基于表面拉曼光谱的光纤生化传感技术研究

发布时间：2018-04-18 16:12

本文选题：表面增强拉曼散射 + 生化监测　；参考：《中北大学》2017年硕士论文

【摘要】：近年来,生化恐怖袭击活动在全球呈蔓延趋势,食品中毒事件也是频繁发生,而这些都是有毒有害的生化分子造成的,因此寻找准确、快捷、指标定量的有害生化分子的检测方法意义重大。现有的光谱学检测手段主要有两种:质谱法和光谱法。表面拉曼增强散射(Surface Enhanced Raman Scattering,SERS)传感技术具有灵敏度高、选择性好、可快速检测的优点,且具有分子结构指纹的功能,因此SERS传感技术在光化学传感器件领域展现出了极大的应用潜力。传统的SERS技术需要在玻璃片上单独地制作金属微纳结构基底,并且必须在大型拉曼光谱仪下面进行检测,检测设备体积大、价格昂贵,不能适应现场检测的需要。光纤具有低损耗、抗干扰、制作成本低、制造简单等优点,通过将贵金属微/纳结构沉积在光纤的端面和表面制备的光纤SERS探针,在保持灵敏度下降不大、快速检测特点的同时,还能够实现对生化样品分子的在线监测和远程检测,因此极大地挑战了传统SERS技术的地位。本论文将光纤SERS探针上的光学理论与技术、现代MEMS/NEMS技术以及食品安全检测迫切需求相结合,提出开展基于SERS效应的光纤探针生化传感技术研究,深入研究了光纤探针设计方法和制备工艺,并制备出两种灵敏度高、稳定性好的光纤SERS探针。利用制备的光纤SERS探针,成功实现了对罗丹明6G(R6G)分子的检测。本文首先介绍了表面增强拉曼散射的基本概念,探讨了光纤生化传感器的基本工作原理及其应用领域。之后针对传统SERS技术的问题设计了一种锥柱组合型光纤SERS探针,基于光线追迹法优化了锥柱组合型光纤SERS探针的结构参数,在以上工作基础上,着重开展了对锥柱组合型光纤SERS探针制备工艺的研究,并成功实现了基于管腐蚀法锥柱组合型光纤SERS探针的批量制备。在此基础上,论文进一步研究了不同光纤探针锥柱区直径和银纳米颗粒修饰时间对光纤SERS探针检测性能的影响,建立了快速、高效、具有指纹识别检测的锥柱组合型光纤SERS传感器,实现了对R6G分子的快速痕量检测,该类型光纤SERS传感器的检测限达到了10-14 mol/L。论文随后针对光纤端面SERS探针的远端检测能力不足的问题,开展了一种基于球形端面结构的光纤SERS探针传感技术研究,包括球型探针结构设计和几何参数优化、SERS探针表面纳米颗粒表征等关键技术研究,开发了基于熔融法和银溶胶自组装法制备光纤球形SERS探针的制备工艺,成功制备出SERS探针敏感结构。利用该SERS探针球型端面表面积大的优点,以R6G作为待测目的物,研究了不同直径端面小球的SERS探针远端检测生化分子的性能,实现了对R6G分子的指纹识别检测。相比于锥柱组合型光纤SERS探针,该探针制备简单安全,稳定性也得到了进一步的提升,验证了本文提出的利用光纤SERS探针传感器对生化目的物进行远端在线快速痕量识别的功能。
[Abstract]:In recent years, chemical and biological terrorist attacks have spread all over the world, and food poisoning incidents have occurred frequently, and these are caused by toxic and harmful biological and chemical molecules, so it is accurate and quick to look for them.It is of great significance to detect harmful biochemical molecules with quantitative index.There are two main methods of spectroscopic detection: mass spectrometry and spectral method.Surface Enhanced Raman scattering (SERS) sensing technology has the advantages of high sensitivity, good selectivity, rapid detection, and the function of molecular structure fingerprint.Therefore, SERS sensing technology has shown great application potential in the field of photochemical sensing devices.The traditional SERS technology needs to fabricate the metal micro-nano structure substrate on the glass and must be detected under the large Raman spectrometer. The detection equipment is large and expensive and can not meet the needs of the field detection.Optical fiber has the advantages of low loss, anti-interference, low cost and simple fabrication. By depositing the noble metal micro / nano structure on the end surface and surface of fiber, the sensitivity of optical fiber SERS probe is not much decreased.At the same time, it can also realize the on-line monitoring and remote detection of biochemical sample molecules, which greatly challenges the status of traditional SERS technology.In this paper, the optical theory and technology of optical fiber SERS probe, modern MEMS/NEMS technology and the urgent need of food safety detection are combined, and the research on biochemical sensing technology of fiber optic probe based on SERS effect is put forward.The design method and fabrication process of optical fiber probe were studied in detail, and two kinds of optical fiber SERS probes with high sensitivity and good stability were prepared.The detection of Rhodamine 6GN R 6G was successfully achieved by using the optical fiber SERS probe.In this paper, the basic concept of surface-enhanced Raman scattering is introduced, and the basic working principle and application field of fiber optic biochemical sensor are discussed.Then, a cone-column composite fiber SERS probe is designed to solve the problem of traditional SERS technology. Based on the ray tracing method, the structural parameters of the cone-column composite fiber SERS probe are optimized.The fabrication process of cone-column composite fiber SERS probe was studied, and the batch fabrication of cone-column composite fiber SERS probe based on tube corrosion method was successfully realized.On this basis, the influence of the diameter of the cone column and the modification time of silver nanoparticles on the detection performance of the fiber SERS probe is further studied, and a fast and efficient method is established.The rapid trace detection of R6G molecule is achieved by using a cone-column combined fiber SERS sensor with fingerprint identification. The detection limit of this type of optical fiber SERS sensor is 10-14 mol / L ~ (-1) 路L ~ (-1) 路L ~ (-1) 路L ~ (-1) ~ (-1).Then, aiming at the problem that the detection ability of optical fiber end SERS probe is insufficient, a kind of optical fiber SERS probe sensing technology based on spherical end structure is studied.The structure design of spherical probe and the characterization of surface nanoparticles of spherical probe were studied. The fabrication process of spherical SERS probe based on melting method and silver sol self-assembly method was developed.The sensitive structure of SERS probe was successfully prepared.Taking advantage of the large surface area of the spherical end surface of the SERS probe, using R6G as the object to be tested, the performance of the SERS probe with different diameters for detecting biochemical molecules at the far end of the probe was studied, and the fingerprint detection of the R6G molecule was realized.Compared with the cone-column composite fiber SERS probe, the preparation of the probe is simple and safe, and the stability of the probe is further improved.The proposed optical fiber SERS probe sensor for remote on-line trace recognition of biochemical targets is verified.
【学位授予单位】：中北大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP212

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