Green micro total analysis systems (GμTAS) for environmental samples

Micro total analysis systems (μTAS) which have received great interest in the recent years and successfully employed for fluid processing in microchannels at microliter levels are powerful alternatives to traditional macroscale analytical systems. Unique benefits arise in the scaling down of traditional macroscale systems, including significant decrease of reagent, sample and energy consumption, faster and cost-effective analytical processes and lowered analysis time. Furthermore, μTAS can be efficiently automated which leads to higher throughput and multiplexing.In this review paper, mainly green aspects of μTAS such as reducing of the volume of sample and solvents, using green solvents in μTAS, minimization of the generated waste and cost-effective processes for μTAS are discussed. The recent applications of green μTAS in the detection of various pollutants including heavy metals, pharmaceutical compounds, and dye compounds in environmental samples such as wastewaters, river waters are also demonstrated and highlighted.     

毛细管电泳技术和应用新进展

毛细管电泳（CE）是当前分析化学前沿领域和研究重点之一。本文对细管电泳技术－分离模式、进样技术和检测器为线索对最近的研究进展进行了综述,探讨了各种模式和技术的分析效率。并介绍了CE很有实用价值的几个方面的应用,包括在基因工程和单细胞分析中的突出表现,在手性分离和小分子离子分析方面的广泛应用。     

Integration of electrochemistry in micro-total analysis systems for biochemical assays: Recent developments

Micro-total analysis systems (μTAS) integrate different analytical operations like sample preparation, separation and detection into a single microfabricated device. With the outstanding advantages of low cost, satisfactory analytical efficiency and flexibility in design, highly integrated and miniaturized devices from the concept of μTAS have gained widespread applications, especially in biochemical assays. Electrochemistry is shown to be quite compatible with microanalytical systems for biochemical assays, because of its attractive merits such as simplicity, rapidity, high sensitivity, reduced power consumption, and sample/reagent economy. This review presents recent developments in the integration of electrochemistry in microdevices for biochemical assays. Ingenious microelectrode design and fabrication methods, and versatility of electrochemical techniques are involved. Practical applications of such integrated microsystem in biochemical assays are focused on in situ analysis, point-of-care testing and portable devices. Electrochemical techniques are apparently suited to microsystems, since easy microfabrication of electrochemical elements and a high degree of integration with multi-analytical functions can be achieved at low cost. Such integrated microsystems will play an increasingly important role for analysis of small volume biochemical samples. Work is in progress toward new microdevice design and applications.     

Sample introduction techniques for microchip electrophoresis: A review

The number of applications of microfluidic analysis systems continues to increase, along with the variety of substrate materials and complexity of the devices themselves. One of the most common features of these devices that has remained relatively unchanged, however, is the introduction of a sample mixture into a separation channel so that individual components can be separated by electrophoresis. Whether a relatively simple mixture of amino acids or a more complex sample of DNA fragments extracted and amplified on-chip, the ability to reliably and reproducibly inject a representative sample is arguably the most significant requirement for an electrophoretic micro total analysis system (μTAS). This review will focus on the different methods reported for sample introduction in microchip electrophoresis, highlighting both pressure-driven and electrokinetic techniques, with an emphasis on the methods employed in μTAS applications.     

Circumventing air bubbles in microfluidic systems and quantitative continuous-flow PCR applications

Polymerase chain reaction (PCR) is an essential part of research based on genomics or cell analysis. The development of a microfluidic device that would be suitable for high-temperature-based reactions therefore becomes an important contribution towards the integration of micro-total analysis systems (μTAS). However, problems associated with the generation of air bubbles in the microchannels before the introduction of the assay liquid, which we call the “initial start-up” in this study, made the flow irregular and unstable. In this report, we have tried to address these problems by adapting a novel liquid-flow method for high-temperature-based reactions. A PDMS-based microfluidic device was fabricated by soft-lithography techniques and placed on a cartridge heater. The generation of the air bubbles was prevented by introducing the fluorinated oil, an inert and highly viscous liquid, as the cap just before the introduction of the sample solutions into the microchannels. The technique was applied for continuous-flow PCR, which could perform PCR on-chip in a microfluidic system. For the evaluation of practical accuracy, plasmid DNA that serves as a reference molecule for the quantification of genetically modified (GM) maize was used as the template DNA for continuous-flow PCR. After PCR, the products were collected in a vial and analyzed by gel electrophoresis to confirm the accuracy of the results. Additionally, quantitative continuous-flow PCR was performed using TaqMan technology on our PCR device. A laser detection system was also used for the quantitative PCR method. We observed a linear relationship between the threshold cycle (Ct) and the initial DNA concentration. These results showed that it would be possible to quantify the initial copies of the template DNA on our microfluidic device. Accurate quantitative DNA analysis in microfluidic systems is required for the integration of PCR with μTAS, thus we anticipate that our device would have promising potential for applications in a wide range of research.     

Trends in Microfluidics with Complex Fluids

The rapid developments in biotechnology create a great demand for fluid handling systems on the nano‐ and picoliter scale. The characterization of minute quantities of DNA or protein samples requires highly integrated, automated, and miniaturized “total analysis systems” (μ‐TAS). The small scales necessitate new concepts for devices both from a technological and from a fundamental physical point of view. Here, we describe recent trends in both areas. New technologies include soft lithography, chemical, and topographical structuring of surfaces in order to define pathways for liquids, as well as electrowetting for manipulation purposes. Fundamentally, the interplay between geometric confinement and the size of biological macromolecules gives rise to complex dynamic behavior. The combination of both fluorescence imaging and scattering techniques allows for detailed insight into the dynamics of individual molecules and into their self‐assembly into supramolecular aggregates.     

DNA/银纳米簇在分析检测中的应用

银纳米簇(AgNCs)为几个到数十个原子所组成的聚集体,核尺寸小于2 nm,具有优异的物理化学性质,常以聚合物、蛋白质、DNA等作为模板采用化学合成法制备,其中以DNA为模板合成的AgNCs(DNA/AgNCs)是一种新型的发光纳米材料,其突出的荧光特性和良好的生物相容性,被应用于纳米传感器、细胞标记与检测等多种分析领...     

Integrating amperometric detection with electrophoresis microchip devices for biochemical assays: recent developments

Recent advances in microfluidic systems, particularly in the Micro Total Analysis System (μTAS) or Lab On a Chip (LOC), drive the current analysis tools and equipment towards miniaturization, rapid at-line testing and mobility. The state-of-the-art microfluidic technology targets a wider range but smaller volumes of analytes, making the analytical procedure relatively easier and faster. This trend together with faster electronics and modern instrumentation systems will make real-time and in situ analysis a definite possibility. This review focuses on microchip capillary electrophoresis with amperometric detection (MCE-AD) for the detection of DNA and other electroactive analytes. The problems associated with the microchip design, in particular the choice of materials and the configuration of electrodes are discussed thoroughly and solutions are proposed. Significant developments in the related areas are also covered and reviewed critically.     

TAS‐Indolid und TAS‐Carbazolid: Strukturen von [TAS]+[IndHInd]− und [TAS]+[Carb]−·½CarbH

TAS Indolide and TAS Carbazolide: Structures of [TAS]⁺[IndHInd]^? and [TAS]⁺[Carb]^?·½CarbH From the reaction of TAS‐fluoride [(Me₂N)₃S]⁺[Me₃SiF₂]^? with trimethylsilyl‐indole and trimethylsilyl‐carbazole TAS‐indolide and TAS‐carbazolide are formed. During crystallisation partially protonation to indole and carbazole occurs, resulting in the formation of [TAS]⁺[IndHInd]^? ( 3a ) and [TAS]⁺[Carb]^?·½CarbH ( 5a ) according to X‐ray analysis.     

阿达玛变换显微图象分析系统在乳腺肿瘤细胞DNA倍性分析中的应用研究

以正常人外周静脉血淋巴细胞为标准二倍体细胞，以吖啶橙为细胞DNA荧光探针，用阿达玛变换显微图象分析仪测定了六例乳腺肿瘤的细胞DNA含量（倍性），分析结果与病例学诊断结论吻合，表明该仪器可望用于乳腺癌的诊断和预后研究．研究结果还表明：乳腺肿瘤细胞DNA倍性与核面积（象素）呈显著正相关．     

DNA序列特征的统计分析

介绍了近年来在多种学科领域对DNA碱基序列的研究中发展起来的定量分析符号序列的方法,归纳了将碱基与数字对应起来的规则和进行统计分析的方法．并给予一定的评价。DNA分子包涵了丰富的化学信息和生物信息,对于DNA序列的统计分析显得非常重要。将DNA序列表达成数字信号通常有从一维到四维4种不同维数空间的映射方式,其相应的统计方法有均方根涨落、熵近似方法、傅立叶变换和小波变换等,各种方法从多个角度多个层次来分析揭示了DNA序列的结构规律。     

Anionic triazine systems

The synthesis of TAS+ C3N3F4- (1) (TAS+ = (Me2N)3S+) and the reactions of 1 with Me3SiOSiMe3 and Me3SiCF3 to give TAS+ C3N3F2O- (2) and TAS+[(NCF)(NCCF3)(NC(CF3)(2)]- (4) are reported. An isomer of 4, TAS+[(NCCF3)2(NCFCF3)]-, compound 6, was obtained by fluoride ion addition to (CF3CN)3. From the reactions with Me3SiNMe2 neutral fluoroamino triazines C3N3Fn(NMe2)(n-1) (n = 1, 2) were isolated. Possible reaction pathways are discussed, the X-ray structures of 1, 2, 4 and 6 were determined.     

Spectral Studies and Cathodic Reduction of some Thiazolylazo Derivatives

The structure of the 2-thiazolylazosalicylic acid molecule, TAS, has been determined by means of quantum SCF-CI calculations. The ionization potential and the electron affinity of TAS molecule were calculated to have the values 9.057 and 2.56 eV respectively. The solvation energies in different solvents, and the bond orders of the TAS molecule were calculated for the neutral state, the oxidized form (the cation) and the reduced form (the anion). Mixed solvent studies were carried out with TAS and 2-benzothiazolylazosalicylic acid (BTAS), using polar solvents (EtOH and MeOH) to confirm the formation of a solvent-solute complex. The azo group in the TAS molecule nas a considerable contribution in the SCFLUMO; thus cathodic reduction has been focused on the azo group and was verified experimentally by cathodic reduction.     

微流控芯片技术在生命科学研究中的应用

微流控芯片最初起源于分析化学领域,是一种采用精细加工技术,在数平方厘米的基片,制作出微通道网络结构及其它功能单元,以实现集微量样品制备、进样、反应、分离及检测于一体的快速、高效、低耗的微型分析实验装置.随着微电子及微机械制作技术的不断进步,近年来微流控芯片技术发展迅猛,并开始在化学、生命科学及医学器件等领域发挥重要作用.本文首先简单介绍了微流控芯片制作材料和工艺,然后主要阐述了其在蛋白质分离、免疫分析、DNA分析和测序、细胞培养及检测等方面的应用进展.     

Single cell analysis at the nanoscale

The fundamental life processes such as signal transduction, intracellular trafficking, protein degradation, and DNA repair often occur in nanometric subcellular compartments. It is essential to conduct single cell analysis specifically at the nanoscale to fully understand the critical cellular processes while providing important medical applications. However, there are great challenges in achieving high spatial resolution in single cells for uncovering spatial heterogeneity, high sensitivity for biomolecule detections and high specificity in complicated cellular environment. In this tutorial review, we survey recent progress toward single cell analysis at the nanoscale by emphasizing how the advancement in nanotechnology has brought a plethora of nanotools to interrogate single cells with high spatiotemporal resolutions. In particular, analysis principle, nanoscale probe fabrication, high resolution cellular analysis, data collection and processing are introduced. New cell biochemistry and biology insights revealed by the unique single cell analysis methods are highlighted. The perspectives on future opportunities and unsolved challenges are also discussed.     

Microfluidics technology for manipulation and analysis of biological cells

Analysis of the profiles and dynamics of molecular components and sub-cellular structures in living cells using microfluidic devices has become a major branch of bioanalytical chemistry during the past decades. Microfluidic systems have shown unique advantages in performing analytical functions such as controlled transportation, immobilization, and manipulation of biological molecules and cells, as well as separation, mixing, and dilution of chemical reagents, which enables the analysis of intracellular parameters and detection of cell metabolites, even on a single-cell level. This article provides an in-depth review on the applications of microfluidic devices for cell-based assays in recent years (2002–2005). Various cell manipulation methods for microfluidic applications, based on magnetic, optical, mechanical, and electrical principles, are described with selected examples of microfluidic devices for cell-based analysis. Microfluidic devices for cell treatment, including cell lysis, cell culture, and cell electroporation, are surveyed and their unique features are introduced. Special attention is devoted to a number of microfluidic devices for cell-based assays, including micro cytometer, microfluidic chemical cytometry, biochemical sensing chip, and whole cell sensing chip.     

脱氧核糖核酸电分析化学研究进展

就DNA电分析化学研究及其应用方面进行综述，主要叙述了DNA的各种电分析化学方法，以及DNA电化学传感器的原理，应用以及发展，本文引用文献77篇。     

吖啶橙-细胞DNA荧光抑制法筛选抗癌药物

在DNA荧光法‘’‘初步筛选抗癌药物的实验中,漠化乙锭（EB）是常用的荧光探针,其本身荧光板弱,但能与双链DNA发生专一性插入作用,使荧光大幅度地增强．但EB不能进入完整的细胞膜［’j．对陕橙（AO）常用于细胞内DNA和RNA的定量测定,并能用于活细胞染色;AO与核酸的结合方式有2种：一种是在嵌入核酸双链的碱基对之间形成AO－DNA复合物,另一种是与单链核酸的磷酸发生静电间相互作用,形成AO－RNA复合物．如用蓝光激发,前者发射峰波长为530urn的绿色荧光,后者发射峰波长为640urn的红色荧卅’‘．本文提出一种对细胞周期非…     

DNA分子构成及其分析测定方法

ＤＮＡ是生物体主要的遗传物质,有关ＤＮＡ的研究是揭示生物遗传奥秘的基础。在对ＤＮＡ的分子构型－双螺旋结构及ＮＤＡ分子组成分析的基础上,探讨了ＤＮＡ的某些性质,论述了ＤＮＡ分析测定方法的发展过程,介绍了近几年来国际国内对ＤＮＡ分析测定的新成果及发展方向。