Gold-Copper Oxide Core-Shell Plasmonic Nanoparticles

Noble metal nanoparticles exhibit localized surface plasmon resonance (LSPR) when interacting with light. This property has led to the study of these particles for numerous applications, such as catalysis, energy, biosensing, gas detection, and chemical sensing. One commonly used material in hydrogen sensing is palladium, which can dissociate hydrogen gas and form a hydride, resulting in a shift of the LSPR absorption. Core-shell nanoparticles consisting of a noble metal core and a shell material, such as a transition metal oxide, could provide a material system for hydrogen detection with a more permanent plasmonic shift during exposure to hydrogen compared to palladium. In this work, we show the synthesis of various noble metal core-shell nanoparticles, including gold-copper (I) oxide with spherical, rod, spiked, and bipyramid structures and evaluate their plasmonic behavior and ability to detect hydrogen in colloidal suspensions. In addition, we will discuss the plasmonic properties of these particles and hydrogen sensing ability on various substrates, such as metals.