Tailoring the morphological, optical, electrical, and random lasing properties of ZnO nanorods synthesized on metal surfaces for biosensor applications

Laser-based sensors are taking over their counterparts, fluorescence-based sensors, in the field of bioengineering and space communication due to their high amplification, narrow emission beam, low signal-to-noise ratio, and nonlinearity. In this work, we investigated the chemical growth of ZnO nanorods on different metal surfaces (Au, Pt, Ti, and Al) to serve as random laser mediums. Different analytical techniques were used to investigate the optical, electrical, and morphological properties of the fabricated devices. A lasing threshold of 27.68 mJ/cm² with a spectral width of 2.18 nm centered at 385.06 nm is observed when Ti is used as the growth surface. Al surface produces ZnO nanorods with a lasing threshold of 24.21 mJ/cm² and a spectral width of 1.81 nm. Growing ZnO nanorods on metal surfaces using the chemical bath deposition method paves the way for fabricating different random lasing-based biosensors.