title: Plasmonic gold mushroom arrays with refractive index sensing figures of merit approaching the theoretical limit.
abstract: Localized surface plasmon resonance (LSPR)-based sensing has found wide applications in medical diagnosis, food safety regulation and environmental monitoring. Compared with commercial propagating surface plasmon resonance (PSPR)-based sensors, LSPR ones are simple, cost-effective and suitable for measuring local refractive index changes. However, the figure of merit (FOM) values of LSPR sensors are generally 1-2 orders of magnitude smaller than those of PSPR ones, preventing the widespread use of LSPR sensors. Here we describe an array of submicrometer gold mushrooms with a FOM reaching ~108, which is comparable to the theoretically predicted upper limit for standard PSPR sensors. Such a high FOM arises from the interference between Wood's anomaly and the LSPRs. We further demonstrate the array as a biosensor for detecting cytochrome c and alpha-fetoprotein, with their detection limits down to 200 pM and 15 ng ml(-1), respectively, suggesting that the array is a promising candidate for label-free biomedical sensing.
authors: 1] State Key Laboratory of Optoelectronic Materials and Technologies, School of Physics and Engineering, Sun Yat-sen University, Guangzhou 510275, China [2].
authors: Yang
authors: Y
authors: Shen
authors: Jianhua
authors: J
authors: Zhou
authors: Tianran
authors: T
authors: Liu
authors: Yuting
authors: Y
authors: Tao
authors: Ruibin
authors: R
authors: Jiang
authors: Mingxuan
authors: M
authors: Liu
authors: Guohui
authors: G
authors: Xiao
authors: Jinhao
authors: J
authors: Zhu
authors: Zhang-Kai
authors: ZK
authors: Zhou
authors: Xuehua
authors: X
authors: Wang
authors: Chongjun
authors: C
authors: Jin
authors: Jianfang
authors: J
authors: Wang
mesh_terms: D015374:Biosensing Techniques; D003198:Computer Simulation; D045304:Cytochromes c / Q000378:metabolism; D004560:Electricity; D006046:Gold / Q000737:chemistry*; D006801:Humans; D012031:Refractometry; D013057:Spectrum Analysis; D020349:Surface Plasmon Resonance; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D000509:alpha-Fetoproteins; D006046:Gold; D045304:Cytochromes c