substrate to enhance the mechanical stability. The FE-SEM images after ultrasonic agitation show that the continuous ZIF-8 membranes prepared on Zn-PDA layers can tolerate the deformation to a certain extent. Finally, the prepared ZIF-8 membranes behave excellently with α H2/CO2 = 9.9, α H2/CO = 17.2, α H2/CH4 = 26.0, and permeation rate J H2 = 3980 GPU. This work supplied a useful approach to enhance mechanical stability and uniformity of defect-free ZIF-8 membranes.
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高影响因子
危险品化学品经营许可证（带存储）