基于液滴技术的微流控芯片实验室

液滴微流控系统是微流控芯片领域的一个新的分支,由于其诸多独特的优势而得到了广泛的研究和报道。本文对液滴的制备和相关的操控技术,包括液滴的分裂、融合、混合、分选、存储和编码等进行了介绍,对液滴技术近年来在化学与生物化学分析等领域中的应用进行了综述,并展望了液滴微流控技术的发展前景。     

毛细管电泳分析中的富集技术及其应用

毛细管电泳（CE）具有分析速度快、分离效率高、样品消耗少、成本低廉等优点,已被应用于无机离子、有机小分子、蛋白质、核酸及细胞等的分析中。CE中最常用的检测方式是紫外检测（UV）,但由于常规进样样品体积小、检测光程短,CE-UV的灵敏度往往不能满足复杂样品中痕量物质直接分析的要求。CE中的在柱富集技术包括堆积、动态pH界面、吹扫和瞬间等速电泳等,可在很大程度上提高CE-UV的检测灵敏度;另外,固相和液相微萃取技术及其与在柱富集技术相结合应用在CE中也能净化样品基质,进一步提高富集倍数,改善分析灵敏度,从而拓宽了CE-UV在复杂样品分析中的应用范围。     

Directed antibody-engineering techniques and their applications in food immunoassays

The use of antibodies in immunodiagnostics has achieved new insights with recombinant technologies. This review summarizes the methods used to produce recombinant antibodies and those to tailor their properties. Finally, we address the advantages and the possibilities of recombinant antibodies in immunoanalytical applications through examples with the main focus on applications related to food quality and safety analysis.     

Radioanalytical and imaging techniques: Challenges and opportunities in biomedical applications

Nickel-63 is a low energy beta-emitter needing a radiochemical separation before β-counting. Several papers described the separation and the detection of ⁶³Ni in environmental samples. The method used in our work was first developed by Skwarzec and Holm. The main steps of this separation are the selective precipitation of nickel with dimethylglyoxime (DMG) and the use of the non-sorption of nickel on anion resin in hydrochloric acid solutions. In this paper, a new step is added to eliminate high quantities of calcium and magnesium phosphate disturbing the iron hydroxide precipitation step. The procedure has been applied to soft water samples: sediments, plants and fishes. The chemical yields are 60, 70 and 20%, respectively. The detection limit of ⁶³Ni by liquid scintillation spectrometer is 10 mBq.     

外泌体分离技术及其临床应用研究进展

外泌体是细胞通过胞吐过程分泌的一类粒径为30~200 nm的囊泡，其组成包括脂质双分子层以及其内部包裹的细胞来源的蛋白质、核糖核苷酸（RNA）和脱氧核糖核苷酸（DNA）等生物分子。作为一种细胞间交流的重要方式，外泌体在一系列生理和病理过程中起着至关重要的作用。由于体液环境复杂，加之自身体积小、密度低，外泌体的富集与分离对于其后续分析和功能研究至关重要。该文介绍了外泌体的研究策略、表征手段及生物学功能和临床应用研究进展，特别对外泌体的提取方法进行了详细介绍，并加以系统评述。     

Droplet microfluidics: recent developments and future applications

We report recent advances in the field of droplet-based microfluidics. Specifically, we highlight the unique features of such platforms for high-throughput experimentation; describe functional components that afford complex analytical processing and report on applications in synthesis, high-throughput screening, cell biology and synthetic and systems biology. Issues including the integration of high-information content detection methods, long term droplet stability and opportunities for large scale and intelligent biological experimentation are also discussed.     

Recent advances in SALDI-MS techniques and their chemical and bioanalytical applications

Although laser desorption mass spectrometry was introduced in the 1960s, the potential of laser mass spectrometry was not realised until the introduction of matrix-assisted laser desorption/ionisation (MALDI) in the 1980s. The technique relies on light-absorbing compounds called matrices that are co-crystallised with the analyte to achieve high ionisation and desorption efficiencies. MALDI offers a lot of advantages and is an indispensable tool in macromolecule analysis. However, the presence of the matrix also produces a high chemical background in the region below m/z 700 in the mass spectrum. Surface-assisted laser desorption/ionisation (SALDI) substitutes the chemical matrix of MALDI for an active surface, which means that matrix interference can be eliminated. SALDI mass spectrometry has evolved in recent years into a technique with great potential to provide insight into many of the challenges faced in modern research, including the growing interest in “omics” and the demands of pharmaceutical science. A great variety of materials have been reported to work in SALDI. Examples include a number of nanomaterials and surfaces. The unique properties of nanomaterials greatly facilitate analyte desorption and ionisation. This article reviews recent advances made in relation to carbon- and semiconductor-based SALDI strategies. Examples of their environmental, chemical and biomedical applications are discussed with the aim of highlighting progression in the field and the robustness of the technique, as well as to evaluate the strengths and weaknesses of individual approaches. In addition, this article describes the physical and chemical processes involved in SALDI and explains how the unique physical and electronic properties of nanostructured surfaces allow them to substitute for the matrix in energy transfer processes.     

Droplet‐based microfluidics systems in biomedical applications

Microfluidics has made a very impressive progress in the past decades due to its unique and instinctive advantages. Droplet‐based microfluidic systems show excellent compatibility with many chemical and biological reagents and are capable of performing variety of operations that can implement microreactor, complex multiple core–shell structure, and many applications in biomedical research such as drug encapsulation, targeted drug delivery systems, and multifunctionalization on carriers. Droplet‐based systems have been directly used to synthesize particles and encapsulate many biological entities for biomedicine applications due to their powerful encapsulation capability and facile versatility. In this paper, we review its origin, deviation, and evolution to draw a clear future, especially for droplet‐based biomedical applications. This paper will focus on droplet generation, variations and complication as starter, and logistically lead to the numerous typical applications in biomedical research. Finally, we will summarize both its challenge and future prospects relevant to its droplet‐based biomedical applications.     

Contactless conductivity detection for microfluidics: designs and applications

Different methods for construction of contactless conductivity detectors (CCD) for microchip electrophoresis device are described in this review. This includes three main schemes of CCD for microchips, such as (i) the detection electrodes are placed along the microchannel from outside of the microchip and they are insulated from the channel by the cover lid of microchip device; (ii) the electrodes are placed across of the microchannel in the same plane and they are insulated by thin separation channel walls and (iii) electrodes are buried in widened part of microchannel and they are insulated from solution by ultrathin layer of silicon carbide. Specific issues related to the CCD on microfluidics are discussed, such as an influence of shape and magnitude of ac voltage and placement of electrodes and their insulation. Various applications for security, pharmacological, bioassays and food analysis purposes are described.     

以亲水作用色谱为核心的液相色谱联用技术及其应用研究

亲水作用色谱(HILIC)是近年来色谱领域研究的热点之一。本文围绕复杂体系样品中亲水性组分的分离分析,综述了国际上近年 来发展的以HILIC为核心的多种液相色谱联用技术及其应用。简要介绍了HILIC的起源、定义、分离特点及其常用固定相;比较了HILIC和反相色谱(RPLC)的选择特性;针对不同层次的分离对象和分离要求,讨论了多种基于HILIC的液相色谱以及液相色谱-质谱联用技术的分离特点和适用范围。     

Development and analytical applications of multispectral imaging techniques: An overview

A multispectral imaging spectrometer is an instrument that can simultaneously record spectral and spatial information of a sample. Chemical and physical properties of the sample can be elucidated from such images. By synergistic use of an acousto-optic tunable filter and a progressive scan camera capable of snap shot recording it was possible to develop a novel imaging spectrometer with a spatial resolution of a few microns and which can record, grab and store up to 33 images per second (at a function of time) or 16 images per second (as a function of wavelength). This overview article summarizes the instrumentation development of various imaging spectrometers and their applications including its use as the detector for the determination of identity and sequences of peptides synthesized by the combinatorial solid phase method.     

Development and analytical applications of multispectral imaging techniques: an overview

A multispectral imaging spectrometer is an instrument that can simultaneously record spectral and spatial information of a sample. Chemical and physical properties of the sample can be elucidated from such images. By synergistic use of an acousto-optic tunable filter and a progressive scan camera capable of snap shot recording it was possible to develop a novel imaging spectrometer with a spatial resolution of a few microns and which can record, grab and store up to 33 images per second (at a function of time) or 16 images per second (as a function of wavelength). This overview article summarizes the instrumentation development of various imaging spectrometers and their applications including its use as the detector for the determination of identity and sequences of peptides synthesized by the combinatorial solid phase method.     

实时直接分析质谱新技术及其应用

由于不需要复杂的样品前处理过程,并具有实时、原位分析等特点,常压敞开式离子化技术成为近年来质谱研究的热点之一.实时直接分析(direct analysis in real time,DART)是近年来出现的一种常压敞开式离子化新技术,在食品安全、环境监测、爆炸物检测以及生物医药等诸多研究领域均有广泛的应用.本文简单介绍了常压敞开式离子化方法的发展,DART的基本原理和研究现状.进而介绍了我国质谱研究人员在基于DART的质谱仪器改进、联用技术以及生物药物等检测分析方面取得的新进展和新成果.     

Zirconium oxide films: deposition techniques and their applications in dye-sensitized solar cells

Zirconium oxide (ZrO₂) is acquiring considerable attention of most of the research groups and leading to a large number of publications due to its unique properties, especially in the context of emerging trends in the third generation of solar cell research. ZrO₂ films offer magnificent aspects related to physicochemical properties, and the properties are found to be dependent on synthesis methods. In the present review, various deposition techniques used to grow zirconium oxide thin films and their application to enhance the quantum efficiency of titanium oxide (TiO₂) based dye-sensitized solar cells (DSSCs) are discussed. Also, the modulated performances of DSSCs fabricated by growing the conformal ZrO₂ insulating films to retard interfacial recombination dynamics on preformed TiO₂ films are discussed.

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Optical sectioning for microfluidics: secondary flow and mixing in a meandering microchannel

Secondary flow plays a critical function in a microchannel, such as a micromixer, because it can enhance heat and mass transfer. However, there is no experimental method to visualize the secondary flow and the associated mixing pattern in a microchannel because of difficulties in high-resolution, non-invasive, cross-sectional imaging. Here, we simultaneously imaged and quantified the secondary flow and pattern of two-liquid mixing inside a meandering square microchannel with spectral-domain Doppler optical coherence tomography. We observed an increase in the efficiency of two-liquid mixing when air was injected to produce a bubble-train flow and identified the three-dimensional enhancement mechanism behind the complex mixing phenomena. An alternating pair of counter-rotating and toroidal vortices cooperated to enhance two-liquid mixing.     

Optical and electronic properties of fluorene‐based copolymers and their sensory applications

A series of novel, fluorene‐based conjugated copolymers, poly[(9,9‐bis{propenyl}‐9H‐fluorene)‐co‐(9,9‐dihexyl‐9H‐fluorene)] ( P1 ), poly[(9,9‐bis{carboxymethylsulfonyl‐propyl}fluorenyl‐2,7‐diyl)‐co‐(9,9‐dihexyl‐9H‐fluorene)] ( P2 ) and poly[(9,9‐dihexylfluorene)‐co‐alt‐(9,9‐bis‐(6‐azidohexyl)fluorene)] ( P3 ), are synthesized by Suzuki coupling reactions and their electrochemical properties, in the form of films, are investigated using cyclic voltammetry. The results reveal that the polymer films exhibit electrochromic properties with a pseudo‐reversible redox behavior; transparent in the neutral state and dark violet in the oxidized state. Among the three polymers, P2 possesses the shortest response time and the highest coloration efficiency value. These polymers emit blue light with a band gap value of around 2.9 eV and have high fluorescent quantum yields. Their metal ion sensory abilities are also investigated by titrating them with a number of different transition metal ions; all of these polymers exhibit a higher selectivity toward Fe³⁺ ions than the other ions tested with Stern–Volmer constants of 4.41 × 10⁶M^?1, 3.28 × 10⁷M^?1, 1.25 × 10⁶M^?1, and 6.56 × 10⁶M^?1 for P1 , P2 , water soluble version of P2 ( P2S ) and P3 , respectively. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013     

可激活磁共振成像纳米探针的制备及生物医学应用

在生物医学领域,磁共振成像是一种非常重要的疾病诊疗技术.近50%的磁共振检查已经涉及造影剂的应用.可激活磁共振成像纳米探针以优化信噪比为原则,借助特异性的生物分子识别作用或分子交互作用增强磁共振信号,提高了磁共振诊断的敏感性与特异性,推动着磁共振成像在生物医学领域的广泛应用.本文就目前国内外热门研究的可激活磁共振纳米探针的种类、原理等方面进行阐述,详细介绍了可激活磁共振纳米探针在生物医学上的应用,在前景方面也进行了展望.     

Digital microfluidics: a versatile tool for applications in chemistry, biology and medicine

Digital microfluidics (DMF) has recently emerged as a popular technology for a wide range of applications. In DMF, nanoliter to microliter droplets containing samples and reagents can be manipulated to carry out a range of discrete fluidic operations simply by applying a series of electrical potentials to an array of patterned electrodes coated with a hydrophobic insulator. DMF is distinct from microchannel-based fluidics as it allows for precise control over multiple reagent phases (liquids and solids) in heterogeneous systems with no need for complex networks of connections, microvalves, or pumps. In this review, we discuss the most recent developments in this technology with particular attention to the potential benefits and outstanding challenges for applications in chemistry, biology, and medicine.     

Raman reporter-coated gold nanorods and their applications in multimodal optical imaging of cancer cells

We report the preparation of a kind of surface-enhanced Raman scattering (SERS) tags and explore their applications in multifunctional optical imaging of cancer cells. The proposed nanoparticles (SERS tags) are prepared by connecting dye molecules directly onto the surfaces of gold nanorods through Au–S or Au–N interactions. The dye molecules are used as Raman reporters, while gold nanorods are used as enhanced materials due to their localized surface plasmon resonance effect. Multilayered polymers are further coated onto the surfaces of the nanoparticles to reach better stability and biocompatibility. Gold nanorods with different aspect ratios and different dye molecules conjugated are compared in order to achieve the diversity of SERS tags and find out the optimized condition of SERS tags with the highest signal intensity. Our experiments show that the resulting nanoparticles, which are uptaken by cancer cells, can provide not only dark field cells images but also multiplexing SERS images.