TALANTA
·
2019
·
IF 4.916
Wenfang Deng,Chang Cheng,Hui Yang,Hui Wang,Yueming Tan,Qingji Xie,Ming Ma,Shouzhuo Yao
We report here a sensitive method for immunoassay of Staphylococcus aureus ( S. aureus ) based on colorimetric and fluorescent responses of 4-chloro-7-nitrobenzo-2-oxa-1,3-diazole (NBD-Cl) to l -cysteine (Cys). S. aureus cells were separated from samples by immunomagnetic nanoparticles and labeled with Cys-encapsulated liposome ( [email protected] ) immuno-nanocapsules. After mangnetic separation, the [email protected] immuno-nanocapsules linked to bacterial cells were destructed by Tween-20, and then the released Cys molecules reacted with NBD-Cl to generate colorimetric and fluorescent signals. Due to the amplification effect of liposome nanocapsules , the high capture efficiency of immunomagnetic nanoparticles, and the high responses of NBD-Cl to Cys, the detection limits for colorimetric and fluorescent detection of S. aureus were as low as 10 and 1 CFU mL −1 , respectively. The proposed method was successfully used to detect S. aureus in milk samples. This work has provided a novel NBD-Cl based colorimetric and fluorescent platform for immunoassay.
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高影响因子
RSC Advances
·
2015
·Vol. 5
·期 91
·74977-74985
·
IF 3.84
Xin Xiao,Shunheng Tu,Chunxia Zheng,Huan Zhong,Xiaoxi Zuo,Junmin Nan
Large-scale synthesis of nanosized β-Bi2O3 is a significant challenge due to its metastable state. A facile L-asparagine-assisted reflux–calcination route was successfully developed for the large-scale preparation of β-Bi2O3 micro/nanostructures under mild conditions (low temperature, atmospheric pressure, and wide temperature windows). The composition, phase structure, morphology, surface area, and photoabsorption properties of as-synthesized β-Bi2O3 and its precursor were systematically characterized. The phase transformation conditions and possible formation mechanism of flower-like β-Bi2O3 were discussed. It is found that with a simple reflux process under atmospheric pressure at 100 °C, uniform monodisperse bismuth–asparagine complex microspheres with average diameters of ∼500 nm were produced and flower-like β-Bi2O3 micro/nanostructures were then conveniently obtained after precursor calcination at temperatures ranging from 340 °C to 420 °C. A surface CO32− coordination effect introduced from L-asparagine explained the formation of stabilized β-Bi2O3 at low temperatures (up to 420 °C). The as-synthesized β-Bi2O3 shows excellent photocatalytic activity toward the degradation of 4-phenylphenol under visible-light irradiation, which is 3.7 and 21.4 times faster than the removal rates of β-Bi2O3 nanospheres and a commercial β-Bi2O3, respectively, and allows for the elimination of 93.2% total organic carbon after 60 min of irradiation. In addition, the photogenerated reactive species were identified by radical scavenger experiments and electron paramagnetic resonance spectroscopy, and a possible visible-light-induced photocatalytic mechanism was then proposed.
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Journal of Materials Chemistry B
·
2013
·Vol. 1
·期 17
·2268-2274
·
IF 0
Lijian Chen,Bing Sun,Xindong Wang,Fengmin Qiao,Shiyun Ai
In this report, a novel approach for exfoliation of Co–Al layered double hydroxides (LDHs) in aqueous solution of L-asparagine was proposed. L-Asparagine is a water-soluble amino acid whose carbonyl groups would have a strong interaction with the LDH host layers and the amino groups might weaken the interlayer interactions. This simple method did not need reflux at high temperature, overcame the drawback of using organic solvents, and even resulted in a stably stored colloidal suspension of 2D nanosheets. Besides, the peroxidase-like activity of the exfoliated Co–Al LDH (Co–Al ELDH) was enhanced compared with unexfoliated LDH. Co–Al ELDH could rapidly catalyze oxidation of the peroxidase substrate 3,3′,5,5′-tetramethylbenzidine (TMB) in the presence of H2O2, producing a blue color reaction. On this basis, simple, rapid and selective colorimetric methods for H2O2 and glucose detection were developed. The presented means was used for glucose detection in fruit juices and fine results were obtained.
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EUROPEAN POLYMER JOURNAL
·
2015
·
IF 3.005
Limiao Lin,Yonghang Xu,Shuanjin Wang,Min Xiao,Yuezhong Meng
An economic and biocompatible Schiff base tri-zinc catalyst was used to synthesize homo/copolymers of l -lactide (LA) and ε-caprolactone (CL) in bulk at first time. Both 1 H and 13 C NMR analyses show that LA is more active than CL, resulting in a poly(LA- grad -CL) copolymer with gradient sequence structure. A series of copolymers containing varying LA/CL ratios were readily synthesized. The chemical structure of poly(LA- grad -CL) was fully investigated using NMR and GPC technologies. TGA, DSC, DMA and nanoindentation instruments were employed to evaluate thermal and mechanical properties of these polymers. The results indicate that polymer composition and chain structure have a great impact on the crystallization behavior and crystallinity, as well as the thermal and mechanical properties of the copolymers. Therefore, the performance of the copolymer can be then tailored by simply adjusting the ratios of LA to CL.
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INTERNATIONAL JOURNAL OF FOOD SCIENCES AND NUTRITION
·
2015
·
IF 1.206
Qingyu Wang,Zhongyao Du,Hao Zhang,Liang Zhao,Jing Sun,Xiaonan Zheng,Fazheng Ren
This study aimed to evaluate the beneficial effects of polyphenol extract of adlay (Coix lacryma-jobi L. var. ma-yuen Stapf.) (PEA) on gut microbiota in rats fed a high-cholesterol diet (HCD). Rats were fed HCD containing 1% cholesterol (w/w), with or without a daily intragastric supplement of 200 mg/kg body weight PEA. Results showed that PEA significantly ameliorated increases in serum cholesterol and low-density lipoprotein cholesterol values and significantly restored high-density lipoprotein cholesterol values. The HCD-induced imbalance of gut microflora was modulated by the consumption of PEA. Most bacterial strains influenced by PEA are related to host lipid metabolism. The abundances of one Erysipelotrichales strains and two Clostridia strains were lower in the PEA group than in the control. Phenolic compounds in PEA were identified by HPLC. The findings indicate that PEA may be a useful dietary supplement in the treatment of elevated cholesterol levels and the imbalanced gut microbial ecology.
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DALTON TRANSACTIONS
·
2014
·Vol. 43
·期 37
·14123-14131
·
IF 4.097
Lei Chen,Bing Yan
Both zeolite A/L and SBA-15 have been used to assemble novel photofunctional multi-component lanthanide hybrid materials. Microporous zeolites A/L are first functionalized by embedding lanthanide or zinc complexes (TTA = thenoyltrifluoroacetone, TAA = trifluoroacetone, bipy = 2,2′-bipyridyl) into the pores of zeolite A/L, and then the surface of functionalized zeolite A/L is modified via covalent linkers from aromatic carboxylic acids (para-aminobenzoic acid ABA and para-hydroxyl benzoic acid HBA) grafted by 3-(triethoxysilyl)-propyl isocyanate (TEPIC). On the other hand, SBA-15 is modified by grafting covalent linker phen-Si from the modification of 1,10-phenanthroline (phen) with TEPIC. Further, another lanthanide ion is used to link both functionalized zeolites, A/L and SBA-15, through the coordination with the two covalent linkers, ABS-Si (HBA-Si) and phen-Si, respectively. Subsequently, the obtained multicomponent microporous–mesoporous hybrid materials are assembled and characterized using XRD, FT-IR, UV-vis DRS, SEM, TEM and luminescent approaches (spectra, lifetimes and quantum efficiencies). These hybrids with both microporous zeolite and SBA-15 mesoporous host possess favourable luminescent performance and some hybrid systems present the high quantum efficiencies of 90%. Besides, the luminescent color can be tuned by adjusting the composition of these hybrids, among which four hybrids (S-phen-Eu-HBA-[ZA-Tb-bipy], S-phen-Eu-HBA-[ZA-Zn-bipy], S-phen-Eu-ABA-[ZA-Tb-TAA], S-phen-Eu-ABA-[ZL-Tb-bipy]) can be integrated to white light emission.
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COLLOIDS AND SURFACES B-BIOINTERFACES
·
2013
·
IF 3.554
Fang Du,Haijing Meng,Ke Xu,Yanyun Xu,Ping Luo,Yu Luo,Wei Lu,Jin Huang,Shiyuan Liu,Jiahui Yu
This research is aimed to develop a nanoparticle delivery system based on β-cyclodextrin-grafted diblock copolymer and camptothecin (CPT) inclusion complexes with the purpose of enhancing the stability of CPT in aqueous media. Firstly, mPEG-PBLG diblock copolymer was synthesized by the ring-opening polymerization of γ-benzyl- l -glutamate-N-carboxyanhydride (BLG-NCA) initiated with amine terminated poly (ethylene glycol) monomethyl ether (mPEG-NH 2 ). After removal of benzyl groups, mono-6-amine-β-cyclodextrin (EDA-β-CD) units were coupled to the carboxyl groups of the copolymer as side groups to produce the host macromolecule mPEG-PLG(CD). The highly hydrophobic anticancer drug CPT was employed as the guest component which could be included into the host macromolecule to form supramolecular inclusion-complex mPEG-PLG(CPT@CD). Interestingly, the supramolecular complexes were able to form spherical nanoparticles with an average size of 98 nm in aqueous media confirmed by dynamic light scattering (DLS) and transmission electron microscopy (TEM), suggesting their passive targeting potential to tumor tissue. Due to the protection effect from a dual lock system (the environment of nanoparticles and the exterior surface of β-CD), the active lactone ring of CPT showed remarkably enhanced stability against hydrolysis under physiological condition. The release profile of the mPEG-PLG(CPT@CD) nanoparticles in PBS buffer was found to be gradual and sustaining. It was worthy to note that the release could be accelerated by addition of adamantane carboxylate (ADC) as competitive guest compound, demonstrating the chemically stimulated release behavior of the nanoparticles. Compared with free CPT, the mPEG-PLG(CPT@CD) nanoparticles displayed essentially decreased cytotoxicity against MCF-7 cell line in 24 h because of a sustained release profile of CPT from the nanoparticles, moreover, the carrier mPEG-PLG(CD) itself showed almost no cytotoxicity, indicating its great potential as tumor tissue targeted drug delivery system.
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MICROCHIMICA ACTA
·
2015
·Vol. 182
·期 13
·2277-2283
·
IF 3.741
Wang Yong,Qu Jianhang,Li Shufang,Dong Ying,Qu Jianying
We describe an electrochemical sensor for simultaneous determination of hydroquinone (HQ) and catechol (CC). A glassy carbon electrode (GCE) was modified with gold nanoparticles, L-cysteine, and ZnS/NiS@ZnS quantum dots using a layer-by-layer technique. The materials were characterized by X-ray diffractometry, field emission scanning electron microscopy, and electrochemical impedance and Fourier transform infrared spectroscopy. Cyclic voltammetry and differential pulse voltammetry revealed this modified GCE to represent a highly sensitive sensor for the simultaneous determination of HQ and CC. The anodic peak current for HQ at a working voltage of 80 mV (vs. Ag/AgCl) is related to its concentration in the 0.1 to 300 μM range (even in the presence of 0.1 mM of CC). The anodic peak current for CC at a working voltage of 184 mV is related to its concentration in the 0.5 to 400 μM range (even in the presence of 0.1 mM of HQ). The detection limits (at an S/N ratio of 3) are 24 and 71 nM for HQ and CC, respectively. The modified GCE was successfully applied to the determination of HQ and CC in aqueous solutions and gave satisfactory results.
A glassy carbon electrode was modified with gold nanoparticles, ZnS/NiS@ZnS quantum dots and L-cysteine and used for simultaneous determination of hydroquinone and catechol.
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ENVIRONMENTAL POLLUTION
·
2015
·
IF 4.143
Hai-Ming Zhao,Huan Du,Lei Xiang,Yi-Liang Chen,Lei-An Lu,Yan-Wen Li,Hui Li,Quan-Ying Cai,Ce-Hui Mo
Phthalate ester (PAE) accumulation in crops poses great risks to human health and has aroused great concern. Here, we investigated variations in di- n -butylphthalate (DBP) and di-(2-ethylhexyl) phthalate (DEHP) accumulation by various Chinese flowering cabbage cultivars and revealed their variation mechanism. There were significant differences ( p < 0.05) in shoot PAE concentrations of 28 cultivars. Moreover, significant positive correlations between DBP and DEHP concentrations in shoots of all cultivars indicated that they could be taken up simultaneously by various cultivars. Due to the lower translocation factor of low-PAE accumulator, its shoot PAEs concentrations were much lower than root compared to high-PAE accumulator. Further, subcellular distribution showed that PAE concentrations of root cell walls and organelles were much higher than those of shoots in low-PAE accumulator. Therefore, lower translocation from root to shoot and more PAEs accumulating in cell walls and organelles of root might act as main formation mechanism of low-PAE accumulator.
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高影响因子
Journal of Materials Chemistry B
·
2016
·Vol. 4
·期 7
·1284-1295
·
IF 4.872
Min Tang,Haiqing Dong,Yongyong Li,Tianbin Ren
Dendrimer catiomers like dendrigraft poly-L-lysine (DGL) have been very popular vectors for gene delivery recently; however, they generally suffer from serious cytotoxicity for high density of positive charge. PEGylated DGL engineered using the PEG cleavable mechanism (DGL(R)-SS-mPEG) was first developed as a non-viral gene vector for cancer intervention. Cleavable PEGylation of the DGL catiomer in tumor relevant glutathione (GSH) conditions enables us to dramatically decrease the cytotoxicity as well as to promote the intracellular release and expression of the genetic payload. Like DGL, DGL(R)-SS-mPEG is capable of efficiently complexing with plasmid DNA (pDNA) to afford homogeneous compact nano-complexes. Those gene carrying nanostructures could be stably dispersed in the regular serum medium without GSH, but with fast PEG dis-assembly if subject to 10 mM GSH. Compared with the non-cleavable counterpart, PEG-cleavable dendrigraft poly-L-lysine exhibited significantly higher enhanced green fluorescence protein (EGFP) expression against 293T cells. By using small interfering RNA (siRNA-VEGF) as the therapeutic gene payload, the complex nanoparticles demonstrated the pronounced inhibition effect on cell growth in vitro and tumor growth in vivo. The promising results revealed a universal strategy to balance disadvantages and advantages of dendrimer catiomers for future non-viral gene delivery vector.
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MACROMOLECULAR CHEMISTRY AND PHYSICS
·
2017
·Vol. 218
·期 16
·1700178
·
IF 2.5
Xuefei Leng,Yingying Ren,Zhiyong Wei,Yufei Bian,Yang Li
A series of highly branched star-comb poly(ε-caprolactone)- block -poly( l -lactide) (scPCL- b -PLLA) are successfully achieved using star-shaped hydroxylated polybutadiene as the macroinitiator by a simple “grafting from” strategy. The ration of each segment can be controlled by the feed ratio of comonomers. These star-comb double crystalline copolymers are well-defined and expected to illustrate the influences of the polymer chain topology by comparing with their counterparts in linear-shaped, star-shaped, and linear-comb shape. The crystallization behaviors of PCL- b -PLLA copolymers with different architectures are investigated systematically by means of wide-angle X-ray diffraction, differential scanning calorimetry, and polarized optical microscopy analysis. It is shown that the comb branched architectures promote the crystallization behavior of each constituent significantly. Both crystallinity and melting temperature greatly raise from linear to comb-shaped copolymers. Compared to linear-comb topology, the star-comb shape presents some steric hindrance of the graft points, which decrease the crystallinity of scPCL- b -PLLA. Effects of copolymer composition and chain topology on the crystallization are studied and discussed.
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JOURNAL OF SEPARATION SCIENCE
·
2016
·Vol. 39
·期 10
·1853-1862
·
IF 2.741
Xianrui Liang,Qiao Xu
A validated method based on ultra-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was established to separate and identify phenolic compounds in Bidens pilosa L. Mass spectrometry experiments were performed both in positive and negative ion modes. A total of 35 compounds were detected, and 26 phenolic compounds were unequivocally identified or tentatively assigned based on retention time, maximum UV absorption, molecular formula, and fragments. The ultra high performance liquid chromatography method was validated and showed good linearity ( R 2 ≧ 0.9996) over the test range. The limits of detection and quantification were above 0.072 and 0.162 μg/mL, respectively. The relative standard deviations of intraday and interday precision were below 0.3 and 1.6%, respectively.
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危险品化学品经营许可证（带存储）