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Aptamer-based competitive electrochemical assay of small biomolecules

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science china chemistry 2011年第5期54卷 822-826页

作者： ZHANG YuYong,XIANG Yun,CHAI YaQin & YUAN Ruo Key laboratory on Luminescence and Real-Time Analysis,ministry of education school of chemistry and chemical engineering,Southwest university,Chongqing 400715,china Key laboratory on Luminescence and Real-Time Analysis Ministry of Education school of chemistry and chemical engineering Southwest University Chongqing China

A convenient aptamer-based competitive electrochemical biosensor for a small biomolecule,adenosine,was described. The sensing surface was fabricated by self-assembly of an aptamer/mercaptohexanol monolayer on a gold disk electrode. The principle of this aptasensor is based on the competition between an adenosine target molecule and a ferrocene-conjugated signaling DNA strand for the aptamer binding site on the sensing surface. Due to the competitive nature of this assay,the electrochemical responses of the surface captured ferrocene are inversely proportional to log[adenosine] in the range from 0.05 to 3.2 μM,with a detection limit of 25 nM. Moreover,the aptasensor also shows high selectivity for adenosine. The proposed aptasensor thus holds great potential for the detection of other small biomolecules.

关键词： aptamer adenosine biosensor competitive assay differential pulse voltammetry

A whisker-like carbon composite for the immobilization of laccase and its bioelectrochemistry

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science china chemistry 2010年第6期53卷 1332-1336页

作者： MA GuoXian1,2,ZHONG QingDong2 & LU TianHong3 1Department of chemical engineering,Shanghai Institute of Technology,Shanghai 200233,china 2school of Materials science and engineering,Shanghai university,Shanghai 200072,china 3Department of chemistry,nanjing Normal university,nanjing 210097,china Department of chemical engineering Shanghai Institute of Technology Shanghai China school of Materials science and engineering Shanghai University Shanghai China Department of chemistry Nanjing Normal University Nanjing China

A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were *** was confirmed by XPS that Lac was strongly adsorbed on the surface of the MCWC *** cyclic voltammetric results showed that the immobilized Lac underwent a direct quasi-reversible electrochemical *** value of the electron transfer rate constant ks was estimated to be 0.770 s-1,indicating a reasonably fast electron transfer between the immobilized Lac and the underlying *** surface concentration (I-) of Lac was estimated to be 2.730 × 10-12 mol/*** experimental results showed that the immobilized Lac displayed an appreciable electrocatalytic activity to the electrochemical reduction of *** properties could be attributed to the particular structure of loosely packed nanometer-scale carbon whiskers and the existence of a large amount of oxygen-containing *** immo- bilization method and the novel carrier (MCWC) may find new applications in fabricating the biocatalysts for biofuel cells.

关键词： laccase whisker-like carbon composite direct electrochemical reaction oxygen bioelectrochemistry

Annihilation of Radical Intermediate in Electrochemiluminescence of CdSe Quantum Dots Film/Peroxide System for Sensing Application

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Annihilation of Radical Intermediate in Electrochemiluminesc...

Controlled free radical polymerization of styrene initiated from the alkoxyamine-functionalized silicon surface

The Eleventh International and the First Sino-Japan Bilateral Symposium on Electroanalytical chemistry

作者： Hui JIAN Huangxian JU MOE Key laboratory of analytical chemistry for life science and school of chemistry and chemical engineering,nanjing university,nanjing 210093,china

Owing to the unique size-dependent optical and electronic properties,quantum dots(QDs)are of considerable current interests in bioassays and bioimagings[1].Although the electrochemiluminescence(ECL)from QDs has been well studied in organic solutions[2],few works focus on the possible sensing applications based on the ECL of *** previous work

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来源： cnki会议评论

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science china chemistry 2005年第5期48卷 449-458页

作者： CHEN Zhijun1, ZHOU Sikai1, LU Wenzhong1, FANG Shaoming1, JIANG Xiqun2 & YANG Changzheng2 1. College of Materials and chemical engineering, Zhengzhou university of Light Industry, Zhengzhou 450002, china 2. laboratory of Mesoscopic Material science and Department of Polymer science & engineering, College of chemistry & chemical engineering, nanjing university, nanjing 210093, china College of Materials and chemical engineering Zhengzhou University of Light Industry Zhengzhou China laboratory of Mesoscopic Material science and Department of Polymer science & engineering College of Chemistry & Chemical Engineering Nanjing University Nanjing China

We describe a new method of fabricating a brush-like polystyrene layer anchored on the surface of the silicon substrate, which involves three steps, namely (i) the attachment of 3-methacryloxypropyltrimethoxysilane onto the silicon surface; (ii) the reaction of vinyl moiety at another extremity of the anchored 3-methacryloxypropyltrimethoxysilane to 4-Hydroxyl-2, 2, 6, 6-tetramethyl-1-piperidinyloxy (HTEMPO?) catalyzed by azobisisobutyronitrile (AIBN); (iii) living free radical grafting polymerization of styrene in the presence of HTEMPO?. The controllable living free radical polymerization permits accurate control of both the molecular weight and the polydispersity. X-photoelectron spectroscopy measurement proved that the alkoxyamine initiator layer forms on the silicon surface. XPS and Ellipsometry measurements showed that the poly-styrene chains were covalently anchored onto the silicon surface. The thickness of the grafted polymer layer can be accurately manipulated by altering the polymerization time. The new method allows synthesizing random copolymer and block copolymers by the sequential growth of monomers from the substrate surface.

关键词： polymer brush, controlled living free radical polymerization, thickness, atomic force microscopy, 3-methacryloxypropyltrimethoxysilane.

Molecular dynamics simulations on the structures and properties of ε-CL-20-based PBXs ——Primary theoretical studies on HEDM formulation design

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science china chemistry 2007年第6期50卷 737-745页

作者： XU XiaoJuan1,2, XIAO JiJun1, HUANG Hui3, LI JinShan3 & XIAO HeMing1 1 Department of chemistry, nanjing university of science and Technology, nanjing 210094, china 2 Department of chemistry, Yancheng Teacher’s College, Yancheng 224002, china 3 Institute of chemical Materials, china Academy of engineering Physics, Mianyang 621900, china Department of chemistry Nanjing University of Science and Technology Nanjing China Department of chemistry Yancheng Teacher’s College Yancheng China Institute of chemical Materials China Academy of Engineering Physics Mianyang China

Five polymer bonded explosives(PBXs)with the base explosive epsilon-CL-20(hexanitrohexaazaisowurtzi-tane),the most important high energy density compound(HEDC),and five polymer binders(Estane 5703,GAP,HTPB,PEG,and F_(2314))were *** dynamics(MD)method was employed to investigate their binding energies(E_(bind))3 ≈ epsilon-CL-20/GAP 314).By pair correlation function g(r)analyses,hydrogen bonds and vdw are found to be the main interactions between the two *** elasticity and isotropy of PBXs based epsilon-CL-20 can be obviously improved more than pure epsilon-CL-20 *** is not by changing the molecular structures of epsilon-CL-20 for each binder to affect the *** safety and energetic properties of these PBXs are mainly influenced by the thermal capability(C_p^(deg))and density(p)of binders,respectively.

关键词： high energy density material (HEDM), hexanitrohexaazaisowurtzitane (CL-20), polymer bonded explosives (PBXs), molecular dynamics (MD), compatibility, safety properties, mechanical properties, energetic properties

Progress in the development of techniques based on light scattering for single nanoparticle detection

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science china chemistry 2011年第8期54卷 1244-1253页

作者： ZHU ShaoBin, WANG Shuo, YANG LingLing, HUANG TianXun & YAN XiaoMei Department of chemical Biology, College of chemistry and chemical engineering Key laboratory for chemical Biology of Fujian Province Key laboratory of analytical science, Xiamen university, Xiamen 361005, china Department of chemical Biology College of Chemistry and Chemical Engineering Key laboratory for chemical Biology of Fujian Province Key laboratory of analytical science Xiamen University Xiamen China

Nanoparticles have recendy attracted extensive attention in view of their great potential in biomedicine and bioanalytical applications. Single particle detection via light scattering offers a simple and efficient approach for the size, size distribution, and concentration analysis of nanoparticles. In particular, intrinsic heterogeneity or rare events masked by ensemble averaging can be revealed. However, the sixth power dependence of Rayleigh scattering on particle size makes it very challenging to detect individual nanoparficles of small sizes. This article is intended to provide an overview of recent progress in the development of techniques based on light scattering for the detection of single nanoparticles.

关键词： light scattering single particle detection nanoparticles confocal correlation spectroscopy flow cytometry

Propane Dehydrogenation over PtSnNa Catalyst Supported on La-ZSM-5 Zeolite

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china Petroleum Processing & Petrochemical Technology 2010年第3期12卷 18-24页

作者： Huang Li Zhou Yuming Zhang Yiwei Li Qingning Tian Xiaoming (school of chemistry and chemical engineering,Southeast university,nanjing 211189) school of chemistry and chemical engineering Southeast University Nanjing 211189 China

The La-ZSM-5 zeolite with different contents of La was synthesized by the hydrothermal method. The physico-chemical properties of the materials were studied. The results of FT-IR analyses indicated that La might be incorporated into the framework of ZSM-5 zeolite. The NH3-TPD analyses showed that the amount of weak acid sites of the zeolite decreased with a continuously increasing La content. Afterwards, the La-ZSM-5 zeolite was used as the support of PtSnNa catalyst for propane dehydrogenation. The test results revealed that the utilization of La- ZSM-5 zeolite could achieve a high propene conversion, and effectively inhibit the coke formation on the catalyst surface. When the content of La was 0.16%, the catalytic activity and stability of the catalyst got the best of its performance. Besides, the PtSnNa/La （0.16%）-ZSM-5 catalyst is more stable than the conventional PtSnNaLal ZSM-5 catalysts.

关键词： La-ZSM-5 propane dehydrogenation propene.

Structures and stability of isomers of[C,N,N,P]system

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science china chemistry 2005年第5期48卷 415-423页

作者： KAN Wei1,2, ZHONG Hua1, YU Haitao1, FU Honggang1,3 & SUN Jiazhong1,3 1. school of chemistry and Materials science, Heilongjiang university, Harbin 150080, china 2. school of chemistry and chemical engineering, Qiqihar university, Qiqihar 161006, china 3. State Key laboratory of Theoretical and Computational chemistry, Institute of Theoretical chemistry, Jilin university, Changchun 130023, china school of chemistry and Materials science Heilongjiang University Harbin China school of chemistry and chemical engineering Qiqihar University Qiqihar China Jilin university Changchun China

Nine isomers, twenty transition states, and some relative dissociation fragments of [C,N,N,P] system were located at the B3LYP/6-311G(d) and QCISD(t)/6-311+G(2df) (single-point) levels of theory, and the isomerization, structures, and stability of these obtained isomers were suggested. The results indicate that four nonlinear chainlike isomers NCNP, NCPN, CNPN, and CNNP with 2A′ electronic state are kinetically stable. Other isomers are kinetically unstable to-wards isomerization or dissociation because of the corresponding smaller reaction barriers. Furthermore, calculated vibrational frequencies, rotational constants, dipole moments, the first adiabatic ionization energies, and adiabatic electron affinities of the four isomers may provide some theoretical information that is helpful for identifying their existence in future laboratory and interstellar investigations. The results are also compared with [Si,N,N,P] system.

关键词： potential energy surface, [C,N,N,P] system, isomerization, kinetic stability.

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

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science china chemistry 2006年第5期49卷 445-453页

作者： YANG Weiben1,2,3,LI Aimin1,3,CAI Jianguo1,3,MENG Guanhua1,3 & ZHANG Quanxing1,3 1. State Key laboratory of Pollution Control and Resource Reuse,school of the Environment,nanjing university,nanjing 210093,china 2. nanjing College of chemical Technology,nanjing 210048,china 3. Jiangsu engineering & Technology Research Center for Organic Toxicant Control and Resource Reuse,nanjing 210038,china State Key laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing China nanjing College of chemical Technology Nanjing China Jiangsu engineering & Technology Research Center for Organic Toxicant Control and Resource Reuse Nanjing China

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 38# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.

关键词： acrylic ester resin, surfactant, adsorption, pore size distribution, isotherm.