Laser reduced graphene oxide-based interdigitated electrode for sensor applications

Abstract

Laser reduced graphene oxide-based interdigitated microelectrodes were functionalized with TiO₂ nanoparticles towards sensor applications. Two kinds of interdigitated microelectrodes were prepared by laser direct writing using graphene oxide (GO) and TiO₂ nanoparticles. One is a TiO₂ nanoparticle-deposited interdigitated microelectrode consisting of GO and laser-induced reduced graphene oxide (rGO), where the rGO/GO/rGO structure was prepared by laser direct writing on a GO-coated PET film and then a TiO₂ sol solution was drop-casted on the electrode. Another is a TiO₂/rGO hybrid interdigitated microelectrode prepared by laser direct writing on a TiO₂ nanoparticle-GO hybrid film. The UV light sensitivity of the TiO₂ nanoparticle-deposited rGO/GO/rGO interdigitated microelectrode and the oxygen quenching behavior were applied to oxygen sensing. The output voltage from the TiO₂ nanoparticle-deposited rGO/GO/rGO structure in the AC detection mode under 369 nm LED irradiation showed clear relationship with the degree of vacuum. The sensing behavior was based on the photo-generated carrier quenching by oxygen. The irradiation of a 405 nm blue violet laser to a TiO₂ nanoparticle-GO hybrid film caused the crystal phase transition from anatase to rutile TiO₂ accompanying the melting of anatase nanoparticles. The TiO₂/rGO hybrid interdigitated microelectrode consisting of anatase TiO₂, rutile TiO₂, and rGO was prepared by laser direct writing. The TiO₂/rGO hybrid interdigitated microelectrode showed the response to visible light irradiation.