Solution-Processed Large-Area Gold Nanocheckerboard Metasurfaces on Flexible Plastics for Plasmonic Biomolecular Sensing

Abstract

A versatile, solution-processed fabrication strategy combining interference lithography, electroplating, and imprint transfer is developed to realize plastic plasmonic metasurfaces for biomolecular sensing applications. This process is potentially suitable for high-throughput, large-volume, and low-cost production of plasmonic metasurfaces. Gold nanocheckerboard metasurfaces are fabricated using this method and show enhanced performance in plasmonic refractometric sensing applications compared to other localized surface plasmon resonance (LSPR) sensors. An excellent refractive index sensitivity of 435.1 nm RIU-1 and a figure of merit (FoM) of 7.38 are demonstrated for the prototype plasmonic sensors at wavelengths of 570-610 nm. The spectral regions used in sensing are located within the operating wavelength of silicon photodiodes, which allows low analytical instrumentation cost. A plasmonic biosensor is also constructed on the metasurfaces by monitoring the LSPR peak shift that occurs upon high-affinity biomolecular interactions between bovine serum albumin (BSA) and anti-BSA proteins. Moreover, excellent mechanical stability against repeated bending is demonstrated for the plasmonic sensor, which is essential for wearable sensing devices.