Chiral Plasmonic Hydrogen Sensors

TL;DR

This paper presents a novel chiral plasmonic hydrogen sensor using palladium-based nanohelices with enhanced sensitivity and linearity, suitable for safe, remote hydrogen detection.

Contribution

Introduction of a chiral plasmonic hydrogen sensor based on palladium nanohelices with improved linearity and reduced hysteresis through gold hybridization.

Findings

Strong circular dichroism observed experimentally and theoretically.

Hydrogen uptake alters chiroptical properties proportionally to concentration.

Gold addition reduces hysteresis and improves linearity.

Abstract

In this article, a chiral plasmonic hydrogen-sensing platform using palladium-based nanohelices is demonstrated. Such 3D chiral nanostructures fabricated by nanoglancing angle deposition exhibit strong circular dichroism both experimentally and theoretically. The chiroptical properties of the palladium nanohelices are altered upon hydrogen uptake and sensitively depend on the hydrogen concentration. Such properties are well suited for remote and spark-free hydrogen sensing in the flammable range. Hysteresis is reduced, when an increasing amount of gold is utilized in the palladium-gold hybrid helices. As a result, the linearity of the circular dichroism in response to hydrogen is significantly improved. The chiral plasmonic sensor scheme is of potential interest for hydrogen-sensing applications, where good linearity and high sensitivity are required.