Exploring the synergy of radiative coupling and substrate undercut in arrayed gold nanodisks for economical, ultra-sensitive label-free biosensing.

ABSTRACT: We report radiatively coupled arrayed gold nanodisks on invisible substrate (AGNIS) as a cost-effective, high-performance platform for nanoplasmonic biosensing. By substrate undercut, the electric field distribution around the nanodisks has been restored to as if the nanodisks were surrounded by a single medium, thereby provides analyte accessibility to otherwise buried enhanced electric field. The AGNIS substrate has been fabricated by wafer-scale nanosphere lithography without the need for costly lithography. The LSPR blue-shifting behavior synergistically contributed by radiative coupling and substrate undercut have been investigated for the first time, which culminates in a remarkable refractive index sensitivity increase from 207 nm/RIU to 578 nm/RIU. The synergy also improves surface

SUBMITTER: Misbah I 

PROVIDER: S-EPMC8713518 | biostudies-literature | 2021

REPOSITORIES: biostudies-literature