MICROCHIMICA ACTA
·
2018
·Vol. 185
·期 10
·1-10
·
IF 5.705
Huang Yan-Qin,Yang Li-Na,Wang Yong-Sheng,Xue Jin-Hua,Chen Si-Han
The authors report on a one-pot approach for synthesizing highly fluorescent protamine-stabilized gold nanoclusters. These are shown to be a viable nanoprobe for selective and sensitive fluorometric determination of lead(II) via quenching of fluorescence via Pb(II)-Au(I) interaction. Under optimized conditions, fluorescence measured at excitation/emission peaks of 300/599 nm drops in the 80 nM–15 μM lead(II) concentration range. The detection limit is 24 nM, and relative standard deviations (for n = 11) at concentrations of 0.10, 4.0 and 15 μM are 1.6, 2.5 and 1.9%, respectively. The relative recoveries of added lead(II) in the water samples ranged from 97.9 ± 2.29% to 101.2 ± 1.83%.
Lead(II) ions are found to be able to selectively and sensitively quench the fluorescence of the protamine-gold nanoclusters (PRT-AuNCs). Thereby, an inexpensive, selective and sensitive lead(II) assay was established.
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CHEMISTRY-A EUROPEAN JOURNAL
·
2017
·Vol. 24
·期 8
·1898-1904
·
IF 5.317
Shaofan Fang,Guangshe Li,Yantong Lu,Liping Li
Graphical Lifting the curse : We reported on a novel route by using solid metal halides as halide sources that achieve an anion exchange with CsPbX 3 without any pretreatment. Introducing small amounts of oleic acid or oleylamine speed up the exchange reaction rate, although showing different promotion mechanisms (see figure). Cesium lead halide perovskite (CsPbX 3 ) nanocrystals (NCs) exhibit an excellent photoelectric performance, which is directly governed by fine-tuning of the composition and preparation of materials with a special phase structure and morphology. However, it is still facing challenges to achieve highly stable and luminescent CsPbX 3 NCs at room temperature. Herein, we report on a novel exchange reaction, in which metal halides MX 2 (M=Zn, Mg, Cu, or Ca; X=Cl, Br, or I) solids act as anion source to directly prepare CsPbX 3 NCs at room temperature without any pretreatment. Introducing small amount of oleic acid or oleylamine speed up the exchange reaction through different promotion mechanisms. Oleic acid coordinates to the surface of the NCs, which increases the reaction activity, and oleylamine greatly enhances the dissolution of ZnCl 2 . XRD and TEM tests demonstrate that the cubic phase structure and the morphology of the parent CsPbX 3 were well preserved. Moreover, the band-gap energies and photoluminescence (PL) spectra were readily tunable over the entire visible spectral region of λ =406–685 nm. Our findings could open up the possibilities of using metal halide solids as new anion sources to prepare high-quality CsPbX 3 NCs at room temperature.
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WORLD JOURNAL OF MICROBIOLOGY & BIOTECHNOLOGY
·
2024
·Vol. 41
·期 1
·1-12
·
IF 4
Li Yang-Nan,Zhu Chen-Yuan,Xu Chen-Lu,Yu Shen,Huan Tong,Zhang Ye-Wang
A heparinase III ( Ns Hep-III) from Niabella sp . was identified, cloned, and expressed as soluble form in E. coli BL21 (DE3). With heparin as substrate, the maximum activity of Ns Hep-III of 90.0 U·mg − 1 was achieved at pH 7.1 Tris-HCl (containing 15 mM Mg 2+ ) and 30 o C. The half-life of Ns Hep-III was determined to be 5 h at 30 o C. The interactions between Ns Hep-III and substrates were studied by molecular docking. The combination of Ns Hep-III and a heparinase I from Bacteroides eggthii ( Be Hep-I) was employed to cleave heparin. Analysis of the enzymatic products of Ns Hep-III by SAX-HPLC showed seven different modified disaccharides, indicating that Ns Hep-III has a wide range of substrate specificity. The results of GPC analysis demonstrated that the average molecular weight of the product of heparin cleavage by the combination of Ns Hep-III/ Be Hep-I was reduced to 3969 Da, which accounted for 90% of all the components, and complied with the requirements of the European Pharmacopoeia. Ns Hep-III has notable activity and efficiency in cleaving heparin, which is potentially useful for the industrial production of low molecular weight heparin.
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SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
·
IF 9
Shuliang Chen,Yuxin Yang,Futing Zi,Xianzhi Hu,Xinrong Li
The high capacity and selective recovery of gold(I) thiosulfate complex are the greatest obstacles hindering the rapid development of thiosulfate gold leaching technology. In this study, a batch of adsorbents for gold ion recovery from thiosulfate solutions were synthesized by functionalizing polystyrene cross-linked microspheres (PCMS) via nucleophilic substitution reactions using organic phosphines(III) with different carbon number as functional monomers. Increasing the pH of the adsorption solution or reducing the carbon number of the functional monomer in the adsorbent were found to enhance the gold ion adsorption performance of the adsorbent. The adsorbent (PCMS-TMP) obtained from the reaction of trimethylphosphine and PCMS exhibited the best gold adsorption performance, achieving a gold loading capacity of 136.42 mg/g. It also demonstrated selective recovery of low-concentration gold ions (6.175 mg/L), with a recovery rate as high as 98 %. The adsorption process of gold ions on PCMS-TMP was accurately described by the Langmuir isotherm and pseudo-second-order kinetic model. The gold adsorption process on PCMS-TMP primarily involved an anion exchange between Cl - and Au(S 2 O 3 ) 2 3- , which was also theoretically validated through density functional theory calculations. Clearly, PCMS-TMP is an adsorbent with significant capacity and selective recovery capabilities for Au(I) from thiosulfate solutions.
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ADVANCED FUNCTIONAL MATERIALS
·
2017
·Vol. 27
·期 31
·1702613
·
IF 12.124
Liyan Yang,Feilong Cai,Yu Yan,Jinghai Li,Dan Liu,Andrew J. Pearson,Tao Wang
The π-conjugated organic small molecule 4,4′-cyclohexylidenebis[ N , N -bis(4-methylphenyl) benzenamine] (TAPC) has been explored as an efficient hole transport material to replace poly(3,4-ethylenedio-xythiophene):poly(styrenesulfonate) (PEDOT:PSS) in the preparation of p-i-n type CH 3 NH 3 PbI 3 perovskite solar cells. Smooth, uniform, and hydrophobic TAPC hole transport layers can be facilely deposited through solution casting without the need for any dopants. The power conversion efficiency of perovskite solar cells shows very weak TAPC layer thickness dependence across the range from 5 to 90 nm. Thermal annealing enables improved hole conductivity and efficient charge transport through an increase in TAPC crystallinity. The perovskite photoactive layer cast onto thermally annealed TAPC displays large grains and low residual PbI 2 , leading to a high charge recombination resistance. After optimization, a stabilized power conversion efficiency of 18.80% is achieved with marginal hysteresis, much higher than the value of 12.90% achieved using PEDOT:PSS. The TAPC-based devices also demonstrate superior stability compared with the PEDOT:PSS-based devices when stored in ambient circumstances, with a relatively high humidity ranging from 50 to 85%.
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Journal of Food Measurement and Characterization
·
2016
·Vol. 11
·期 2
·548-555
·
IF 0.521
Xiaohong Zhang,Zhidong Zhao,Xiongwei Lou,Jian Li,Guohua Hui
A maltose, L-rhamnose sensor based on porous Cu foam and electrochemical techniques was investigated in this paper. Cu foam material was prepared and characterized by scanning electron microscopy (SEM). The electro-oxidation reaction process of sweeteners occurred on Cu foam electrode was evaluated by cyclic voltammetry (CV) scanning. At an applied potential of 0.5 V, the linear range for maltose is 0.18–3.47 mM with sensitivity of 1.0492 mA cm −2 mM −1 . The limit of detection (LOD) was 15.86 μM (S/N = 3). The linear range for maltose is 0.18–3.47 mM with sensitivity of 0.6881 mA cm −2 mM −1 . The LOD was 24.18 μM (S/N = 3). Compared with Cu sheet electrode, Cu foam electrode showed higher current response towards maltose and L-rhamnose, leading to enhanced electrocatalytic activity, higher sensitivity, and lower LOD. Sweetener qualitative discrimination was carried out by stochastic resonance (SR) signal-to-noise ratio (SNR) spectrum eigen peak located noise intensities.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-11
·
IF 4.259
Zhi Zijian,Chen Jianle,Li Shan,Wang Wenjun,Huang Rui,Liu Donghong,Ding Tian,Linhardt Robert John,Chen Shiguo,Ye Xingqian
Pectin, a natural polysaccharide found in the cell wall of most higher plant such as citrus, has drawn much attention due to its potential beneficial role in facilitating the treatment of many diseases like cancer, hyper cholesterol and diabetes. However, the broad application of pectin faces great limitations as the large molecular size of pectin severely prevents its bioavailability in vivo . In this study, we report an effective and highly convenient approach to degrade natural pectin into lower molecular pectin. By combining ultrasound with Fenton system (US-Fenton), we show that ultrasound synergistically enhances the efficiency of Fenton reaction to degrade pectin into 5.5 kDa within only 35 minutes. Importantly, RG-I domain, the most effective portion of natural pectin, was well preserved and highly enriched. In addition, the antioxidant activities of US-Fenton-treated pectin was significantly elevated. The mechanism of this novel observation was further investigated through the multiple structural analyses including HPLC, IR and NMR. Taken together, we present a novel and convenient approach to generate ultra-low molecular weight pectin with high efficiency and higher bioactivity. We expect our approach will have broader applications in improving the bioavailability and bioactivity of other polysaccharide-based natural compounds.
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JOURNAL OF COORDINATION CHEMISTRY
·
2017
·
IF 1.795
Bu-Lin Chen,Li Liu,Xin-Xin Zhong,Abdullah M. Asiri,Khalid A. Alamry,Fa-Bao Li,Nian-Yong Zhu,Wai-Yeung Wong,Hai-Mei Qin
Three-coordinate copper halide complexes with a bidentate phosphine ligand have received much attention. Here, a series of three-coordinate dinuclear copper halide complexes containing a diphenylamino monodentate phosphine ligand, [CuX(dpnp)]2 (dpnp = N-[2-(diphenylphosphino)-4,5-dimethylphenyl]-N-phenylaniline, X = I (1), Br (2) and Cl (3)), were synthesized, and their molecular structures and photophysical properties were investigated. The structural analysis reveals that two copper(I) centers are bridged by two halogen ligands to form a dinuclear structure with a four-membered Cu2X2 ring. Crystal structures of 1–3 contain 1-D supramolecular arrays constructed by intermolecular C–H⋯π interactions. These complexes exhibit blue emission in the solid state at room temperature and have peak emission wavelengths at 483–487 nm with microsecond lifetimes (τ = 13.9–38.1 μs) and low emission quantum yields (<0.01%). The emission of complex 1 mainly originates from intraligand (IL) transition, whereas the emissions of complexes 2 and 3 are from a combination of MLCT, XLCT and IL transitions. The three complexes displayed good thermal stability.
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PLoS One
·
2014
·Vol. 9
·期 10
·e108647
·
IF 3.534
Yankai Du,Meishan Pei,Youjun He,Faqi Yu,Wenjuan Guo,Luyan Wang
Fe 3 O 4 (Fe 3 O 4 -CS) coated with magnetic chitosan was prepared as an adsorbent for the removal of Orange I from aqueous solutions and characterized by FTIR, XRD, SEM, TEM and TGA measurements. The effects of pH, initial concentration and contact time on the adsorption of Orange I from aqueous solutions were investigated. The decoloration rate was higher than 94% in the initial concentration range of 50–150 mg L −1 at pH 2.0. The maximum adsorption amount was 183.2 mg g −1 and was obtained at an initial concentration of 400 mg L −1 at pH 2.0. The adsorption equilibrium was reached in 30 minutes, demonstrating that the obtained adsorbent has the potential for practical application. The equilibrium adsorption isotherm was analyzed by the Freundlich and Langmuir models, and the adsorption kinetics were analyzed by the pseudo-first-order and pseudo-second-order kinetic models. The higher linear correlation coefficients showed that the Langmuir model (R 2 = 0.9995) and pseudo-second-order model (R 2 = 0.9561) offered the better fits.
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SENSORS AND ACTUATORS B-CHEMICAL
·
2015
·
IF 4.097
Pengjuan Ni,Yujing Sun,Haichao Dai,Shu Jiang,Wangdong Lu,Yilin Wang,Zhen Li,Zhuang Li
A novel colorimetric method for the detection of acetylcholinesterase (AChE) and its inhibitor by taking utilization of Ag [I] ion–3,3′,5,5′-tetramethylbenzidine (TMB) detection system has been proposed. Ag [I] ion could oxidize TMB to induce a blue color and an absorption peak centered at 652 nm. In the presence of AChE, acetylthiocholine (ACh) was hydrolyzed to thiocholine. Ag [I] ion could interact with thiocholine and thiocholine can reduce the oxidized TMB (oxTMB) to TMB, both of which suppressed the oxidation capacity of Ag [I] ion, resulting in a blue color fading and a decrease of the absorbance at 652 nm. The developed assay is highly sensitive with a low detection limit of 4.3 μU/mL. Moreover, the method was also applied in AChE inhibitor sensing. The obtained assay is fairly simple, inexpensive and sensitive without the utilization of nanomaterials, which may be not only used for the sensing of other hydrolytic enzyme activities with properly selected substrates, but also used for the screening of potential inhibitor drugs.
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JOURNAL OF MOLECULAR MODELING
·
2015
·Vol. 21
·期 12
·1-10
·
IF 1.736
Xu Shengxian,Wang Jinglan,Zhao Feng,Xia Hongying,Wang Yibo
Two copper(I) complexes [Cu(Pyz-Phen) 2 ]PF 6 (1) and [Cu(POP)(Pyz-Phen)]PF 6 (2) (Pyz-Phen = pyrazino[2,3- f ] [1, 10]phenanthroline, POP = bis[2-diphenylphosphino]-phenyl]ether) have been synthesized and characterized. The photophysical properties of these complexes in solution have been studied. The electronic absorption spectrum of complexes 1 exhibit the lowest-lying MLCT absorption band at 459 nm and high-energy ligand-based transitions at 275 nm, while that of complex 2 exhibits the MLCT/LLCT band at 400 nm and ligand π-π* band at 262 nm. In addition, both 1 and 2 show similar phosphorescence 3 MLCT/ 3 LLCT emissions with maximum emission wavelengths of 569 and 572 nm, respectively. Density functional theory (DFT) and time-dependent density functional theory (TDDFT) were employed to rationalize the photophysical properties of the complexes studied. The theoretical data confirm the assignment of the experimental absorption spectra and the nature of the emitting states.
Photophysical properties of copper(I) complexes containing pyrazine-fused phenanthroline ligands
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SYNTHETIC METALS
·
2015
·
IF 2.252
Jie Zhao,Yu Xie,Dongsheng Hu,Dongsheng Guan,Junhong Chen,Jian Yu,Shuai He,Ying Lü,Huilong Liu,Shaokui Bao,Lei Wang
The graphene (GN)/phenylenediamine–benzaldehyde (PD–BD) Schiff base Ag(I) complexes were synthesized by the Schiff-base reaction. The morphology and phase structure of the samples were characterized by electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction techniques. Their conductive properties were measured by a four-probe conductivity tester at room temperature. And their magnetic properties were tested by a vibrating sample magnetometer. These results show that the PD–BD Schiff base Ag(I) complexes are chemically bonded onto the GN framework to form an intercalated structure. The conductivity, saturation magnetization, residual magnetization and coercive force of the final complex are found to be 5.07 S cm −1 , 2.93 emu g −1 , 0.69 emu g −1 and 104.68 Oe, respectively. Finally, a possible formation and magnetic mechanism of the composites has also been proposed.
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