Xiong Yang, Hu Huatian, Zhang Tianzhu, Xu Yuhao, Gao Fei, Chen Wen, Zheng Guangchao, Zhang Shunping, Xu Hongxing
The Institute for Advanced Studies, Wuhan University, Wuhan 430072, China.
School of Physics and Technology, Center for Nanoscience and Nanotechnology, and Key Laboratory of Artificial Micro- and Nano-structures of Ministry of Education, Wuhan University, Wuhan 430072, China.
Nanophotonics. 2022 Oct 24;11(21):4821-4829. doi: 10.1515/nanoph-2022-0428. eCollection 2022 Dec.
Quantitative molecular detection based on surface-enhanced Raman spectroscopy (SERS) is still a great challenge because of the highly nonuniform distribution of the SERS hot spots and the nondeterministic spatial and spectral overlap of the analyte with the hot spot. Here, we report a nanoparticle-on-mirror plasmonic sensor excited by surface plasmon polaritons for quantitative SERS detection of alpha fetoprotein in serum with ultrahigh sensitivity. The uniform gaps between the nanoparticles and gold film and the alignment of the gap modes relative to the excitation electric field endow this substrate with a uniform and strong SERS enhancement. The limit of detection reaches 1.45 fM, 697 times higher than that under normal excitation and 7800 times higher than a commercial enzyme-linked immunosorbent assay kit. This approach offers a potential solution to overcome the bottleneck in the field of SERS-based biosensing.
由于表面增强拉曼光谱（SERS）热点分布高度不均匀以及分析物与热点的空间和光谱重叠不确定，基于SERS的定量分子检测仍然是一个巨大挑战。在此，我们报告一种由表面等离激元极化激元激发的镜上纳米粒子等离子体传感器，用于超灵敏定量检测血清中的甲胎蛋白。纳米粒子与金膜之间的均匀间隙以及间隙模式相对于激发电场的排列，赋予该基底均匀且强烈的SERS增强。检测限达到1.45 fM，比正常激发下高697倍，比商业酶联免疫吸附测定试剂盒高7800倍。该方法为克服基于SERS的生物传感领域的瓶颈提供了一种潜在解决方案。
