心律失常患者红细胞的光镊拉曼光谱

利用激光光镊拉曼光谱系统,测定健康者红细胞(RBC)和心律失常患者红细胞的拉曼光谱,对健康者红细胞与心律失常患者红细胞的拉曼光谱进行了比较,发现心律失常患者红细胞的部分谱线整体强度有所减弱,部分谱线发生了频移;另外,低强度He-Ne激光对心律失常患者红细胞也存在一定的影响.根据拉曼光谱差异性,进一步探讨其红细胞内容物的...     

基于拉曼光谱技术的精子评筛研究进展

全球成年男性的精子质量呈明显下降趋势。精子质量下降与男性不育虽并非线性关系,但显然与低生育力密切相关。辅助生殖技术针对不育男性精子水平低、形态和运动活力异常等常见问题,通过评估和筛选优质精子,提供了解决男性不育问题的主要技术方案。现有临床研究局限于精子形貌和活力等特征参数的筛选,缺乏针对精子DNA损伤情况的无损评筛手段。本文首先介绍了精子无损评筛技术在辅助生殖领域男科的应用需求以及显微拉曼光谱技术的基本原理,继而对基于拉曼光谱技术的精子研究进行了综述,综合分析探讨了精子的拉曼光谱检测和光谱特征,聚焦精子DNA损伤的拉曼光谱响应问题,最后讨论和展望了精子无损评筛技术的发展前景。     

纳米薄膜基底对表面增强拉曼光谱检测环丙沙星的影响

基于金纳米颗粒薄膜基底和金纳米棒薄膜基底,使用表面增强拉曼光谱（SERS）技术对环丙沙星（CIP）的含量进行了分析检测,为食品中CIP残留检测提供了新方法。通过使用柠檬酸钠还原氯金酸制备金纳米颗粒胶体,以及通过晶种生长法制备金纳米棒胶体,以应用于SERS增强基底。通过不同激发光波长对CIP进行SERS检测,确定了最佳激光波长为780 nm。使用校正集CIP标准溶液,建立CIP浓度-SERS信号强度的工作曲线,使用检验集样本观察工作曲线的预测能力。结果表明：使用金纳米颗粒基底进行CIP的SERS检测,回收率在97.1%～105.0%;使用金纳米棒基底进行SERS检测,回收率在96.3%～121.8%。因此,SERS在检测CIP抗生素领域具有高灵敏度、快速检测等优势。     

拼接光栅型宽波段高分辨率空间外差拉曼光谱仪器 对背向散射拉曼光谱的探测

为了满足微弱背向拉曼光谱信号的高分辨率、宽波段探测,设计并搭建了一台光栅拼接型的宽波段高分辨率空间外差拉曼光谱仪MGSHRS实验平台,对仪器的视场展宽,进行了光谱定标,完成了对拉曼样品的宽波段背向散射拉曼探测.该系统的实际光谱分辨率为3.37 cm~(-1),总的光谱探测范围为5 841 cm~(-1),实验结果证实该技术对于高通量、宽波段、高分辨的拉曼光谱测量展现出极好的应用潜能.     

远程激光拉曼光谱探测系统前置光学系统设计

为实现远程物质高空间分辨力的拉曼光谱探测,设计了共孔径远程激光拉曼光谱探测系统的前置光学系统。光学系统采用共孔径结构,实现了激光发射系统、拉曼光收集系统及微区成像系统的共孔径、共光轴。设计的光学系统能够对激光进行聚焦以缩小激光光斑尺寸,使系统具有优于0.125 mrad的空间分辨率。该拉曼光收集透镜有效通光口径为50 mm,拉曼散射光在耦合透镜焦平面上的像高小于25m,可以与50m狭缝宽度的光谱仪进行空间光耦合,也可使用50m芯径的光纤来耦合光学系统与光谱仪。该系统可用于远距离物质的激光聚焦、拉曼光谱探测及微区成像。     

共振拉曼光谱法检测人体皮肤中类胡萝卜素的研究

类胡萝卜素作为一种强抗氧化剂在人体的抗氧化防御系统中起重要作用。它在人体中的含量可以用来表征人体的健康状况。为了检测人体中的类胡萝卜素,对用共振拉曼光谱法检测人体皮肤中类胡萝卜素进行了实验研究。经过反复实验获得了最佳实验参数。如选择测量部位拇指内侧,入射波长473nm,入射光强度20mW,曝光时间5s。同时通过甘油匹配的方法增加了探测到的拉曼信号的强度。利用拟合差分算法有效去除了荧光背景噪声,获得了明显的人体皮肤中类胡萝卜素的拉曼光谱。     

肺癌组织拉曼光谱的统计分析

使用统计的方法,应用激光显微拉曼光谱法对肺癌变及癌旁正常组织冰冻切片进行了分析研究.结果表明,肺癌组织和癌旁正常组织的拉曼光谱有显著的差异性正常肺组织切片的1392 cm-1附近的C-H变形振动在癌变组织光谱中向高波数移动约6 cm-1;1523 cm-1脂类类胡萝卜素的C=C振动谱带在癌变组织光谱中向高波数移动约3 cm-1;体现在肺癌组织中细胞形态和组织结构发生的变化,说明拉曼光谱法可以用于对良、恶性肺部组织进行鉴别诊断.     

人体组织拉曼光谱研究进展

介绍了拉曼光谱测量技术在人体皮肤、血液、乳腺、胃、肺等组织疾病诊断中的研究概况,同时介绍了拉曼测量新技术的发展概况,展望了它的发展前景.     

Silver Nanoparticle Impregnated Polycarbonate Substrates for Surface Enhanced Raman Spectroscopy

The embedding of nanoscopic metal structures into polymeric matrices represents a convenient way to stabilise a controlled dispersion of protected nanoparticles whilst taking advantage of their physical characteristics. Supercritical carbon dioxide (scCO₂) has been used to produce silver nanoparticles in optically transparent polycarbonate (PC) matrices allowing fine scale dispersions of particles to be produced within a prefabricated polymer component. Characterization of these nanocomposites has been performed using transmission electron microscopy (TEM) and UV‐vis spectroscopy. The substrates give excellent responses in surface‐enhanced Raman spectroscopy (SERS) for both 4‐aminothiophenol and rhodamine 6G target molecules. They offer significant benefits over more conventional SERS substrates in that they are cheap, flexible, mechanically robust and temporally stable. Post‐processing the films via simple etching techniques, provides an additional degree of design control and the potential to fabricate devices with unique excitation and detection geometries for a wide range of applications.     

激光拉曼光谱分析俄歇电子对基因结构的影响

分析俄歇电子辐射对基因结构及成分的影响,探讨其基因损伤的机制.应用激光拉曼散射测定,以放射性碘-125(125 I)标记甲胎蛋白(AFP)基因引物与AFP基因杂交结合辐射后,不同时间内其俄歇电子对基因结构的变化以及对碱基成分的损害程度.结果显示,DNA的骨架构像及碱基的特征振动光谱发生偏移,谱线强度在2～24 h改变较大,而24 h与72 h变化较小.拉曼光谱显示俄歇电子近距离辐照可以引起DNA的磷酸二酯骨架结构损伤,基因中碱基暴露,基团损伤,甚至破坏,基因构像由B型转变为C型特征光谱.结果表明,俄歇电子辐照可改变靶基因骨架结构和构像.损伤或破坏碱基,从而影响靶基因的生物功能.     

On the Combined Application of Raman Spectroscopy and Photoluminescence Spectroscopy for the Diagnostics of Multilayer Heterostructures

Semiconductors - The results of studying GaInAs/GaInP/GaAs photodiode structures grown by metal–organic vapor-phase epitaxy are reported. A procedure for the diagnostics of such multilayer...     

Non-negative Matrix Factorization with Orthogonality Constraints and its Application to Raman Spectroscopy

We introduce non-negative matrix factorization with orthogonality constraints (NMFOC) for detection of a target spectrum in a given set of Raman spectra data. An orthogonality measure is defined and two different orthogonality constraints are imposed on the standard NMF to incorporate prior information into the estimation and hence to facilitate the subsequent detection procedure. Both multiplicative and gradient type update rules have been developed. Experimental results are presented to compare NMFOC with the basic NMF in detection, and to demonstrate its effectiveness in the chemical agent detection problem.     

近红外激光拉曼技术在体探测胃癌腹膜播散

以腹膜接种人胃癌细胞SGC-7901的裸鼠为胃癌腹膜播散的动物模型,进行模拟外科手术,在体探测不同种植期的裸鼠腹膜癌结节及正常腹膜组织的激光拉曼光谱,对比光谱差异,采用支持向量机(SVM)算法对光谱进行分类和分期判决。结果表明,癌结节和正常组织拉曼光谱差异显著,用支持向量机算法进行分类的灵敏度、特异度和诊断准确度分别为95.73%、70.73%和90.73%;不同生长期的癌结节组织拉曼光谱也存在明显差异,用支持向量机算法进行分期的结果分别为98.82%、98.73%和98.78%。从分类结果可以看出,此方法对指导外科手术中癌变组织的识别有重要的意义。     

移频激发差分拉曼光谱仪的多波长光源设计

拉曼光谱检测常常受到荧光的干扰,影响了该技术的推广应用。移频激发差分拉曼光谱方法(SERDS方法)已被证明是一种有效的荧光抑制方法。SERDS实现荧光抑制的关键在于其特殊的激光光源,不仅要求其输出多个相近的波长,而且要求输出的激光功率较高、光谱线宽窄。采用Littrow光栅外腔半导体激光器原理设计实现了一种低成本、便携式的激光光源,可以在15nm的调谐范围内输出多个波长,光谱线宽小于0.2nm,输出功率可达80mW,适合用作移频激发差分拉曼光谱方法的多波长光源,实现拉曼光谱检测中对荧光干扰的抑制。     

High-Density Plasmonic Nanopores for DNA Sensing at Ultra-Low Concentrations by Plasmon-Enhanced Raman Spectroscopy

Solid-state nanopores are implemented in new and promising platforms that are capable of sensing fundamental biomolecular constituents at the single-molecule level. However, several limitations and drawbacks remain. For example, the current strategies based on both electrical and optical sensing suffer from low analyte capture rates and challenging nanofabrication procedures. In addition, their limited discrimination power hinders their application in the detection of complex molecular constructs. In contrast, Raman spectroscopy has recently demonstrated the ability to discriminate both nucleotides and amino acids. Herein, a plasmonic nanoassembly is proposed supporting nanopores at high density, in the order of 100 pores per µm². These findings demonstrate that the device has a high capture rate in the range of a few fm . The pore size is ≈10 nm in diameter and provides an amplification of the electromagnetic field exceeding 10³ in intensity at 785 nm. Owing to these features, single-molecule detection is achieved by means of surface-enhanced Raman scattering from a solution containing 50 fm DNA molecules (≈4.4 kilobase pairs). Notably, the reported spectra show an average number of 2.5 Raman counts per nucleotide. From this perspective, this number is not far from what is necessary to discriminate the DNA sequence.