UV induced photocatalytic and antibacterial studies of zinc oxide nanoflowers prepared via casein assisted low-temperature method

Abstract

We report the photocatalytic and antimicrobial properties of zinc oxide nanostructures synthesized using a low-temperature, facile method with the assistance of milk protein, casein. The nanoflower structure with hexagonal-shaped petals was identified in casein assisted zinc oxide, whereas the flower embryo was obtained without casein. The influence of casein in growth mechanism, morphology, and biofunctionalization is also discussed. A noticeable change was observed in the fluorescence spectra of casein added sample. BET analysis reveal that the addition of casein increases the surface area by 60% which implies casein acts as a capping agent during the preparation. In the presence of casein, the larger surface area of the nanostructure provides a greater number of active sites for interaction, allowing for increased photocatalytic activity. The improved antibacterial activity implies the increased diffusing capacity of casein-added zinc oxide through the cell membrane.