title: Single protein sensing with asymmetric plasmonic hexamer via Fano resonance enhanced two-photon luminescence.
abstract: Fano resonances in plasmonic systems have been proved to facilitate various sensing applications in the nanoscale. In this work, we propose an experimental scheme to realize a single protein sensing by utilizing its two-photon luminescence enhanced by a plasmonic Fano resonance system. The asymmetric gold hexamer supporting polarization-dependent Fano resonances and plasmonic modes without in-plane rotational symmetry is used as a referenced spatial coordinate for bio-sensing. We demonstrate via the full-vectorial three-dimensional simulation that the moving direction and the spatial location of a protein can be detected via its two-photon luminescence, which benefits from the resonant near-field interaction with the electromagnetic hot-spots. The sensitivity to changes in position of our method is substantially better compared with the conventional linear sensing approach. Our strategy would facilitate the sensing, tracking and imaging of a single biomolecule in deep sub-wavelength scale and with a small optical extinction cross-section.
authors.affiliation: College of Electronic Engineering, South China Agricultural University, Guangzhou, 510642, P.R. China.
authors.forename: Hai-Dong
authors.initials: HD
authors.lastname: Deng
authors.affiliation: College of Electronic Engineering, South China Agricultural University, Guangzhou, 510642, P.R. China.
authors.forename: Xing-Yu
authors.initials: XY
authors.lastname: Chen
authors.affiliation: Department of Electronic Engineering, College of Information Science and Technology, Jinan University, Guangzhou 510632, P.R. China. e_chui@qq.com.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Nonlinear Physics Centre, Australian National University, Acton, ACT 2601, Australia. andrey.miroshnichenko@anu.edu.au.
authors.forename: Andrey E
authors.initials: AE
authors.lastname: Miroshnichenko
mesh_terms: D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D057054:Molecular Imaging / Q000379:methods*; D011506:Proteins / Q000737:chemistry*
chemical_list: D011506:Proteins