同步辐射红外光谱成像技术对细胞的研究

同步辐射红外显微光谱技术凭借其超高亮度和高空间分辨率的优势,已经在多学科领域中取得了大量的研究成果。特别是在生物医学领域,同步辐射红外显微光谱可以对无染色、无标记的生物样品进行无损检测并可获得生物分子的大量结构信息,因此得到广泛应用。随着同步辐射红外显微光谱技术的发展,生物化学家和光谱学家已经将研究的重点从组织层次的红外光谱成像（组织红外光谱成像）扩展到细胞层次的红外光谱成像（细胞红外光谱成像）,并在近十年的研究中取得了大量的研究成果,但同时也暴露出一些问题,例如（1）细胞或介质中的水在红外光谱酰胺Ⅰ谱带具有很强的吸收;（2）不平整的细胞表面会导致红外光谱中产生Mie散射;（3）细胞红外光谱的复杂性和不确定性会影响数据分析的有效性和准确性。另一方面,生化学家和光谱学家也为解决这些问题采取了许多有用的策略。因此,本综述首先从样品制备、实验设计以及数据分析等方面对最近十年来细胞同步辐射红外光谱成像技术取得的成果进行了总结,随后介绍了目前细胞红外成像技术面临的问题以及解决策略。我们相信,通过多束同步辐射红外光与焦平面阵列（FPA）探测器的结合,同步辐射红外光谱成像技术在对细胞的结构和功能研究中以及其他领域不同材料的研究中都会逐步显示出独特的作用。     

同步辐射红外显微光谱学和成像技术在分析化学中的应用

同步辐射红外显微光谱作为一种新兴的分析技术,一方面利用了红外光谱可以同时表征有机和/或无机、结晶和/或无定形样品的特点,另一方面充分发挥了同步辐射高亮度和高空间分辨率的特性,因此在对小样品或小样品区域的表征上具有传统红外光谱无法比拟的优势。经过20多年的发展,同步辐射红外显微光谱技术已被广泛地应用于多种分析化学领域并取得了丰硕的研究成果。本文总结了最近几年同步辐射红外显微光谱学和成像技术在文化遗产和考古学、地球和空间科学以及化学和高分子科学中的研究和应用进展。     

同步辐射显微红外光谱法应用于杜仲的研究

同步辐射显微红外光谱具有高亮度、高信噪比等优势.应用同步辐射显微红外光谱对于中药进行研究,可以进行微区分析,从而更加深入了解中药的组成.应用同步辐射显微红外光谱对于杜仲的冰冻切片进行研究,采集不同微区的一系列红外光谱;同时对选定区域进行化学成像,进一步研究该区域中化学组成的分布,从而对于杜仲红外光谱中各个峰的归属有深入...     

同步辐射在分子自组装研究中的应用

同步辐射是一种高亮度、高准直性、宽频谱的优质光源,其在物质原子或分子尺度的结构表征方面具有独特的优势。本文介绍了同步辐射在分子自组装研究中的一些应用,主要包括同步辐射X射线散射、时间分辨的小角X射线散射、时间分辨的X射线衍射、X射线精细结构谱,以及红外光谱,详细阐述了同步辐射X射线散射在层状结构、管状结构以及溶液中的组装体结构表征方面的应用。     

细胞功能分子的表面增强拉曼成像及其应用研究进展

表面增强拉曼光谱(surface-enhanced Raman spectroscopy, SERS)具有高灵敏、高通量的特性.基于SERS的拉曼成像技术是一种无损的生物成像技术,已被广泛应用于细胞表面与细胞内生物分子的检测和成像,如对聚糖、microRNA、蛋白质等分子的定量、结构分析与功能追踪等.这一技术也已用于细菌的快速检测、细胞或细菌间的信号通讯研究、细胞p H检测,并可通过活体肿瘤组织的边缘描绘指导手术切除. SERS成像可以规避生命体系中强的分子自荧光以及荧光成像中的光漂白现象,并可以利用不同拉曼信标的指纹光谱实现高灵敏、高通量的生物成像.通过与其他成像技术(如核磁共振成像、光声成像)的结合, SERS成像有望用于更复杂生命体系中生物分子的研究.本文综述了近年来细胞功能分子的表面增强拉曼成像及其应用方面的研究进展.     

荧光相关光谱及其在单分子检测中的应用进展

单分子检测在生命科学、化学、物理学等领域具有重要的意义。荧光相关光谱是单分子检测的新技术,在生命科学领域有巨大的应用潜力。综述了荧光相关光谱单分子检测的原理、实验技术以及在生物分子相互作用、活细胞、核酸、疾病诊断、高通量筛选以及与毛细管电泳联用等领域的研究,并展望了其发展前景。     

激光拉曼光谱(二)

四、在化学上的应用 1.拉曼光谱与红外光谱虽然红外光谱和拉曼光谱均属分子光谱的范畴,研究的对象也大致相同,然而在产生光谱的机理、实验技术、光谱的解析等方面有较大的差别。因此,我们先将两种光谱作一简要的比较。样品的分子吸收红外光源产生红外吸收光谱,对单色光源的散射产生拉曼光谱。吸收光谱和散射光谱都与分子的振动,转动和品格振动等物理过程相关。因此,与红外光谱一样,拉曼光谱也是研究分子(或晶格)振动光谱和分子转动光谱的一种方法。     

红外光谱技术在茶叶分析中的应用综述

在总结大量文献的基础上,对中、近红外光谱技术在茶叶分析中的应用进行了较为全面的综述;指出红外光谱技术因具有速度快、成本低及重现性好等优点,近年来在生物和食品等领域得到了越来越广泛的应用.     

同步辐射及相关核分析技术在纳米材料生物效应研究中的应用

伴随纳米技术的发展,纳米材料的生物效应研究成为热点,然而这一新兴的研究领域对传统的研究方法提出了挑战,其深入研究有赖于方法学的发展。同步辐射是具有高亮度、高准直、宽频谱等优异性质的光源,其在元素分析及物质原子或分子尺度的结构表征方面具有独特的优势。本文介绍了同步辐射及相关核分析技术,主要包括同步辐射X荧光分析、同步辐射X射线吸收光谱(扩展X射线吸收精细结构EXAFS,X射线吸收近边结构XANES)、同步辐射圆二色谱、电感耦合等离子体质谱、中子活化分析、同位素示踪技术等在纳米生物效应研究中的应用,结合本实验室以及国内外的研究工作详细阐述了基于同步辐射以及相关核分析方法应用于纳米材料表征及其在生物体内的定量、分布、结构分析等方面的最新进展。     

无机纳米-生物界面作用的SERS研究

探索生命体对无机纳米材料的生物应答机制是高效、安全、可控地应用无机纳米材料的基础,其关键在于准确理解在生物体系中无机纳米材料与生物分子间的纳米.生物界面作用.本文主要探讨了在纳米-生物界面具有拉曼增强效应的金、银纳米材料;介绍了表面增强拉曼光谱(surface-enhanced raman spectroscopy,SERS)原位研究金、银等无机纳米材料表/界面吸附的核酸、蛋白质、磷脂等生物分子,以及细胞、病毒和细菌等与金、银纳米材料表/界面作用的研究进展;综述了SERS技术在探索纳米-生物界面作用机制、生物分子测定、生物分子界面行为监测中的应用.     

Post-blast detection of traces of explosives by means of Fourier transform infrared spectroscopy

Samples obtained from debris after explosions of about 30 g of energetic materials were analyzed by means of Fourier transform infrared (FTIR) spectroscopy using both, Globar and synchrotron infrared radiation at the ISMI beamline of the Singapore synchrotron light source (SSLS). Low- and high-strength-of-explosion blasts were performed during each test run with the same explosive material. From the spectroscopic measurements, traces of unreacted explosives were found on more than 200 different materials that served as sample catchers in the explosions.The integrality of the experiments done confirmed that FTIR spectroscopy is a sufficiently sensitive method to detect traces of explosives in post-blast residues even of high-strength explosions. The method requires only a minimal amount of sample and enables accurate and very fast identification of the presence of explosive material. Finally, the synchrotron radiation infrared source provided one order of magnitude higher sensitivity compared to the conventional Globar source.     

Post-blast detection of traces of explosives by means of Fourier transform infrared spectroscopy

Samples obtained from debris after explosions of about 30 g of energetic materials were analyzed by means of Fourier transform infrared (FTIR) spectroscopy using both, Globar and synchrotron infrared radiation at the ISMI beamline of the Singapore synchrotron light source (SSLS). Low- and high-strength-of-explosion blasts were performed during each test run with the same explosive material. From the spectroscopic measurements, traces of unreacted explosives were found on more than 200 different materials that served as sample catchers in the explosions.The integrality of the experiments done confirmed that FTIR spectroscopy is a sufficiently sensitive method to detect traces of explosives in post-blast residues even of high-strength explosions. The method requires only a minimal amount of sample and enables accurate and very fast identification of the presence of explosive material. Finally, the synchrotron radiation infrared source provided one order of magnitude higher sensitivity compared to the conventional Globar source.     

Vibrational spectroscopy differentiates between multipotent and pluripotent stem cells

Over the last few years, there has been an increased interest in the study of stem cells in biomedicine for therapeutic use and as a source for healing diseased or injured organs/tissues. More recently, vibrational spectroscopy has been applied to study stem cell differentiation. In this study, we have used both synchrotron based FTIR and Raman microspectroscopies to assess possible differences between human pluripotent (embryonic) and multipotent (adult mesenchymal) stem cells, and how O(2) concentration in cell culture could affect the spectral signatures of these cells. Our work shows that infrared spectroscopy of embryonic (pluripotent) and adult mesenchymal (multipotent) stem cells have different spectral signatures based on the amount of lipids in their cytoplasm (confirmed with cytological staining). Furthermore, O(2) concentration in cell culture causes changes in both the FTIR and Raman spectra of embryonic stem cells. These results show that embryonic stem cells might be more sensitive to O(2) concentration when compared to mesenchymal stem cells. While vibrational spectroscopy could therefore be of potential use in identifying different populations of stem cells further work is required to better understand these differences.     

Infrared spectromicroscopy of biochemistry in functional single cells

Over the years Fourier-Transform Infrared (FTIR) spectroscopy has been widely employed in the structural and functional characterization of biomolecules. The introduction of infrared (IR) microscopes and of synchrotron light sources has created expectations that FTIR could become a generally viable technique to study both structure and reactivity in vivo, inside single cells, by performing measurements that up to a few years ago were the preserve of in vitro experiments on purified macromolecules. In this review we present the state-of-the-art in the application of FTIR spectromicroscopy as a technique for the study of structure and dynamics in single cells, we discuss the performance requirements for this application and review developments in sample handling methods.     

Use of synchrotron-radiation-based FTIR imaging for characterizing changes in cell contents

FTIR imaging of individual cells is still limited by the low signal-to-noise ratio obtained from analysis of such weakly absorbing organic matter when using a Globar IR source. In this study, we used FTIR imaging with a synchrotron radiation source and a focal plane array detector to determine changes in the cellular contents of cryofixed cells after culture for 48 h on Si(3)N(4) substrate. Several spectral differences were observed for cells deprived of glucose compared with control cells: a lower amide I-to-amide II ratio (P < 0.01); a different secondary structure profile of proteins (obtained from amide I spectral region curve fitting), with a significant increase in non-ordered structure components (P < 0.01); and a higher ν(C = C-H)/ν(as)(CH(3)) absorption ratio (P < 0.01), suggesting increased unsaturation of fatty acyl chains. Therefore, our study has shown that FTIR imaging with a synchrotron radiation source enables determination of several spectral changes of individual cells between two experimental conditions, which thus opens the way to cell biology studies with this vibrational spectroscopy technique.     

High-resolution microspectroscopy and sub-nanosecond time-resolved spectroscopy with the synchrotron infrared source

Infrared produced as synchrotron radiation has useful qualities for a number of infrared measurement methods. The most important is the high source brightness, which allows infrared microspectroscopy to be performed on sample regions having a size equal to the wavelength of light (a few microns). The source is also pulsed, enabling time-resolved spectroscopy to be performed without the need for a high-speed infrared detector. This paper reviews the qualities of infrared synchrotron radiation, and shows performance capabilities for microspectroscopy and sub-nanosecond time-resolved spectroscopy. Results from the National Synchrotron Light Source infrared beamlines are presented or reviewed.     

Investigation of biodeteriorated historical textiles by conventional and synchrotron radiation FTIR spectroscopy

We have examined specimens of historical biodeteriorated cellulose textiles using synchrotron radiation and conventional source FTIR spectroscopy. The main aim of our research was to investigate structural changes caused by ageing and biodeterioration in different types of cellulose fibres. We compared the results, obtained with both methods regarding spectral quality and information obtained with each method. Additionally, we obtained mapping images of the cross sections of the investigated specimens using synchrotron FTIR in order to analyze structural changes in cross sections, caused due to biodeterioration.     

大科学装置同步辐射光源在生命分析化学中的应用

大科学装置的建设和水平是一个国家科技发展程度的标志. 同步辐射装置是一种先进的多学科交叉的高端大科学研究设施, 作为独特的宽光谱高亮度光源, 同步辐射光源提供了其他光源所无法比拟的优势. 我国迄今已建成的最大的大科学装置—— 上海光源的建立和应用是新中国成立60年来的重大成就之一, 标志着我国在建设国际先进水平的大型科学实验装置方面具备了高水平的技术和集成与创新的能力, 已进入国际先进行列. 本文侧重介绍同步辐射光源在生命分析化学领域中的巨大作用, 并以上海光源为例介绍同步辐射光源装置的发展和应用状况, 旨在唤起和推动我国分析化学家的高度重视, 并充分利用我国这一先进的大型科学装置, 将生命分析化学的研究推进到一个崭新的、更高的层次.     

Characterization of mannitol in Curvularia protuberata hyphae by FTIR and Raman spectromicroscopy

FTIR and Raman spectromicroscopy were used to characterize the composition of Curvularia protuberata hyphae, and to compare a strain isolated from plants inhabiting geothermal soils with a non-geothermal isolate. Thermal IR source images of hyphae have been acquired with a 64 × 64 element focal plane array detector; single point IR spectra have been obtained with synchrotron source light. In some C. protuberata hyphae, we have discovered the spectral signature of crystalline mannitol, a fungal polyol with complex protective roles. With FTIR-FPA imaging, we have determined that the protein content in cells remains fairly constant throughout the length of a hypha, whereas the mannitol is found at discrete, irregular locations. This is the first direct observation of mannitol in intact fungal hyphae. Since the concentration of mannitol in cells varies with respect to position and is not present in all hyphae, this discovery may be related to habitat adaptation, fungal structure and growth stages.     

Modeling infrared beam lines with Shadow and Zemax

Ray tracing software is an important tool in the design and develop infrared beam lines. It provides layout coordinates, beam shape and size at mirrors, location of foci and performance estimates. Of the software that models reflective optics, a combination of Shadow [1] and Zemax [2] are discussed. Shadow generates light source rays from its accurate model of synchrotron bend magnets to provide realistic ray distributions. The optical path is traced from this source via optical components to a final image. Although Shadow makes the entire ray trace it has limited graphics and export capability that are features of Zemax. The source rays and optical coordinates generated by Shadow can be used by Zemax to position the optics and launch the rays to simulate the actual system. A conversion of the synchrotron source generated in Shadow that Zemax can use is presented.