Hu Chongya, Shen Jianlei, Yan Juan, Zhong Jian, Qin Weiwei, Liu Rui, Aldalbahi Ali, Zuo Xiaolei, Song Shiping, Fan Chunhai, He Dannong
School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
Division of Physical Biology & Bioimaging Center, Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China.
Nanoscale. 2016 Jan 28;8(4):2090-6. doi: 10.1039/c5nr06919j.
Cellular imaging technologies employing metallic surface-enhanced Raman scattering (SERS) tags have gained much interest toward clinical diagnostics, but they are still suffering from poor controlled distribution of hot spots and reproducibility of SERS signals. Here, we report the fabrication and characterization of high narrow nanogap-containing Au@Au core-shell SERS nanoparticles (GCNPs) for the identification and imaging of proteins overexpressed on the surface of cancer cells. First, plasmonic nanostructures are made of gold nanoparticles (∼15 nm) coated with gold shells, between which a highly narrow and uniform nanogap (∼1.1 nm) is formed owing to polyA anchored on the Au cores. The well controlled distribution of Raman reporter molecules, such as 4,4'-dipyridyl (44DP) and 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB), are readily encoded in the nanogap and can generate strong, reproducible SERS signals. In addition, we have investigated the size-dependent SERS activity of GCNPs and found that with the same laser wavelength, the Raman enhancement discriminated between particle sizes. The maximum Raman enhancement was achieved at a certain threshold of particle size (∼76 nm). High narrow nanogap-containing Au@Au core-shell SERS tags (GCTs) were prepared via the functionalization of hyaluronic acid (HA) on GCNPs, which recognized the CD44 receptor, a tumor-associated surface biomarker. And it was shown that GCTs have a good targeting ability to tumour cells and promising prospects for multiplex biomarker detection.
采用金属表面增强拉曼散射（SERS）标签的细胞成像技术在临床诊断方面备受关注，但它们仍面临热点分布控制不佳和SERS信号重现性差的问题。在此，我们报告了用于识别和成像癌细胞表面过表达蛋白质的含高窄纳米间隙的Au@Au核壳SERS纳米颗粒（GCNPs）的制备与表征。首先，等离子体纳米结构由包覆金壳的金纳米颗粒（约15 nm）制成，由于聚A锚定在金核上，在它们之间形成了高度狭窄且均匀的纳米间隙（约1.1 nm）。拉曼报告分子，如4,4'-联吡啶（44DP）和5,5'-二硫代双（2-硝基苯甲酸）（DTNB），在纳米间隙中易于编码，并能产生强的、可重现的SERS信号。此外，我们研究了GCNPs的尺寸依赖性SERS活性，发现在相同激光波长下，拉曼增强在不同粒径之间存在差异。在一定粒径阈值（约76 nm）下实现了最大拉曼增强。通过在GCNPs上对透明质酸（HA）进行功能化制备了含高窄纳米间隙的Au@Au核壳SERS标签（GCTs），其可识别肿瘤相关表面生物标志物CD44受体。结果表明，GCTs对肿瘤细胞具有良好的靶向能力，在多重生物标志物检测方面具有广阔前景。
