Quantitative and sensitive detection of alpha fetoprotein in serum by a plasmonic sensor
Xiong Yang,
Hu Huatian,
Zhang Tianzhu,
Xu Yuhao,
Gao Fei,
Chen Wen,
Zheng Guangchao,
Zhang Shunping,
Xu Hongxing
Affiliations
Xiong Yang
The Institute for Advanced Studies, Wuhan University, Wuhan430072, China
Hu Huatian
The Institute for Advanced Studies, Wuhan University, Wuhan430072, China
Zhang Tianzhu
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, Wuhan430072, China
Xu Yuhao
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, Wuhan430072, China
Gao Fei
Physics Teaching and Research Section, Zunyi Medical Univrsity, Zunyi563003, China
Chen Wen
Laboratory of Quantum and Nano-Optics, Ecole Polytechnique Fédérale de Lausanne, LausanneCH-1015, Switzerland
Zheng Guangchao
Key Laboratory of Materials Physics of Ministry of Education, School of Physics and Microelectronics, Zhengzhou University, Zhengzhou450052, China
Zhang Shunping
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, Wuhan430072, China
Xu Hongxing
The Institute for Advanced Studies, Wuhan University, Wuhan430072, China
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.
