Nanoscale-enhanced Ru(bpy)(3)(2+) electrochemiluminescence labels and related aptamer-based biosensing system

A unique multilabeling at a single-site protocol of the Ru(bpy)(3)(2+) electrochemiluminescence (ECL) system is proposed. Nanoparticles (NPs) were used as assembly substrates to enrich ECL co-reactants of Ru(bpy)(3)(2+) to construct nanoscale-enhanced ECL labels. Two different kinds of NP substrates [including semiconductor NPs (CdTe) and noble metal NPs (gold)] capped with 2-(dimethylamino)ethanethiol (DMAET) [a tertiary amine derivative which is believed to be one of the most efficient of co-reactants of the Ru(bpy)(3)(2+) system] were synthesized through a simple one-pot synthesis method in aqueous media.

Nanoelectrocatalyst based on high-density Au/Pt hybrid nanoparticles supported on a silica nanosphere

A high-efficiency nanoelectrocatalyst based on high-density Au/Pt hybrid nanoparticles supported on a silica nanosphere (Au-Pt/SiO2) has been prepared by a facile wet chemical method. Scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy are employed to characterize the obtained Au-Pt/SiO2. It was found that each hybrid nanosphere is composed of high-density small Au/Pt hybrid nanoparticles with rough surfaces. These small Au/Pt hybrid nanoparticles interconnect and form a porous nanostructure, which provides highly accessible activity sites, as required for high electrocatalytic activity. We suggest that the particular morphology of the AuPt/SiO2 may be the reason for the high catalytic activity. Thus, this hybrid nanomaterial may find a potential application in fuel cells.

Effects of ultrahigh pressure extraction conditions on yields and antioxidant activity of ginsenoside from ginseng

Ultrahigh pressure technique was employed to extract ginsenosides from roots of ginseng (Panax ginseng C.A. Meyer). The optimal conditions for ultrahigh pressure extraction (UPE) of total ginsenosides were quantified by UV-vis spectrophotometry with the ginsenoside Re as standard, the signal ginsenosides were quantified by HPLC and ELSD with ginsenosides Re, Rg(1), Rb-1, Rc and Rb-2 as standards. Orthogonal design was applied to evaluate the effects of four independent factors (extraction pressure, extraction temperature, extraction time and ethanol concentration) on the yield and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity of ginsenoside, which are based on microwave extraction (ME), ultrasound extraction (UE), soxhlet extraction (SE) and heat reflux extraction (HRE) method. The results showed that UPE method can produce ginsenoside with the highest yield and the best radical scavenging activity compared to other used ones. Scanning electron microscopic (SEM) images of the plant cells after ultrahigh pressure treatment was obtained to provide visual evidence of the disruption effect.

芸香苷铜(Ⅱ)络合物的电喷雾多级串联质谱分析

利用电喷雾离子阱质谱对黄酮苷类化合物———芸香苷与二价金属铜的络合物在软电离质谱条件下的络合行为进行了系统分析。所形成的 1∶1、2∶1、2∶2和 3∶2等不同化学计量比的芸香苷铜离子 (Ⅱ )络合产物 ,分别用 [R -H +Cu]+ ,[2R -H +Cu]+ ,[2R -3H +2Cu]+ 和 [3R -3H +2Cu]+ 表示。在多级串联质谱实验中 ,主要得到糖苷键断裂丢失寡糖链末端的鼠李糖基与苷元连接的葡萄糖基及整个寡糖链等中性碎片 ,同时也有寡糖链开环断裂和失水反应发生。

Phenolphthalein immobilized membrane for an optical pH sensor

A phenolphthalein immobilized cellulose membrane for an optical pH sensor was described. The phenolphthalein was first reacted with the formaldehyde to produce a series of prepolymers with many hydroxymethyl groups. In this paper, the prepolymers was abbreviated to phenolphthalein-formaldehyde (PPF). Then the PPF was covalently immobilized to the diacetylcellulose membrane via hydroxymethyl groups. Finally the membrane was hydrolyzed in the 0.1 M NaOH solution for 24 h to reduce the response time. Advantageous features of the pH-sensitive membrane include (a) a large dynamic range from pH 8.0 to 12.50, or even broader, (b) rapid response time (2-30 s), (c) easy of fabrication, and (d) a promising material for determination of high pH values. The immobilized PPF has a broader dynamic range from 8.0 to 12.50 than the free phenolphthalein from pH 8.0 to 11.0, and this was due to the newly produced methylenes in our investigation.

Polymeric pH indicators immobilized PVA membranes for optical sensors of high basicity based on a kinetic process

Two kinds of polymeric pH indicators PPF (phenolphthalein-formaldehyde product) and CPF (o-cresolphthalein-formaldehyde product) immobilized cross-linked poly(vinyl alcohol) membranes (PPF-PVA and CPF-PVA) for optical intermittent determination of high basicity ([OH-] = 1-8 M) based on a kinetic process were developed. In our previous work, we had demonstrated that PPF-PVA and CPF-PVA could perform the determination of high pH values from pH 10.0 to 14.0. Here the discoloring kinetic behaviors of PPF-PVA and CPF-PVA were compared with those of free phenolphthalein, o-cresolphthalein and thymolphthalein. Experimental results and theoretical analysis indicated that the response behaviors of the optodes' membranes in concentrated NaOH solutions were diffusion-independent and still complied with the pseudo-first-order kinetics. In addition, two data analysis methods for determination were presented. One was directly based on the reduced absorbance: the other was based on the discoloring kinetic constant. It was found that the latter could perform a rapid (60 s) and reliable (relative standard deviation: 2.6%) determination for high basicity.

A new flow field and its two-dimension model for polymer electrolyte membrane fuel cells (PEMFCs)

A new flow field was designed to search flow fields fitting polymer electrolyte membrane fuel cells (PEMFCs) better due its extensible. There are many independent inlets and outlets in the new flow field. The new flow field we named NINO can extend to be more general when pressures at the inlet and outlet vary and some usual flow fields will be obtained. A new mathematical model whose view angle is obverse is used to describe the flow field.

人参四逆汤生物碱和皂苷成分的研究

研究人参四逆汤的有效成分。方法 :利用软电离质谱技术 ,对人参四逆汤的有效成分进行鉴定。结果 :从人参四逆汤水煎液中分析和鉴定了人参皂苷Ra1,Ra2 ,Rb1,Rb2 ,Rb3 ,Rc ,Rd ,Re,Rg1,Rg2 ,Rg3 ,Rf等 12种人参皂苷 ;苯甲酰中乌头碱 (BM )、苯甲酰乌头碱 (BA)、苯甲酰次乌头碱 (BH)、尼奥灵 (NL)、附子灵 (FL)、14 乙酰基塔拉地萨敏 (AT)、苯甲酰次乌头碱亚油酸酯 (HAL)、苯甲酰去氧乌头碱亚油酸酯 (HAO)、苯甲酰次乌头碱棕榈酸酯 (HAP)、塔拉地萨敏 (TS)等 10种二萜生物碱。结论 :含有脂肪酸酯型生物碱的提取组分具有抗休克作用 ,含有人参皂苷的提取组分具有明显的负性肌力作用。

Matrix effects in flow injection-inductively coupled plasma mass spectrometry

Matrix effects in now injection (FI) inductively coupled plasma mass spectrometry has been studied,and the results have been compared with those of continuous nebulization. The matrix element As and nu with higher ionization potential ( > 9eV) have enhancement effect on the analyte signal,and the heavier the analyte mass, the smaller the enhancement effects by Fl. The matrix elements Cu, In, Li, Na and Pb with lower ionization potential have suppression effect on the analyte signal. The heavier the matrix element mass, the more severe the suppression effects. The heavier the analyte mass, the smaller the suppression effects. The higher ionization potential of analyte, the more severe the suppression effects. Compared with continuous nebulization, the degree of suppression effect is smaller and the degree of the enhancement effect is larger by Fl.

Automorphism group algorithm in computer-aided structure elucidation

It is necessary to generate automorphism group of chemical graph in computer-aided structure eluciation. In this paper, an algorithm is developed by all-path topological symmetry algorithm to build automorphism group of chemical graph. A comparison of several topological symmetry algorithm reveals that all-path algorthm can yield correct of class of chemical graph. It lays a foundation for ESESOC system for computer-aided structure elucidation.

计算机辅助结构解析中自同构群的生成算法

在结构解析过程中，自同构群的生成是必须的。通过全通道拓朴等价性算法，得到了化合物的自同构群，并比较了几种拓扑等价性算法，结果发现，全通道算法能够正确划分化合物的结构图，从而为ＥＳＥＳＯＣ系统的立体异构体穷举生成奠定了基础。

Preparation and spectra study of TiO2 gel doped with fluorescein

TiO2 gel doped with fluorescein was prepared by a sol-gel method, and the fluorescence of fluorescein and its effect on formation of the: gel were investigated with absorption, fluorescence, IR spectroscopies and TG-DTA analysis. The results indicated that FL incorporated into TiO2 gel had exhibited big changes compared to that in ethanol solution both in the absorption and the emission spectra, and the formation of TiO2 gel was influenced greatly by FL.

Voltammetric behavior of tetracine on glassy garbon electrode and its application

The anodic voltammetric behavior of anaesthetic tetracine and its application were studied. In 0.1 mol/L HClO4 solution, the potential of anodic peak for tetracine is 1.04 V(vs. Ag/AgCl) at a glassy carbon electrode. A linear relationship between the peak height and the concentration of tetracine in the range of 5 x 10(-4) similar to 1 x 10(-1) g/L was obtained. The peak current decreases with the decreasing acidity of the solution. the mehtod has been used for the direct determination of tetracine in injections. The average recoveries of tetracine in urine samples were 98.5%. The mechanism of the electrode reaction was also discussed.

丁卡因在玻碳电极上的伏安行为及测定

对丁卡因在玻碳电极上的伏安行为进行了研究,发现在0.1mol/L高氯酸溶液中,于1.04V(vs.Ag/AgCl)左右产生一个与丁卡因呈良好线性关系的阳极氧化伏安峰,大多数金属离子和20多种有机生化物质不干扰测定.方法用于注射针剂和加标尿样中丁卡因的测定,结果满意,对电极反应也进行了初步探讨.

荧光素掺杂的TiO_2凝胶的制备及光谱研究

近些年来，溶胶－凝胶(Sol-Gel)方法作为一种软化学合成方法具有很多优点［1］，例如制作简单、烧结温度低，制得样品稳定、坚韧，制备灵活性高等。作为一种常用的染料，荧光素(FL)常用于研究非线性光学。利用Sol-Gel法可以很好地将染料分子固定在光…