【作者】 刘湘江；

【导师】 俞汝勤； 宦双燕；

【作者基本信息】 湖南大学 ， 分析化学， 2008， 硕士

【摘要】 表面增强拉曼散射技术是一种强有力的分析手段,它已广泛地应用于表面科学、电化学、生物学和材料学。但无论是从事何种相关SERS的研究,如SERS机理方面、基于SERS的化学生物传感器的构建等,制备SERS活性基底或SERS探针都是实验关键步骤。因此,本论文从制备高性能的SERS探针以及基底等关键问题入手,针对其制备过程中的难点,研制了高性能的SERS探针和基底,并利用这些SERS活性基底制成生物探针,进行了一些生物分析。在本文第二章,我们提出了一种制备具有二氧化硅外壳的核壳型SERS探针的新型合成方法。这种合成方法与其他方法相比,制备时间极短,且不需要偶联剂。制备出的SERS探针具有很强SERS信号,且能在各种浓盐溶液和有机溶剂中保持稳定,具有很强抗干扰能力。在第三章中,我们设计了一种简单快速的基底合成方法,制备了一种二维有序SERS活性基底。本章首先考察金溶胶粒径对基底SERS增强因子的影响,然后从基底表面信号的重現性和基底稳定性两个方面评估基底的性能,发现各项指标均优于传统的纳米Ag胶体SERS基底,该基底有作为化学生物检测平台的潜力。在最后一章中,我们利用上述制备的SERS活性基底,开发了一种新型检测人IgG的表面增强拉曼免疫分析（SERIA）方法。此方法优点突出,上述基底的使用,提高了检测灵敏度和重现性。实验结果表明,此方法的检测下限可达8ng·mL^-1,且具有较宽的线性范围(1.0×10^-8-1.0×10^-4 g·mL^-1)。更多还原

【Abstract】 Surface-enhanced Raman scattering （SERS） holds vast potential as a highly sensitive and selective tool for the identification of biological or chemical analytes. Its narrow, well-resolved bands allow simultaneous detection of multiple analytes, and the low intensity of SERS signal of water simplifies investigation of biological samples. The most critical aspect of performing a SERS experiment is the choice and/or fabrication of the noble-metal substrates or SERS probes. This dissertation describes the novel synthesis methods of SERS-active substrates and SERS probe, and their applications in immunoassays. The details are summarized as follows:1. An improved synthesis method of Au@SiO₂ SERS probe has been described in chapter one. The common properties of the core-shell nanoparticle-based SERS tags including Au@SiO2 are the strong SERS signal and extraordinary stability. The most exciting advantage of the method is its simplisty and time saving procedure as compared to other preparing methods reported before. Besides, the proposed methodology eliminates the use of vitrophilic pretreatment during the preparation, which is necessary in other proposed methodologies.2. In chapter two, a novel method of preparing SERS-active substrates with high sensitivity and reproducibility has been stated. Preparation of SERS substrate is always the core procedure in the surface-enhanced Raman scattering experiments. An ideally SERS substrate should generate significantly large with almost equal enhancement factor. The recent nanoparticle array studies show that the precise control of gaps in the sub-10 nm regime, known as“hot spots”, is crucial for fabrication of substrate with uniformly high SERS activity for collective surface plasmons existing inside the gaps. According the discovery of Halas’s research group, we managed to prepare convenient and cost-effective substrate–gold nanosphere arrays with sub-10 nm gaps to obtain high, stable and reproducible SERS signal, which enables trace-level quantitative analysis.3. In chapter three, based on the SERS-active substrate described above, we attempt to develop a novel sandwich-type immunoassay method to detect human IgG. It involves the immobilization of capture antibodies on the surface of microwell plate, the use of the immobilized antibodies to capture antigens from solution, and the indirect measurement of SERS signal of CVs that encapsulated by antibody-modified liposome. The use of substrate of gold nanosphere arrays with sub-10-nm gaps for CV SERS signal recording substantially improved the sensitivity and reproducibility as compared to conventional Ag-colloid substrates. Linear response has been obtained covering the logarithm of concentrations from 1.0×10^-8 to 1.0×10^-4g·mL^-1 with a detection limit of～8ng·mL^-1. The method holds potential applications in detection of various antigens or other clinically important entities.更多还原