College of Science, State Key Laboratory of Agricultural Microbiology, Huazhong Agricultural University, Wuhan, 430070, China.
Analyst. 2012 Mar 7;137(5):1259-64. doi: 10.1039/c2an15997j. Epub 2012 Jan 26.
An immunoassay based on surface enhanced Raman scattering (SERS) spectroscopy was developed to detect muramidase released protein (MRP) antibody against Streptococcus suis II (SS2) utilizing thorny gold nanoparticles (tAuNPs) as SERS substrates. Initially, tAuNPs with multi-branches were prepared by the seed-mediated growth method in the absence of templates and surfactants, facilitating p-mercaptobenzoic acid (pMBA) conjugation covalently onto the tAuNPs through S-Au bonds. The obtained immuno-SERS tag affording strong Raman signals made it possible to establish an application of indirect detection of the MRP antibody against SS2 with a sandwich assay at a highly sensitive level. The Raman intensity at 1588 cm(-1) was proportional to the logarithm of the concentration of MRP antibody in the range of 10 pg mL(-1) to 0.1 μg mL(-1). The detection sensitivity was significantly improved to 0.1 pg mL(-1) by using the immuno-SERS tags. Furthermore, the proposed SERS approach was applied to detect MRP antibody in pig serum samples, and the results agreed well with those of ELISA, indicating great potential for clinical application in diagnostic immunoassays.
基于表面增强拉曼散射（SERS）光谱的免疫分析利用多刺金纳米粒子（tAuNPs）作为 SERS 基底，开发用于检测抗猪链球菌 II（SS2）的 muramidase 释放蛋白（MRP）抗体。首先，通过无模板和表面活性剂的种子介导生长法制备具有多分支的 tAuNPs，通过 S-Au 键将 p-巯基苯甲酸（pMBA）共价接枝到 tAuNPs 上。所获得的免疫 SERS 标签提供了强的拉曼信号，使得可以通过夹心测定法以高灵敏度水平建立对 SS2 的 MRP 抗体的间接检测的应用。在 1588 cm(-1)处的 Raman 强度与 MRP 抗体浓度的对数成正比，范围为 10 pg mL(-1)至 0.1 μg mL(-1)。通过使用免疫 SERS 标签，检测灵敏度显著提高至 0.1 pg mL(-1)。此外，所提出的 SERS 方法用于检测猪血清样品中的 MRP 抗体，结果与 ELISA 的结果吻合良好，表明其在诊断免疫分析中具有很大的临床应用潜力。
