Application of an integrated microchip system with capillary array electrophoresis to optimization of enzymatic reactions

In this work, a combination of complementary metal-oxide semiconductor (CMOS) microchip system with capillary array electrophoresis (CAE) is demonstrated as a system for optimizing conditions for enzymatic reaction. Dimethylacridinone (DDAO)-phosphate substrate and alkaline phosphatase conjugate were selected for the enzymatic reaction, which was applicable to the enzyme-linked immunosorbent assay (ELISA) technique. Laser-induced fluorometry with a miniature semiconductor laser was used to detect the enzymatic products. The speed of the enzymatic reaction between the DDAO-phosphate and the alkaline phosphatase conjugate was investigated as a function of reaction time. The microchip-CAE detection system could determine the pH condition and the concentration of enzyme that are suitable for rapid and low-cost analysis. This result shows the feasibility of using the microchip-CAE system for application to miniaturized screening systems.     

N-TiO2/ZnO复合纳米管阵列的掺杂机理及其光催化活性

以ZnO纳米柱阵列为模板, 采用溶胶-凝胶法制备出TiO2/ZnO和N掺杂TiO2/ZnO的复合纳米管阵列. 扫描电镜(SEM)、X射线光电子能谱(XPS)和紫外-可见漫反射吸收光谱(UV-Vis)的结果表明: 两种阵列的纳米管均为六角形结构, 直径约为100 nm, 壁厚约为20 nm; 在N-TiO2/ZnO复合纳米管阵列中, 掺入的N离子主要是以N-Ox、N-C和N-N的形式化学吸附在纳米管表面, 仅有少量的N离子以取代式掺杂的方式占据TiO2晶格O的位置; 表面N物种形成的表面态能级和取代式掺杂导致带隙的窄化, 增强了纳米管阵列的光吸收效率, 促进了光生载流子的分离. 光催化实验结果表明, N离子的掺杂有利于N-TiO2/ZnO复合纳米管阵列光催化活性的提高.     

Fused silica capillary tube isotachophoresis using a multichannel photodiode array detector

Isotachophoresis carried out in a 0.25 mm i.d. fused-silica capillary tube yielded high resolution, compared with that in a fluorinated ethylene-propylene polymer tube. The use of an ultraviolet-visible multichannel spectrophotometer with photodiode array as detector together with a cross flow cell (volume 0.01 μl) was investigated. The system was successfully applied to the analysis of cationic dyes such as neutral red, bismarck brown, and basic fuchsine.     

Novel Fabrication of Conductive Polymers Contained Micro‐Array Gas Sensitive Films Using A Micromanipulation Method

A novel method for fabricating a micro gas sensor film on an indium tin oxide (ITO) electrode patterned using micro‐machining technology was developed. A micromanipulation system equipped with a counter electrode (Au; Ø10 μm) and a microsyringe, which was connected to a microinjection system, was first constructed. With this system, micro gas sensor arrays could be successfully prepared on ITO electrodes. Two kinds of micro gas sensor films were prepared, based on polythiophene (PTh) and poly(3‐n‐dodecylthiophene) (PD). The response behavior of conventional PTh and micro‐PTh films against NH₃ at three different operating temperatures (25, 40 and 60 °C) was investigated by measuring the resistance of the film. With the micro‐PTh film, a reversible response was observed against NH₃ when measured at 40 and 60 °C. In addition, the responsive characteristics of the microsensor films against different testing gases were examined at the three operating temperatures. The resistance of the microsensor films of PTh and PD changed considerably, depending on the type of testing gas, allowing these sensor films to be used for the detection of various gases. Furthermore, the microsensor films had a high stability compared with conventional films prepared from the same polymer.     

薄层色谱-紫外可见分光光度法同时测定食品中的苏丹红Ⅰ～Ⅳ

建立了测定食品中苏丹红色素含量的新方法——薄层色谱-紫外可见分光光度法,对影响测定的因素如样品预处理方式、展开剂等进行了讨论,检测苏丹红Ⅰ~Ⅳ的线性范围分别为0.5~14μg/mL,0.5~10μg/mL,0.5~15μg/mL,0.5~15μg/mL,线性相关系数均为0.999,检出限均为0.05μg/mL。该方法测定结果与国家标准方法测定结果基本一致。     

超高效合相色谱法快速检测塑料食品接触材料中13种紫外吸收剂

建立了一种同时检测塑料食品接触材料中13种紫外吸收剂的超高效合相色谱法。以甲醇为溶剂对塑料食品接触材料样品进行超声提取，经C18固相萃取柱净化，过0.22 μm有机滤膜，采用超高效合相色谱仪分析。选择ACQUTY UPC² HSS C18 SB色谱柱（150 mm×3.0 mm，1.8 μm），以超临界二氧化碳为流动相，异丙醇为改性剂进行梯度洗脱，在最优色谱条件下，13种紫外吸收剂能够在4 min内实现有效分离。结果表明，在各自线性范围内，13种紫外吸收剂的线性关系良好，标准曲线相关系数不低于0.9985，检出限（S/N=3）为0.05~0.15 mg/kg，加标回收率为86.8%~115.7%，相对标准偏差为0.73%~5.61%。该方法快速简便，准确可靠，同时大大减少了有机溶剂的消耗，可用于塑料食品接触材料中13种紫外吸收剂的快速检测。     

超声条件下芳基格氏试剂与4-烷基苯乙酮的反应

二芳基乙烯;超声条件下芳基格氏试剂与4-烷基苯乙酮的反应     

The detection of formaldehyde in textiles using interdigitated microelectrode array diffusion layer titration with electrogenerated hypobromite

An interdigitated microelectrode array (IDA) was applied to the determination of formaldehyde released from textiles produced in industry. The proposed method is based on formaldehyde reaction with hypobromite which is formed in weakly basic media by control current electrooxidation of bromide on the generator segment of the IDA array. The unreacted hypobromite diffuses through the gap between individually polarisable IDA segments and it is amperometrically detected on the collector segment of the IDA. The efficiency of this nonconvective transfer process in the absence of formaldehyde was substantially higher (78%) in comparison with that when using the rotating ring disc electrode. The influence of the added formaldehyde on the transfer process can be utilised to develop a simple and sensitive analytical procedure for formaldehyde detection with a detection limit of 4×10⁻⁶ mol dm⁻³.     

过碳酸钠-醋酸酐作用下的Baeyer-Villiger反应

在醋酸酐介质中, 过碳酸钠可以与酮进行Baeyer-Villiger反应, 将它们氧化成相应的酯。其中脂环酮的反应结果较好, 环内酯的产率约为80%。芳香酮除芳环被活化的以外, 效果欠佳。当反应施加超声辐射后可显著加快反应速度, 并对过碳酸钠的作用机理进行了讨论。