微全分析系统专用微型电源的研制

芯片毛细管电泳(Chip-CE)是当前微全分析系统(μ-TAS)中最活跃的领域和发展前沿.Chip-CE包括微芯片、高压电源和检测器等3个主要部分.     

微全分析系统中的电色谱分离技术

微全分析系统(μ-TAS)近年来发展非常迅速,出现了各种各样思路新颖,设计独特的芯片分析系统。本文着重从分离模式方面介绍了μ-TAS的一个新的发展方向——电色谱。由于电色谱技术兼具高效液相色谱的高选择性和毛细管电泳的高效性,因此具有广阔的应用前景。     

聚二甲基硅氧烷/玻璃微流控芯片永久性粘合方法及其微通道表面改性研究及其应用

近年来,聚二甲基桂氧烷[Poly(dimethylsilloxane),PDMS]基质微流控芯片因其透光性能好,价格便宜,加工容易,适合大规模生产,成为微全分析系统(Micro total analysis system,μ-TAS)发展的一个热点^[1].PDMS易于复制微通道形状,且具有较高的保真度,省去了玻璃芯片刻蚀的复杂过程;而玻璃具有易于集成功能单元,散热性能好的优点,PDMS-玻璃杂合微流控芯片同时结合了PDMS和玻璃的优点,具有良好的发展前景^[2].     

微型全分析系统中的电化学检测方法

结合微型全分析系统（μ-TAS)的需要和特点,根据电化学检测的原理和应用特点,阐述了含电化学检测器的微芯片系统的设计与制作,综述了微型全分析系统中安培法、电导法、电位法的应用和研究的最新进展,并分析了电化学检测做芯片的发展趋势。     

第四届全国微全分析系统学术会议第一轮通知

第四届全国微全分析系统学术会议（μ-TAS2007）将于2007年6月23—25日在大连举行。本届会议由中国化学会、国家自然科学基金委员会化学部主办，中国科学院大连化学物理研究所承办，大连理工大学协办。林炳承教授为会议主席。     

第二届沈阳国际微流控学研讨会暨第五届全国微全分析学术会议（第一轮通知）

由中国化学会、国家自然科学基金委员会联合主办,江苏省化学会负责协办的“第二届沈阳国际微流控学研讨会暨第五届全国微全分析学术会议（μ-TAS2008）”将于2008年11月1日至4日在南京召开。本次大会由南京大学筹办,由陈洪渊院士任大会主席。会议邀请国内外从事微纳流控学研究的著名科学家及学者参加,并在全世界范围内征文,     

SARS 3CL蛋白酶同源二聚化与底物结合互为别构调控因素

研究了严重急性呼吸系统综合症(SARS)冠状病毒3C-Like蛋白酶(3CLpro)在存在底物或抑制剂时的二聚体形成情况. 通过测定酶活性随酶浓度的变化, 拟合出在底物存在下酶二聚体的解离常数约为0.94 μmol·L-1, 小于纯蛋白酶的二聚体解离常数(14.0 μmol·L-1), 表明底物对二聚体的形成具有增强作用. 选用与底物具有类似结合方式的靛红类抑制剂N-萘甲基靛红-5-甲酰胺(5f), 利用超速离心沉降速率方法定量测定了SARS 3CL蛋白酶单体和二聚体在不同浓度5f时的含量, 发现5f同样具有诱导二聚体形成的能力. 在3 μmol·L-1蛋白酶浓度下测定得到诱导二聚的EC50 值(半数有效浓度)约为1 μmol·L-1, 说明二聚体中只有一个单体与抑制剂结合. 研究结果表明, 随着底物浓度的升高, SARS 3CL蛋白酶会形成更多的二聚体, 而二聚体含量的提高又反过来提高酶的活性, 这种双向别构调控机制有可能是病毒用来调控多聚蛋白水解速率和组装时机的一种方法.     

微流控芯片用于单细胞分析

微流控芯片通道内径一般约10~50 μm.典型哺乳类动物细胞直径一般为8~30 μm,体积为87 fL~4 pL.     

顶空气相色谱-质谱法同时测定蜂蜜中57种挥发性有机溶剂残留

建立了顶空气相色谱-质谱(HS-GC/MS)同时测定蜂蜜中57种挥发性有机溶剂(包括烷烃类、芳香烃类、醇类、酮类、酯类、醚类)残留量的分析方法。蜂蜜样品在密封的顶空瓶中用水溶解后,在顶空仪中于80 ℃下平衡30 min,使气-液两相达到动态平衡。采用DB-624毛细管色谱柱(60 m×0.25 mm×1.40 μm)对57种有机溶剂进行分离,GC/MS测定,外标法定量。该方法对于烷烃类、芳香烃类和醚类挥发性有机溶剂在0.005～0.2 μg、酯类0.05～2.0 μg、酮类0.5～20 μg、醇类2.5～100 μg范围内线性关系良好,相关系数均大于0.996。对于烷烃类、芳香烃类和醚类挥发性有机溶剂在1.0～20 μg/kg、酯类10～200 μg/kg、酮类100～2000 μg/kg、醇类500～10000 μg/kg添加范围内的平均添加回收率为61.0%～113.1%,相对标准偏差为1.9%～9.8%。对于烷烃类、芳香烃类和醚类挥发性有机溶剂的检出限为1.0 μg/kg、酯类10 μg/kg、酮类100 μg/kg、醇类500 μg/kg。该方法操作简单、快速,灵敏度和准确度高,适用于蜂蜜样品中多种挥发性有机溶剂残留量的同时检测。     

芯片毛细管电泳-安培检测系统

由于安培检测具有的高灵敏度、低成本、低能耗、易集成化便携化、与微加工技术匹配等特点,芯片毛细管电泳-安培检测系统（μCE-AD）的研究近年来得到人们广泛的关注。本文结合本课题组的研究工作,对近年来μCE-AD的研究进展进行评述;重点讨论了近年来在芯片的设计、集成化电极的制备、消除分离电压的干扰等方面的进展;同时介绍了利用分离电场拓展检测范围、阵列电极和阵列通道、化学修饰电极的应用、新型进样技术和试样预处理等方面的新成就;最后展望了未来μCE-AD的发展趋势。     

Recombinant drugs-on-a-chip: The usage of capillary electrophoresis and trends in miniaturized systems – A review

We present here a critical review covering conventional analytical tools of recombinant drug analysis and discuss their evolution towards miniaturized systems foreseeing a possible unique recombinant drug-on-a-chip device. Recombinant protein drugs and/or pro-drug analysis require sensitive and reproducible analytical techniques for quality control to ensure safety and efficacy of drugs according to regulatory agencies. The versatility of miniaturized systems combined with their low-cost could become a major trend in recombinant drugs and bioprocess analysis. Miniaturized systems are capable of performing conventional analytical and proteomic tasks, allowing for interfaces with other powerful techniques, such as mass spectrometry. Microdevices can be applied during the different stages of recombinant drug processing, such as gene isolation, DNA amplification, cell culture, protein expression, protein separation, and analysis. In addition, organs-on-chips have appeared as a viable alternative to testing biodrug pharmacokinetics and pharmacodynamics, demonstrating the capabilities of the miniaturized systems. The integration of individual established microfluidic operations and analytical tools in a single device is a challenge to be overcome to achieve a unique recombinant drug-on-a-chip device.     

Miniaturized Sequencing Gel System for Quick Analysis of DNA by Hydroxyl Radical Cleavage

We described a simple and quick miniaturized sequencing gel system for DNA analysis. Two major modifications were made to the previously reported miniaturized DNA sequencing gel system to achieve high-resolution hydroxyl radical cleavage analysis: including formamide in the miniaturized gel and providing uniform heating during electrophoresis. Our method enables one to reduce the cost for chemicals and to significantly reduce electrophoresis time. Furthermore, minimal gel handling simplifies the entire process. We show that the resolution of DNA fragments obtained by hydroxyl radical cleavage for the miniaturized gel is similar to that of a large conventional sequencing gel.     

Supported capillary membrane sampling-gas chromatography on a valve with a pulsed discharge photoionization detector

The objective of this study was to develop and evaluate a simple miniaturized approach to gas chromatography termed supported capillary membrane sampling-gas chromatography on a valve (SCMS-GCOV). The prototype instrument uses a pulsed discharge photoionization detector (PDPID) as the GC detector. Two different analyzers were constructed. The first used a bench scale SCMS-GC. The second was a miniaturized SCMS-GCOV analyzer. The SCMS-GCOV analyzer was used to monitor the concentrations of trihalomethanes (THM4) in drinking water. Details are given for the construction of the SCMS-GC-PDPID and the SCMS-GCOV-PDPID analyzers. The results of method detection limit, accuracy and precision studies are reported for analysis of THM4 and are compared to other methods of THM4 analysis. Side-by-side comparison studies are conducted between the SCMS-GCOV and USEPA 502.2 with promising results.     

High-throughput microfluidic sample-introduction systems

We give an overview on recent developments in high-throughput microfluidic sample-introduction techniques based on a capillary sampling probe and a slotted-vial array (SVA). We discuss the advantages and the potential of SVA-based sample-introduction systems as well as their applications in miniaturized flow-injection analysis, sequential-injection analysis, capillary electrophoresis and liquid-liquid extraction. We illustrate the advantages and the potential of SVA-based sample-introduction systems using results obtained recently.     

Immersed single-drop microextraction interfaced with sequential injection analysis for determination of Cr(VI) in natural waters by electrothermal-atomic absorption spectrometry

Single-drop microextraction (SDME) and sequential injection analysis have been hyphenated for ultratrace metal determination by Electrothermal-Atomic Absorption Spectrometry (ETAAS). The novel method was targeted on extraction of the Cr(VI)-APDC chelate and encompasses the potential of SDME as a miniaturized and virtually solvent-free preconcentration technique, the ability of sequential injection analysis to handle samples and the versatility of furnace autosamplers for introducing microliter samples in ETAAS.     

Comparison of micro-LC and capillary zone electrophoresis for the analysis of thiols

Micro-LC and capillary zone electrophoresis (CZE) are two of the most rapidly developing, miniaturized separation techniques in analytical science. In the present paper, both techniques were comparatively evaluated for the determination of several important thiols derivatized with the fluorogenic reagent SBD-F. Different parameters, such as selectivity, sensitivity, analysis time and efficiency, influence of column length, CZE buffer concentration, and voltage were thus analyzed and discussed. Both techniques are recommended for the analysis of thiols in biological samples.     

Microfluidic systems in clinical diagnosis

The use of microfluidic devices is highly attractive in the field of biomedical and clinical assessments, as their portability and fast response time have become crucial in providing opportune therapeutic treatments to patients. The applications of microfluidics in clinical diagnosis and point-of-care devices are continuously growing. The present review article discusses three main fields where miniaturized devices are successfully employed in clinical applications. The quantification of ions, sugars, and small metabolites is examined considering the analysis of bodily fluids samples and the quantification of this type of analytes employing real-time wearable devices. The discussion covers the level of maturity that the devices have reached as well as cost-effectiveness. The analysis of proteins with clinical relevance is presented and organized by the function of the proteins. The last section covers devices that can perform single-cell metabolomic and proteomic assessments. Each section discusses several strategically selected recent reports on microfluidic devices successfully employed for clinical assessments, to provide the reader with a wide overview of the plethora of novel systems and microdevices developed in the last 5 years. In each section, the novel aspects and main contributions of each reviewed report are highlighted. Finally, the conclusions and future outlook section present a summary and speculate on the future direction of the field of miniaturized devices for clinical applications.     

A Miniaturized Voltammetric Electronic Tongue

Abstract

A miniaturized electronic tongue based on pulsed voltammetry has been developed. It was made by inserting three types of wires acting as working electrodes (gold, platinum, and rhodium; diameter 0.25 mm) into a platinum tube acting as a counter electrode (diameter 2 mm; length 4 mm). The arrangement was connected to a potentiostat controlled by a computer. Due to the small size of the miniaturized electronic tongue, and since no reference electrode is used, the setup is very simple and convenient. In order to characterize the analytical possibilities of the miniaturized electronic tongue, some initial experiments were performed. These include the determination of trace amounts of cadmium and lead (in the µM range) in 5 µL samples. Furthermore, the setup was placed under the real tongue of a volunteer to follow saliva composition during exercise.     

Miniaturized detectors for a chemical analysis system

Recently, several studies about miniaturized chemical analysis systems fabricated with micromachining methods were reported. These systems have some advantages, such as fast response, small amount of sample, and low consumption of reagents, as compared with the conventional system. With such a small system, design of the detector units is very important to monitor analytical performance. This paper introduces some examples of micromachined detectors for miniaturized chemical analysis systems.     

Strengths and weaknesses of in-tube solid-phase microextraction: A scoping review

In-tube solid-phase microextraction (in-tube SPME or IT-SPME) is a sample preparation technique which has demonstrated over time its ability to couple with liquid chromatography (LC), as well as its advantages as a miniaturized technique. However, the in-tube SPME perspectives in the forthcoming years depend on solutions that can be brought to the environmental, industrial, food and biomedical analysis. The purpose of this scoping review is to examine the strengths and weaknesses of this technique during the period 2009 to 2015 in order to identify research gaps that should be addressed in the future, as well as the tendencies that are meant to strengthen the technique.