摘要：
Luminescent and stable CdSe/ZnS core/shell quantum dots (QDs) capped with L-carnitine are firstly prepared for optical determination of mercury ions in ethanol. LC capped QDs have desirable dispersibility, uniformity and good fluorescence properties and were characterized by fluorescence spectroscopy, transmission electron microscopy and infrared spectra. The functionalized QDs turned out to exhibit excellent long-term stability. The modified QDs allowed a highly sensitive determination of mercury ions via analyte-induced changes in the photoluminescence of them. A detection limit of 1.8 × 10−7 M (36.1 µg · L−1) of mercury ions was obtained, while the interfering effect of other ions (including alkali metal ions, alkali earth metal ions, Ni2+, Zn2+, Fe2+, Ag+ and anions such as NO3
−, SO4
2−, CO3
2− and halogen ions) was negligible even at a very high concentration. The possible mechanism is discussed.
摘要：
A study described the synthesis of water-soluble and stable semiconductor CdSe/ZnS QDs (quantum dots) by using β-CD (cyclodextrin) and α-CD as surface-coating agents in a very simple sonochemical method. Their potential application as enantioselective fluorescent sensors for amino acids (AA) was investigated. The resulting water-soluble QD nanoparticles retain the optical properties of the original hydrophobic QDs. It was discovered that the CD-QDs allow the highly enantioselective fluorescent recognition of amino acids. Within a certain concentration range, one enantiomer of the chiral amino acid can enhance the fluorescence intensity of the CD-QDs, whereas the other enantiomer hardly affects the fluorescence. Such unusually high enantioselective responses thereby make these CD-QDs very attractive as fluorescent sensors in determining enantiometric compounds.
摘要：
In this paper, a simple method for immobilization of acetylcholinesterase (AChE) on cysteamine self assembled monolayers modified gold electrode coupled with CdTe quantum dots (QDs) was proposed and thus a sensitive, fast and stable amperometric biosensor for quantitative determination of carbaryl was developed. The fabrication procedure was characterized by cyclic voltammetry, electrochemical impedance spectroscopy and fluorescence spectrum. The nanoparticles of CdTe QDs led to an increased effective surface area for immobilization of enzyme and their electrocatalytic activity promoted electron transfer reactions and catalyzed the electro-oxidation of thiocholine, thus amplifying the detection sensitivity. Due to the notable decrease in voltammetric signal of the immobilized AChE, a simple method for determination of carbaryl was established. The inhibition of carbaryl was proportional to its concentration in two ranges, from 1 to 50 ng mL−1 and from 50 to 500 ng mL−1, with a detection limit of 0.6 ng mL−1. The constructed biosensor which processes prominent characteristics and performance, such as good precision and reproducibility, acceptable stability and accuracy, fast response and low detection limit, has potential application in the characterization of enzyme inhibitors and detection of toxic compounds against to enzyme.
作者机构：
[Zhang, Lizhi; Xiao, Lifen; Qiao, Hui] Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
通讯机构：
[Xiao, Lifen] C;Cent China Normal Univ, Coll Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
关键词：
mesoporous TiO2;phosphatization;anode;lithium ion batteries;INTERCALATION ELECTRODE MATERIAL;ANATASE-TYPE TIO2;ELECTROCHEMICAL PROPERTIES;NANOTUBES;INSERTION;NANOCOMPOSITE;TEMPERATURE;NANORODS
摘要：
We report phosphatization is a promising method to enhance the performance of mesoporous TiO2 anode for lithium ion batteries. The resulting phosphated mesoporous TiO2 possessed higher reversible capacity and better cycling stability than the pure mesoporous TiO2. When cycled at 30 mA/g between 3.0 and 1.0 V, the initial capacity of phosphate mesoporous TiO2 was 249 mA h/g, significantly higher than that of pure mesoporous TiO2 (204 mA h/g). After 40 cycles, the capacity retention ratio of phosphate mesoporous TiO2 reached 83.7%, while pure mesoporous TiO2 had merely a capacity retention ratio of 62.3%. We believe that this phosphatization process could be used to enhance the electrochemical performance of other metal oxides for lithium ion batteries. (C) 2008 Elsevier B.V. All rights reserved.
摘要：
A novel hybrid bifunctional sensing platform for simultaneous determination of NO and 02 has been developed, whereby hematite nanotubes are immobilized into the chitosan matrix onto a gold electrode (labeled as HeNTs-Chi/Au). The HeNTs distributed in porous-structured chitosan matrix not only offer abundant active sites for bifunctional sensing of NO and 02, but also facilitate oxidation of NO and reduction of 02 dramatically. Straight calibration curves are achieved in analyte concentration ranges of 5.0 x 10(-8) to 1.25 x 10(-6) mol L-1 for NO and 2.5 x 10(-7) to 6.0 x 10(-6) mol L-1 for O-2. Also, the detection limits are low of 8.0 x 10(-9) mol L-1 for NO and 5.0 x 10(-8) mol L-1 for O-2. Such an efficient bifunctional sensor for NO and O-2 offers great potential in quantitation of NO levels in biological and medical systems, since NO level is highly regulated by various reactive oxygen species. (C) 2008 Elsevier B.V. All rights reserved.
作者机构：
[Lee, Shuncheng; Ho, Wingkei; Huang, Yu] Hong Kong Polytech Univ, Res Ctr Environm Technol & Management, Dept Civil & Struct Engn, Hong Kong, Hong Kong, Peoples R China.;[Zhang, Lizhi; Huang, Yu] Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol, Minist Educ, Wuhan 430079, Peoples R China.;[Yu, Jimmy C.; Li, Guisheng] Chinese Univ Hong Kong, Dept Chem, Hong Kong, Hong Kong, Peoples R China.;[Yu, Jimmy C.; Li, Guisheng] Chinese Univ Hong Kong, Environm Sci Program, Hong Kong, Hong Kong, Peoples R China.
通讯机构：
[Lee, Shuncheng] H;Hong Kong Polytech Univ, Res Ctr Environm Technol & Management, Dept Civil & Struct Engn, Hong Kong, Hong Kong, Peoples R China.
期刊：
Journal of Physical Chemistry C,2008年112(3):747-753 ISSN：1932-7447
通讯作者：
Zhang, Lizhi
作者机构：
[Zhang, Lizhi; Zhang, Xi; Ai, Zhihui; Jia, Falong] Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol Minist Educ, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, Lizhi] C;Cent China Normal Univ, Coll Chem, Key Lab Pesticide & Chem Biol Minist Educ, Wuhan 430079, Peoples R China.
摘要：
A general one-pot solvothermal process was explored to prepare BiOX (X = Cl, Br, I) powders by employing ethylene glycol as the solvent. The as-prepared BiOX powders were characterized by X-ray powder diffraction, scanning electron microscopy, transmission electron microscopy, high-resolution transmission electron microscopy, UV−vis diffuse reflectance spectroscopy, and nitrogen sorption. The resulting BiOX samples were phase-pure and of hierarchical microspheres consisting of nanoplates. The band gaps of the as-prepared powders were estimated to about 3.22, 2.64, and 1.77 eV for BiOCl, BiOBr, and BiOI, respectively. On the basis of characterization results, we proposed a possible process for the growth of hierarchical BiOX nanoplate microspheres. Moreover, we evaluated their photocatalytic activities on the degradation of methyl orange and compared them with TiO2 (Degussa, P25) under UV−vis light irradiation and C-doped TiO2 under visible light (λ > 420 nm) irradiation, respectively. It was found that all the BiOX samples were photocatalytically active and BiOI exhibited excellent activity under both UV−vis and visible light irradiation. The resulting hierarchical BiOX nanoplate microspheres are very promising photocatalysts for degrading organic pollutants and other applications.
摘要：
The structures of two dinuclear Cu(II) complexes of dtpb were determined. They are shown to be capable of inducing DNA condensation into nanometer- and micrometer-scale particles under neutral conditions.
摘要：
This work reports on a novel chitosan-hematite nanotubes composite film on a gold foil by a simple one-step electrodeposition method. The hybrid chitosan-hematite nanotubes (Chi-HeNTs) film exhibits strong electrocatalytic reduction activity for H2O2. Interestingly, two electrocatalytic reduction peaks are observed at -0.24 and -0.56 V (vs SCE), respectively, one controlled by surface wave and the other controlled by diffusion process. The Chi-HeNTs/Au electrode shows a linear response to H2O2 concentration ranging from 1 x 10(-6) to 1.6 x 10(-5) mol L-1 with a detection limit of 5 x 10(-8) mol L-1 and a sensitivity as high as 1859 mu A mu M-1 cm(-2). (C) 2007 Elsevier B.V. All rights reserved.
