Experimental demonstration of a novel bio-sensing platform via plasmonic band gap formation in gold nano-patch arrays

TL;DR

This paper experimentally demonstrates a new bio-sensing platform using plasmonic band gap shifts in gold nano-patch arrays, showing color change detection for analyte presence with potential applications in biosensing.

Contribution

The study provides experimental validation of a bio-sensing method based on plasmonic band gap shifts in gold nano-patch arrays, including effects of structural imperfections.

Findings

Color variations correlate with analyte deposition.

Surface imperfections influence sensing performance.

Color intensity changes depend on air/filling ratio.

Abstract

We discuss the possibility of implementing a novel bio-sensing platform based on the observation of the shift of the leaky surface plasmon mode that occurs at the edge of the plasmonic band gap of metal gratings when an analyte is deposited on top of the metallic structure. We provide experimental proof of the sensing capabilities of a two-dimensional array of gold nano-patches by observing color variations in the diffracted field when the air overlayer is replaced with a small quantity of Isopropyl Alcohol (IPA). Effects of rounded corners and surface imperfections are also discussed. Finally, we also report proof of changes in color intensities as a function of the air/filling ratio of the structure and discuss their relation with the diffracted spectra.