光子学报, 2018, 47 (12): 1228002, 网络出版: 2019-01-10
基于PS@Ag纳米探针和Si@Ag阵列基底的表面增强拉曼散射特性的肿瘤标志物免疫检测
Surface Enhanced Raman Scattering-based Tumor Immunoassay Using PS@Ag Nano-probes and Si@Ag Array Substrate
表面增强拉曼散射 免疫检测 甲胎蛋白 金字塔结构 Surface-enhanced Raman scattering Immunoassay Alpha fetoprotein Pyramid array
摘要
基于Ag包覆聚苯乙烯球(PS@Ag)纳米探针和Ag覆盖硅金字塔结构(Si@Ag)阵列基底构建“三明治”免疫结构, 开展表面增强拉曼散射(SERS)特性研究, 实现了肝癌肿瘤标志物甲胎蛋白(AFP)的高灵敏、高特异性的检测.通过硝酸银原位还原生成PS@Ag纳米粒子, 再依次链接4-巯基苯甲酸(4-MBA)及甲胎蛋白抗体(Anti-AFP) 制备得到PS@Ag免疫探针.采用Langmiur-Bloggt膜技术、等离子体刻蚀和湿法刻蚀技术, 以PS球阵列为模版, 刻蚀大面积硅金字塔结构, 再依次沉积Ag膜和链接Anti-AFP制备得到免疫基底.结果表明, 基于“三明治”免疫结构的SERS检测方案具有高灵敏度(检测极限为1.75 fg·mL-1)和宽的动态范围(2 fg·mL-1~200 ng·mL-1).此外, 对临床人体血清样品进行SERS免疫检测, 得到了与化学免疫发光法一致的结果, 而且具有更高的灵敏度, 可应用于肝癌的早期检测与诊断.
Abstract
A super-sensitive, high-specific immunoassay of tumor marker based on Surface Enhanced Raman Scattering (SERS) was developed with the sandwich-type immune structure consisted of Ag-covered polystyrene sphere (PS@Ag) probes and Ag-deposited Si pyramid array (Si@Ag) substrate. The PS@Ag immune probe was prepared by successively immobilizing 4-Mercaptobenzoic acid (4-MBA) and Anti-AFP antibodies on the surface of in-situ reduced PS@Ag nanoparticles. The Si pyramid array was fabricated using PS spheres as a template, combining with Langmiur-Bloggt method, reactive ion etching and wet chemical etching techniques. Then, Si @Ag immune substrate was prepared by successively depositing Ag film and immobilizing Anti-AFP antibodies on the surface of Si pyramid array. The results demonstrate that the constructed immunoassay platform exhibits high sensitivity with the limit of detection of 1.75 fg·mL-1 and wide linear range from 2 fg·mL-1 to 200 ng·mL-1. In addition, the detections of serum sample show the SERS-based platform is not only well-consistent with that of chemiluminescent immunoassay but also more sensitive, which could be potentially applied in the practical clinical diagnoses of cancer.
王哲, 洑颢, 梁照恒, 王福艳, 周骏. 基于PS@Ag纳米探针和Si@Ag阵列基底的表面增强拉曼散射特性的肿瘤标志物免疫检测[J]. 光子学报, 2018, 47(12): 1228002. WANG Zhe, FU Hao, LIANG Zhao-heng, WANG Fu-yan, ZHOU Jun. Surface Enhanced Raman Scattering-based Tumor Immunoassay Using PS@Ag Nano-probes and Si@Ag Array Substrate[J]. ACTA PHOTONICA SINICA, 2018, 47(12): 1228002.