基于NIR-SERS光谱技术分析宫颈癌氧合血红蛋白

采用电解法制备新型、高效纳米银膜作为近红外表面增强拉曼散射(NIR-SERS)基底,检测了22例健康女性和22例宫颈癌患者氧合血红蛋白的NIR-SERS光谱。对比宫颈癌患者与健康女性氧合血红蛋白NIR-SERS光谱,发现两者区别明显。利用多变量统计分析方法得到宫颈癌患者与健康女性氧合血红蛋白的NIR-SERS光谱在472、662、720和1209 cm-1谱峰处区别最为明显,诊断的特异性与灵敏度均为86.4%。由谱峰归属分析得知,宫颈癌患者血液中高铁血红蛋白吡咯环折叠振动、氧合血红蛋白吡咯环的对称变形振动、反对称变形振动和吡咯环间CmH基团的变形振动等振动模式与健康女性相比有明显的减少。研究表明,NIR-SERS技术结合多变量统计分析方法可以较好地区分宫颈癌患者和健康女性氧合血红蛋白,有望发展成为一种新型的宫颈癌临床诊断工具。     

食管癌患者血红蛋白表面增强拉曼散射光谱的统计分析

应用表面增强拉曼散射(SERS)光谱技术,以Ag纳米粒子为基底,对24例食管癌患者及20例健康人的血红蛋白样本进行了检测,并采用主成分分析(PCA)与判别分析方法对检测到的光谱数据进行分析。实验得到食管癌患者与健康人血红蛋白SERS光谱存在的区别反映了两组血红蛋白内部物质的含量差异,结果显示,与健康人相比,食管癌患者的血红蛋白中有更多的亚铁离子处于低自旋态。统计分析方法所得的光谱峰值PC得分的三维散点图对食管癌患者与健康人区别也较明显。本文方法的总准确率为91%,诊断灵敏度为96%,诊断特异性为85%。结果表明,通过血红蛋白SERS光谱的检测和统计分析,可为早期食管癌的诊断提供依据。     

金颗粒为活性基底的裸鼠血清表面增强拉曼散射光谱分析

对肿瘤裸鼠血清进行显微共聚焦拉曼光谱测量,并将血清的普通拉曼光谱与以金纳米颗粒为基底的表面增强拉曼散射(SERS)光谱进行对比,结果表明金纳米粒子作为活性基底对裸鼠血清具有显著的拉曼增强作用,在很多常规拉曼光谱中未能检测出的信息在SERS光谱中得以体现。这源于血清中的物质与金纳米颗粒之间的化学吸附和相互作用,使得微量样品也能够通过SERS光谱来反映出血清中各种蛋白质、脂类、糖类、核酸以及其他成分的分子结构等信息。血清中各种成分的信息可以反映体内各种细胞和组织的生理代谢及病理变化,血清的SERS光谱将为疾病的诊断和治疗提供一种有效手段。     

基于R6G探针表面增强拉曼散射的pH传感

用金纳米粒子(Au NPs)作为基底,基于罗丹明6G(R6G)探针分子拉曼特征峰随pH的变化,构建了一种具有表面增强拉曼散射(SERS)信号输出的pH传感器。由于(闭)开环形式下存在的(去)质子化R6G分子吸附于增强基底表面的倾斜度取向不同,R6G在不同pH下表现出了不同的SERS活性。根据寻找到的R6G在1363 cm-1和1314 cm-1位置处的SERS光谱峰面积比与pH的线性关系,设计出pH传感器。实验结果表明:R6G的SERS信号在室温下可以稳定2 h以上;当样品溶液pH在7和3之间转换时,传感器表现出了较好的恢复性。在pH检测过程中引入其他金属阳离子后,该探针表现出了对H+较好的选择性。通过检测实际样品的pH发现,该探针的分析性能良好,适于在酸性介质中检测pH。     

亚硝酸钠和氧合血红蛋白反应的拉曼光谱

采用显微拉曼光谱技术研究了亚硝酸钠(NANO2)与氧合血红蛋白(HBO2)在水溶液中的相互作用,为检测高铁血红蛋白(MetHb)提供了一种新的方法.激发波长514.5 nm,血红蛋白取自健康成人的血液.结果显示NANO2与氧合血红蛋白反应后,氧合血红蛋白特征峰570 cm-1与水合高铁血红蛋白(MetHbH2O)特征峰495 cm-1强度的比值I570/I494,以及铁离子低自旋念与高自旋态特征峰强度的比值I1386/I1555均减小.对血红蛋白氧化态敏感的特征峰向低波数方向移动,对卟啉环中心孔径大小敏感的峰向高波数方向移动.研究表明拉曼光谱能够监测到NaNO2对血红蛋白的影响,鉴别血红蛋白与水合高铁血红蛋白,可作为一种检测高铁血红蛋白的新方法.     

激光拉曼光谱法无损鉴别三七及其伪品

应用激光拉曼光谱技术准确无损鉴别三七及其伪品菊三七、藤三七和姜黄。采集了三七及其伪品的拉曼光谱图,并结合二阶导数拉曼图谱对其进行定性鉴别。四种药材的图谱中均出现了1330、1040、943、310 cm-1糖类碳水化合物的拉曼特征峰。三七的谱图中出现了1080 cm-1和1120 cm-1皂苷类化合物的拉曼振动峰;菊三七的谱图中出现了820、899、1144、2935 cm-1b-谷甾醇、吡咯里西啶类生物碱及长链脂肪烃的拉曼特征峰;藤三七的谱图中出现了1462 cm-1和1695 cm-1的腺苷类和尿嘧啶类化合物的拉曼振动峰;姜黄的谱图中出现了962、1187、1433、1596、1630 cm-1等姜黄素类化合物的拉曼振动峰。以上专属特征峰的差异可将三七及其伪品进行很好的区分,并据谱图信息可建立四味中药的拉曼指纹图谱。二阶导数拉曼光谱图可以对三七及其伪品的鉴别结果进行进一步补充验证说明。此方法可准确直接、快速鉴别三七及其伪品。     

恶性骨肿瘤患者红细胞的拉曼光谱研究

通过对正常人和恶性骨肿瘤患者红细胞的拉曼光谱进行了研究.发现对于恶性骨肿瘤患者,部分谱线如1001.2,1228.8,1398.7,1372.8cm-1红移了2～4cm-1,说明这些谱线对应的基团内部构象发生微小变化.以1586cm-1为标记峰得到各峰的相对峰强比,发现恶性骨肿瘤患者红细胞的拉曼峰相对于正常人的相对强度的比值在1505,1228,1087,1001和747cm-1处显著减小,说明亚铁血红素、苯丙氨酸和脱氧核糖在红细胞内的含量减少.由统计分析可知Ⅰ1586/1228,Ⅰ1586/1001和Ⅰ1586/1169的峰-峰比的变化可为恶性骨肿瘤的早期诊断提供一定的依据.     

活体糖尿病小鼠中单个白细胞的拉曼光谱分析

利用拉曼光镊并结合多元统计分析方法无损地对活体糖尿病(DM)小鼠中的白细胞(WBC)进行了研究,分别检测了糖尿病和正常小鼠活体中的白细胞拉曼光谱,利用主成分分析(PCA)建立拉曼光谱诊断多元统计算法模型。结果表明,患糖尿病小鼠和正常小鼠白细胞拉曼光谱差别明显,且实验存在较好的重现性。利用PCA统计分析方法得到诊断特异性和灵敏度达到了98%。在活体糖尿病小鼠白细胞中出现较高的蛋白质的特征峰1302cm-1,表明活体糖尿病白细胞中的蛋白质浓度比正常状态高。糖尿病小鼠内的白细胞与正常相比,DNA磷酸骨架基团强度和蛋白质酰胺强度升高,表明DNA双螺旋结构、蛋白质主链和氢键体系发生变化,二级构象改变。     

单个肝癌细胞的拉曼光谱分析研究

本工作利用激光镊子拉曼光谱系统研究了人正常肝细胞株(LO2)和肝癌细胞株(SMMC-7721)的单细胞拉曼光谱,对于每个细胞在不同部位测三个点.实验结果显示:正常细胞和癌细胞的平均拉曼光谱存在显著差异;癌细胞谱线强度整体变弱;正常细胞的1658cm-1处峰和1450cm-1处峰的强度比值为0.63,癌细胞的为0.99;癌细胞的核酸、蛋白质、脂类等重要生物分子在结构或含量上都发生了不同的改变.用PCA主成分对单个细胞的平均拉曼光谱进行分析,结果发现PCA可以正确区分出正常细胞和癌细胞.这些结果表明,激光镊子拉曼光谱是判断正常肝细胞和肝癌细胞的有效方法.     

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...     

Rapid detection of Escherichia coli and Salmonella typhimurium by surface-enhanced Raman scattering

In this paper, the surface-enhanced Raman scattering (SERS) is used as an analytical tool for the detection and identification of pathogenic bacteria of Escherichia coli (E. coli) and Salmonella typhimurium (S. typhimurium). Compared with normal Raman signal, the intensity of SERS signal is greatly enhanced. After processing all SERS data, the obvious differences between the SERS spectra of two species are determined. And applying the chemometric tools of principal component analysis and hierarchical cluster analysis (PCA-HCA), the SERS spectra of two species are distinguished more accurately. The results indicate that SERS analysis can provide a rapid and sensitive method for the detection of pathogenic bacteria.     

High Throughput Blood Analysis Based on Deep Learning Algorithm and Self-Positioning Super-Hydrophobic SERS Platform for Non-Invasive Multi-Disease Screening

Blood analysis is crucial for early cancer screening and improving patient survival rates. However, developing an effective strategy for early cancer detection using high-throughput blood analysis is still challenging. Herein, a novel automatic super-hydrophobic platform is developed together with a deep learning (DL)-based label-free serum and surface-enhanced Raman scattering (SERS), along with an automatic high-throughput Raman spectrometer to build an effective point-of-care diagnosis system. A total of 695 high-quality serum SERS spectra are obtained from 203 healthy volunteers, 77 leukemia M5, 94 hepatitis B virus, and 321 breast cancer patients. Serum SERS signals from the normal (n = 183) and patient (n = 443) groups are used to assess the DL model, which classify them with a maximum accuracy of 100%. Furthermore, when SERS is combined with DL, it exhibits excellent diagnostic accuracy (98.6%) for the external held-out test set, indicating that this method can be used to develop a high throughput, rapid, and label-free tool for screening diseases.     

利用激光散射技术研究乙醇对人血红蛋白的影响

研究了过量饮酒情况下乙醇对血液中血红蛋白（Hb）的粒度及其分子结构的影响,以浓度分别为200、300、400、500和600nag／dl的乙醇体外作用Hb3h,采用动态光散射和激光拉曼散射光谱法对作用后的Hb的粒径和拉曼光谱的变化进行检测分析。结果发现,随着乙醇浓度增加,Hb分子粒径会稍减小,氧合Hb占总蛋白比例增加,...     

Selective,Quantitative, and Multiplexed Surface‐Enhanced Raman Spectroscopy Using Aptamer‐Functionalized Monolithic Plasmonic Nanogrids Derived from Cross‐Point Nano‐Welding

Recent advances in surface‐enhanced Raman spectroscopy (SERS) have resulted in multiplexing with unprecedented levels of sensitivity and selectivity in trace‐amount detection. However, quantification of multiple trace‐amount molecules with ng‐level accuracy has yet to be demonstrated due to nonuniform distribution of SERS enhancement and random adsorption of molecules at low concentrations. While Raman reporter‐free SERS is favorable for quantification in that the unique fingerprint spectra of molecules enable specific molecular identification, it has yet to be demonstrated due to poor reproducibility and insufficient SERS enhancement. Raman reporter‐free multiplex SERS with highly accurate quantification is successfully realized by versatile aptamer‐functionalized plasmonic Au nanogrids with uniform SERS enhancement. By cross‐point nano‐welding, monolithic Au nanogrids with excellent uniformity and high stability in aqueous media are produced. Raman reporter‐free multiplex detection and highly accurate quantification of concentration and composition is realized at picomolar levels. As a demonstration, Au nanogrids functionalized with bisphenol A‐specific aptamers successfully detect and quantify trace‐amounts of bisphenol A (8.49 ng) from thermal receipt paper. Moreover, principal component analysis is applied to multiplex SERS spectra to establish a ternary composition map, which can potentially serve as a practical reference for future Raman reporter‐free SERS.     

金属尖端角度对表面增强拉曼散射的影响

金属尖端对于表面拉曼散射有增强的效果,但尖端的尖锐程度对于表面增强拉曼散射(Surface-Enhanced Raman Scattering, SERS)的影响很少有定量的报道。为了研究角度大小与SERS的关系,需要制备具有不同角度的结构。利用数字微镜设备（Digital Micro mirror Device, DMD）进行光学投影光刻制备了四组样品,分别具有30°60°90°120°角金属微结构,测量了这些结构对应的SERS谱,研究金属尖端角度大小对于SERS的影响。研究发现,锐角具有更好的表面增强拉曼散射效果,而且增强效果对角度依赖强烈,角度越小增强效果越明显;钝角情况下,SERS对于角度大小依赖的敏感度下降。     

头发光谱显微成像数据处理分析方法及其应用

随着多通道探测技术、集成显微技术和计算机及分析技术的发展,红外和拉曼光谱技术及光谱显微成像技术在生物及医学领域得到广泛应用并成为一种向实用化发展的趋势。但是,要从光谱测量中获得准确、有用的信息需要对光谱及成像数据进行细致、合理的分析。本文工作应用MATLAB软件编程,结合单谱线分析和多谱线多变量分析的方法,对健康人和病人头发横截面微观扫描的拉曼光谱数据进行分析,结果表明,通过对头发拉曼光谱细致处理和数据分析可以揭示被检测人之间的差异。这项工作是把拉曼光谱成像技术及相关光谱分析方法应用于生物医学领域的一个实例。     

Supported Faceted Gold Nanoparticles with Tunable Surface Plasmon Resonance for NIR‐SERS

A novel dry plasma methodology for fabricating directly stabilized substrate‐supported gold nanoparticle (NP) ensembles for near infrared surface enhanced Raman scattering (NIR SERS) is presented. This maskless stepwise growth exploits Au‐sulfide seeds by plasma sulfidization of gold nuclei to produce highly faceted Au NPs with a multiple plasmon resonance that can be tuned from the visible to the near infrared, down to 1400 nm. The role of Au sulfidization in modifying the dynamics of Au NPs and of the corresponding plasmon resonance is discussed. The tunability of the plasmon resonance in a broad range is shown and the effectiveness as substrates for NIR SERS is demonstrated. The SERS response is investigated by using different laser sources operating both in the visible and in the NIR. SERS mapping of the SERS enhancement factor is carried out in order to evaluate their effectiveness, stability, and reproducibility as NIR SERS substrates, also in comparison with gold NPs fabricated by conventional sputtering and with the state‐of‐the‐art in the current literature.     

Novel Au–SiO2–WO3 Core–Shell Composite Nanoparticles for Surface‐Enhanced Raman Spectroscopy with Potential Application in Cancer Cell Imaging

With the rapid development of nanotechnology during the last decades, the ability to detect and control individual objects at the nanoscale has enabled us to deal with complex biomedical challenges. In cancer imaging, novel nanoparticles (NPs) offer promising potential to identify single cancer cells and precisely label larger areas of cancer tissues. Herein, a new class of size tunable core–shell composite (Au–SiO₂–WO₃) nanoparticles is reported. These nanoparticles display an easily improvable ≈10³ surface‐enhanced Raman scattering (SERS) enhancement factor with a double Au shell for dried samples over Si wafers and several orders of magnitude for liquid samples. WO₃ core nanoparticles measuring 20–50 nm in diameter are sheathed by an intermediate 10–60 nm silica layer, produced by following the Stöber‐based process and Turkevich method, followed by a 5–20 nm thick Au outer shell. By attaching 4‐mercaptobenzoic acid (4‐MBA) molecules as Raman reporters to the Au, high‐resolution Raman maps that pinpoint the nanoparticles' location are obtained. The preliminary results confirm their advantageous SERS properties for single‐molecule detection, significant cell viability after 24 h and in vitro cell imaging using coherent anti‐stokes Raman scattering. The long‐term objective is to measure SERS nanoparticles in vivo using near‐infrared light.     

柔性表面增强拉曼光谱芯片制备

柔性表面增强拉曼光谱(SERS)基底具有灵活形变的特点,适合不规则曲面的原位检测,甚至可以直接进行擦拭取样的检测。对不同反射率的衬底进行仿真分析和实验测试,可以看到衬底的反射率对拉曼信号的收集有极大的影响。在波长为532 nm的光激发铝箔具有高反射率,因此选择铝箔作为衬底,采用银溶胶滴铸法制备柔性SERS芯片。实验通过控制溶剂成分,利用表面张力梯度引起向内马兰哥尼(Marangoni)流动以抑制咖啡环的产生,可以改善纳米粒子的分布均匀性。拉曼测试结果表明,SERS芯片的增强因子高达1.32×10⁸,对R6G溶液的检测限低至1×10^-11mol,同时芯片表现出良好的信号均匀性。