激光诱导液面自组装法制备光纤SERS探针及其农药残留检测应用

利用激光诱导液面自组装法制备金纳米棒光纤表面增强拉曼散射(SERS)探针,探讨制备过程中激光诱导功率和诱导时间对探针灵敏度的影响。将优化条件下(70mW,7min)制备的光纤SERS探针与便携式拉曼光谱仪联用,实现福美双、甲基对硫磷两种农药残留的高灵敏度检测,检测灵敏度分别达到10-7 mol/L和5×10-7 mol/L。探针具有良好的SERS检测重复性,相对标准差小于6%。该激光诱导液面自组装法具有操作简单、成本低廉、探针制备时间短等优点,能够实现高灵敏度光纤SERS探针的重复、批量制备;优化制备的光纤SERS探针在多种农药残留检测应用中展现出良好的应用前景。     

基于表面增强拉曼散射的光子晶体光纤传感器

基于表面增强拉曼散射(SERS)的光纤传感器结合了光纤与表面增强拉曼散射效应,具有普通传感器无法比拟的优点.但是,应用普通光纤将带来诸如背景干扰与吸收、光纤自身的荧光效应及拉曼散射等缺点.为解决这一问题,将光子晶体光纤与表面增强拉曼散射效应相结合,称为基于表面增强拉曼散射的光子晶体光纤(PCFs)传感器,具有高灵敏度、...     

微流控拉曼检测芯片的制备与应用

微流控芯片系统具有高效率、低损耗、高安全系数、高灵敏度等优势,表面增强拉曼散射(SERS)光谱具有灵敏度高以及指纹效应强等优点。从两方面对微流控拉曼检测芯片进行综述:微流控芯片通道和SERS基底的制备以及微流控拉曼检测芯片的集成与应用。最后讨论了SERS微流控芯片在便携化应用方面的挑战和机遇,并对整个领域的未来发展方向与前景进行了展望。     

四种多环芳烃的三维荧光谱解析

多环芳烃(PAHs)是普遍关注的优先监测污染物,在水环境中其含量很低,但由于其具有高荧光量子产率,可利用荧光法对其进行检测.运用三维荧光光谱法对网种多环芳烃的荧光光谱进行了解析,较二维荧光光谱能更详细地描述PAHs的性质.实验表明t菲与蒽均有三个较强的荧光区域;芘有多个荧光区域;荧蒽有两个荧光区域.菲、蒽、芘和荧蒽的最大荧光峰分别位于250/364 nm、250/402 nm、240/372 nm及2s6/462 nm.选择最大荧光峰值位置对四种多环芳烃做工作曲线,呈现较好的线性关系.该方法为同时检测水源中多组分痕量PAHs提供了方法基础.     

便携式拉曼光谱仪现状及进展

拉曼光谱仪广泛应用于化学研究、高分子材料、生物医学、药品检测、宝石鉴定等领域,如何进一步小型化、现场化是其未来发展的重要方向。便携式拉曼光谱仪具有体积小、检测方便等特点,为药品检测、环境检测、安检等实时检测领域提供了一种无损快速检测方法。对便携式拉曼光谱仪的组成原理做了简要介绍,并对国内外产业化便携式拉曼光谱仪的现状及技术的进展进行了综述。     

光纤拉曼生化传感器研究进展

光纤拉曼生化传感器是一种基于拉曼散射原理的光纤传感器,它结合了拉曼散射光谱技术和光纤传输的优势,具有体积小、无需标记、高灵敏度和特异性,能够实现实时快速检测的特点,可以广泛应用于生化检测领域低浓度分析物的检测。对光纤拉曼生化传感器的基本原理、结构和工作方式进行相关介绍,以它在食品安全、环境监测和生物医学等多个领域的实际应用为切入点,重点介绍了不同结构光纤拉曼探针的制备过程和对实际分析物的检测限。此外,总结了当前光纤拉曼生物传感器面临的挑战和未来的发展方向,进一步就如何提高光纤拉曼传感器的性能进行了相关讨论。     

在银胶体系中罗丹明B单分子水平上拉曼光谱研究

采用表面增强托曼散射（SERS）技术,比较了单分子水平上银胶纳米体系中罗丹明B（RhB）浓度为10^-11mol／L以下的拉曼光谱和通常单分子水平上罗丹明6G（Rh6G）浓度在10^-11mol／L的拉曼光谱,无论自由沉积在玻璃表面还是在液体环境下的结果显示,单分子水平上Rh B的拉曼光谱灵敏度是Rh 6G的2倍多。因此,利用RhB作为探测试剂将能够提供更加丰富的信息,这对单分子的光谱研究以及高灵敏度探测试剂的应用研究具有重要的意义。     

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。     

基于单传感器补偿融合的农药检测系统设计

针对当前用于农药残留的现场检测仪器存在检测时间长、重复性差及抗温光干扰能力有限等不足,基于酶抑制法结合前置光路补偿及数据融合算法设计了一种稳定、可用于现场检测的便携式农药残留检测系统。该系统主要包括吸光度感知模块和信号数据融合调理模块。吸光度感知模块在样品水浴恒温前提下,增加前置补偿检测光路,降低温度及杂光信号干扰;数据融合调理模块将经光电转化及电路采集的信号分组融合,增强信号真实性。测试表明,该传感器系统具有良好的稳定性与重复性(相对标准偏差小于2.5%),补偿光路的引入有效降低了外界光干扰。经实验证实抑制率高于70%的样品验证率达85%,且抑制率高于50%时不同农药检出浓度均在0.5~5.0 mg/kg范围内,满足现场检测需求。     

大面积图案化电场增强薄膜的设计及制备研究

采用有限时域差分（FDTD）法仿真了不同闪耀光栅结构上的银（Ag）薄膜模型。在633 nm的激发光下，闪耀光栅上周期为1/1200 mm、厚度为15 nm的Ag薄膜模型产生了较强的局域表面等离子体共振（LSPR）效应。利用机械刻划工艺和电子束蒸发镀膜工艺成功制备了这种Ag光栅薄膜，从而大幅降低了图案化电场增强薄膜的制备成本和难度。利用该电场增强Ag薄膜，基于表面增强拉曼散射（SERS），对亚甲基蓝染料进行检测，SERS信号强度增强，与FDTD仿真结果吻合。同时，基底不同位置处的主要特征峰强度的相对标准偏差（RSD）值都小于17%，薄膜表现出良好的均匀性和再现性。     

Research of surface-enhanced Raman scattering on Ag@PMBA@C@Au hybrid nanoparticles

Monodispersed, biocompatible, and readily-functionalized hybrid reporter-embedded core-shell nanopartilces (NPs) have been prepared in a simple route. This composite offers a potential platform for immunochemical detection using surface-enhanced Raman scattering (SERS) due to their high sensitivity, good stability and biocompatiblity. This also provides a new platform for insight into SERS enhancement mechanism.     

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.     

Near‐Infrared SERS Nanoprobes with Plasmonic Au/Ag Hollow‐Shell Assemblies for In Vivo Multiplex Detection

For the effective application of surface‐enhanced Raman scattering (SERS) nanoprobes for in vivo targeting, the tissue transparency of the probe signals should be as high as it can be in order to increase detection sensitivity and signal reproducibility. Here, near‐infrared (NIR)‐sensitive SERS nanoprobes (NIR SERS dots) are demonstrated for in vivo multiplex detection. The NIR SERS dots consist of plasmonic Au/Ag hollow‐shell (HS) assemblies on the surface of silica nanospheres and simple aromatic Raman labels. The diameter of the HS interior is adjusted from 3 to 11 nm by varying the amount of Au³⁺ added, which results in a red‐shift of the plasmonic extinction of the Au/Ag nanoparticles toward the NIR (700–900 nm). The red‐shifted plasmonic extinction of NIR SERS dots causes enhanced SERS signals in the NIR optical window where endogenous tissue absorption coefficients are more than two orders of magnitude lower than those for ultraviolet and visible light. The signals from NIR SERS dots are detectable from 8‐mm deep in animal tissues. Three kinds of NIR SERS dots, which are injected into live animal tissues, produce strong SERS signals from deep tissues without spectral overlap, demonstrating their potential for in vivo multiplex detection of specific target molecules.     

Fabrication of a network structure SERS substrate and the application in ultra-sensitive crystal violet detection

A network structure surface-enhanced Raman scattering(SERS)-active substrate is fabricated by adding Ag sol dropwise on adhesive tape.Scanning electron microscope(SEM) is employed to characterize the structure of the as-prepared substrate.The substrate shows great SERS enhancement ability and good uniformity by using p-aminothiophenol(PATP) as probe molecules.The detection of crystal violet(CV) in aqueous solution is demonstrated,and the detection limit is as low as 10-12M with the aid of the substrate.The results indicate that the proposed method is a potential approach for the fabrication of SERS substrates.     

Surface Plasmon Resonance Sensors Based on Polymer Optical Fiber

Surface Plasmon Resonance （SPR） is a powerful technique for directly sensing in biological studies, chemical detection and environmental pollution monitoring. In this paper, we present polymer optical fiber application in SPR sensors, including wavelength interrogation surface enhanced Raman scattering SPR sensor and surface enhanced Raman scattering （SERS） probe.
Long-period fiber gratings are fabricated on single mode polymer optical fiber （POF） with 120 μm period and 50% duty cycle. The polarization characteristic of this kind of birefringent grating is studied. Theoretical analysis shows it will be advantageous in SPR sensing applications.     

基于表面增强拉曼光谱的结肠癌组织免疫分析

通过表面增强拉曼散射(SERS)标记抗体检测结肠癌组织切片上癌胚抗原(CEA)的表达,探讨SERS标记免疫检测技术用于临床分析结肠癌组织切片中蛋白质表达的可行性。采用种子生长法合成Ag壳Au核复合纳米粒子,将4-巯基苯甲酸(4-MBA)作为标记分子吸附于纳米粒子表面,制备出SERS探针;再将这种探针与CEA单克隆抗体相结合形成SERS免疫探针;最后通过SERS标记的抗体与结肠癌组织切片上相应的抗原发生特异性结合,对滴加探针的组织切片进行SERS检测和成像。结肠癌腺上皮出现很强的SERS信号,而除了少数非特异性吸附产生的信号之外,间质及正常上皮中几乎不出现SERS信号。通过SERS成像可以清晰地看到结肠癌腺上皮显示红色,表明结肠癌腺上皮高表达CEA,而间质及正常上皮几乎显示黑色和深蓝色,只有极个别点为红色,表明间质及正常上皮基本不表达CEA。研究表明,SERS标记抗体检测分析技术具有高灵敏度和高特异性,有望应用于结肠癌组织切片中蛋白质表达的分析,成为结肠癌辅助诊断的一种重要方法。     

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.     

Surface‐Enhanced Raman Scattering Using Microstructured Optical Fiber Substrates

Microstructured optical fibers (MOFs) represent a promising platform technology for fully integrated next generation surface enhanced Raman scattering (SERS) sensors and plasmonic devices. In this paper we demonstrate silver nanoparticle substrates for SERS detection within MOF templates with exceptional temporal and mechanical stability, using organometallic precursors and a high‐pressure chemical deposition technique. These 3D substrates offer significant benefits over conventional planar detection geometries, with the long electromagnetic interaction lengths of the optical guided fiber modes exciting multiple plasmon resonances along the fiber. The large Raman response detected when analyte molecules are infiltrated within the structures can be directly related to the deposition profile of the nanoparticles within the MOFs via electrical characterization.     

Fabrication of a Macroporous Microwell Array for Surface‐Enhanced Raman Scattering

Here, a colloidal templating procedure for generating high‐density arrays of gold macroporous microwells, which act as discrete sites for surface‐enhanced Raman scattering (SERS), is reported. Development of such a novel array with discrete macroporous sites requires multiple fabrication steps. First, selective wet‐chemical etching of the distal face of a coherent optical fiber bundle produces a microwell array. The microwells are then selectively filled with a macroporous structure by electroless template synthesis using self‐assembled nanospheres. The fabricated arrays are structured at both the micrometer and nanometer scale on etched imaging bundles. Confocal Raman microscopy is used to detect a benzenethiol monolayer adsorbed on the macroporous gold and to map the spatial distribution of the SERS signal. The Raman enhancement factor of the modified wells is investigated and an average enhancement factor of 4 × 10⁴ is measured. This demonstrates that such nanostructured wells can enhance the local electromagnetic field and lead to a platform of ordered SERS‐active micrometer‐sized spots defined by the initial shape of the etched optical fibers. Since the fabrication steps keep the initial architecture of the optical fiber bundle, such ordered SERS‐active platforms fabricated onto an imaging waveguide open new applications in remote SERS imaging, plasmonic devices, and integrated electro‐optical sensor arrays.