Simple and low-cost synthesis of Al-doped ZnO/CuO composite nanowires for highly efficient hydration level sensing

In this paper, we report on our investigation of the impact of Al doping on the primary physical properties of SILAR fabricated CuO/ZnO composite nanowires. Our characterization on surface and structural analysis showed that we were able to lightly dope the nanocomposites effectively using the SILAR method, which is cost-effective and repeatable. Conductivity of the Al-doped films changed significantly which resulted in greater sensing response for hydration. We utilized artificial sweat solutions to characterize the sensing response of the films and we demonstrated that sensing response almost doubled with Al doping. Transient response of sweat application also showed that response times were less than 10 s for 2% Al-doping. We conclude that Al doping on CuO/ZnO nanocomposites is an excellent candidate to be utilized for hydration sensing through sweat.