Shu Lei, Zhou Jun, Yuan Xiaocong, Petti Lucia, Chen Jinping, Jia Zhenhong, Mormile Pasquale
Institute of Photonics, Faculty of Science, Ningbo University, Ningbo 315211, China.
Institute of Photonics, Faculty of Science, Ningbo University, Ningbo 315211, China.
Talanta. 2014 Jun;123:161-8. doi: 10.1016/j.talanta.2014.02.015. Epub 2014 Feb 14.
A super-high-sensitivity immunoassay based on surface-enhanced Raman scattering (SERS) was implemented using the nano-Au immune probes and nano-Ag immune substrate. Ultraviolet-visible extinction spectra, transmission electron microscopy (TEM) and scanning electron microscopy (SEM) images, and SERS spectra were used to characterise the nano-Au immune probes and the nano-Ag immune substrate. The nano-Ag immune substrate was prepared by the in situ growth of Ag nanoparticles and the subsequent linkage of these nanoparticles with anti-apolipoprotein B on a silicon wafer. The nano-Ag immune substrate exhibited strong SERS activity, excellent reproducibility, and high biospecificity. The nano-Au immune probes were prepared by immobilising 4-mercaptobenzoic acid (4MBA) molecules as a Raman reporter and anti-apolipoprotein B onto the surfaces of Au nanoparticles. It was found that 4MBA induced the aggregation of Au nanoparticles, resulting in the generation of vast hot spots. Moreover, the nano-Au immune probes exhibited strong SERS activity and high biospecificity. A sandwich-type immunoassay structure consisting of the nano-Au immune probes and nano-Ag immune substrate was used to detect the concentration of apolipoprotein B, where the detection limit was as low as 2 fg/mL (3.878×10(-18) mol/L). Taken together, the experimental results indicate that the proposed immunoassay protocol has a great potential application in biological sensing and clinical diagnostics.
基于表面增强拉曼散射（SERS）的超高灵敏度免疫分析方法采用纳米金免疫探针和纳米银免疫底物来实现。利用紫外可见消光光谱、透射电子显微镜（TEM）和扫描电子显微镜（SEM）图像以及SERS光谱对纳米金免疫探针和纳米银免疫底物进行表征。纳米银免疫底物通过在硅片上原位生长银纳米颗粒并随后将这些纳米颗粒与抗载脂蛋白B连接来制备。纳米银免疫底物表现出很强的SERS活性、出色的重现性和高生物特异性。纳米金免疫探针通过将作为拉曼报告分子的4-巯基苯甲酸（4MBA）分子和抗载脂蛋白B固定在金纳米颗粒表面来制备。发现4MBA诱导金纳米颗粒聚集，从而产生大量热点。此外，纳米金免疫探针表现出很强的SERS活性和高生物特异性。由纳米金免疫探针和纳米银免疫底物组成的夹心型免疫分析结构用于检测载脂蛋白B的浓度，其检测限低至2 fg/mL（3.878×10(-18) mol/L）。综上所述，实验结果表明所提出的免疫分析方案在生物传感和临床诊断方面具有巨大的潜在应用价值。
