State Key Laboratory of Chemo/Bio-Sensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University , Changsha 410082, P. R. China.
Anal Chem. 2013 Oct 1;85(19):9213-20. doi: 10.1021/ac4019439. Epub 2013 Sep 17.
We report the development of a novel single-step, multiplexed, homogeneous immunoassay platform for sensitive detection of protein targets based on our realization of high surface-enhanced raman spectroscopy (SERS) signal enhancement by controlled assembly of SERS nanoparticles. An essential design of this platform is the use of gold nanoparticles or nanorods codecorated with specially reduced antibody half-fragments, nonfluorescent Raman-active dyes, and passivating proteins as the SERS nanoparticles. These nanoparticles offer a facile approach to accomplish orientational immobilization of antibodies, minimized interparticle distance, multicolor Raman fingerprint coding, low fluorescence background, as well as excellent biocompatibility and stability. Through sandwiched antibody-antigen interactions, controlled assembly of SERS nanoparticles is realized with a strong SERS signal achieved via plasmonic coupling, creating an immunoassay platform for rapid, sensitive, multiplexed quantification of proteins. This platform is demonstrated for reproducible quantification of three cytokines, interferon gamma, interleukin-2, and tumor necrosis factor alpha, with large signal-to-noise ratio. It is also successfully applied to multiplexed cytokine analysis for T cell secretion studies in complicated biological samples. The developed SERS immunoassay platform may create a simple but valuable tool for facilitating accurate validation and early detection of disease biomarkers as well as for point-of-care tests in clinical diagnostics.
我们报告了一种新颖的基于表面增强拉曼光谱（SERS）信号增强的单步、多重、均相免疫分析平台的开发，用于灵敏检测蛋白质靶标。该平台的一个重要设计是使用金纳米粒子或纳米棒与经过特别还原的抗体半片段、非荧光拉曼活性染料和钝化蛋白共修饰作为 SERS 纳米粒子。这些纳米粒子提供了一种简便的方法来实现抗体的定向固定、最小化粒子间距离、多色拉曼指纹编码、低荧光背景以及优异的生物相容性和稳定性。通过夹心抗体-抗原相互作用，通过等离子体耦合实现 SERS 纳米粒子的可控组装，从而创建了一种用于快速、灵敏、多重蛋白质定量的免疫分析平台。该平台用于可重复定量三种细胞因子，干扰素 γ、白细胞介素-2 和肿瘤坏死因子 α，具有较大的信噪比。它还成功地应用于复杂生物样品中 T 细胞分泌研究的多重细胞因子分析。所开发的 SERS 免疫分析平台可以作为一种简单但有价值的工具，用于促进疾病生物标志物的准确验证和早期检测，以及用于临床诊断中的即时检测。
