Department of Chemistry, Stanford University, 380 Roth Way, Stanford, CA 94305, USA.
Small. 2011 Feb 18;7(4):499-505. doi: 10.1002/smll.201001836. Epub 2011 Jan 3.
Surface-enhanced Raman scattering (SERS) vastly improves signal-to-noise ratios as compared to traditional Raman scattering, making sensitive assays based upon Raman scattering a reality. However, preparation of highly stable SERS-active gold substrates requires complicated and expensive methodologies and instrumentation. Here, a general and completely solution-phase, seed-based approach is introduced, which is capable of producing gold films for SERS applications on a variety of substrates, not requiring surface modification or functionalization. SERS enhancement factors of ≈10(7) were observed. Moreover, solution-phase gold film deposition on highly complex surfaces, such as protein-coated bioassays, is demonstrated for the first time. Protein bioassays coated with such SERS-active gold films are combined with bioconjugated single-walled carbon nanotube Raman labels, affording highly sensitive detection of the cancer biomarker, carcinoembryonic antigen in serum, with a limit of detection of ≈5 fM (1 pg mL(-1) ).
表面增强拉曼散射（SERS）与传统拉曼散射相比，大大提高了信号与噪声的比值，使基于拉曼散射的灵敏分析成为现实。然而，制备高度稳定的 SERS 活性金基底需要复杂且昂贵的方法和仪器。在这里，我们介绍了一种通用的、完全基于溶液相的、基于种子的方法，该方法能够在各种基底上制备用于 SERS 应用的金膜，而不需要表面修饰或功能化。我们观察到 SERS 增强因子约为 10(7)。此外，我们首次证明了在高度复杂的表面（如蛋白质包被的生物测定）上进行溶液相金膜沉积。这种 SERS 活性金膜涂覆的蛋白质生物测定与生物共轭单壁碳纳米管拉曼标记相结合，实现了对血清中癌症标志物癌胚抗原的高灵敏度检测，检测限约为 5 fM（1 pg mL(-1)）。
