A simple route to layer-by-layer assembled few layered graphene oxide nanosheets: Optical, dielectric and antibacterial aspects

Thin film is a subject of great interest for energy and environmental applications. Graphene oxide (GO) in this regard can play a vital role in thin film technology because of its extraordinary optoelectronics and environmentally friendly characteristics. Despite the fast development in the GO based material, there are very few reports on optoelectronics and antibacterial activity of GO thin films. Herein, GO thin films of different concentrations have been deposited on glass substrate by spin coating technique. The optical and dielectric properties of GO thin films were determined by the UV-visible technique. Crystalline nature, grain sizes, dislocation density, and lattice strain were examined through X-ray diffraction. The possible change in the π-π* and n-π* electronic transition and the band gap evaluations of GO thin films were also calculated. Raman spectroscopy was applied to check the quality and defects linked to sp2 breathing modes of GO thin films. Surface chemical state and ratio of CC, CO, OCOH, OC, and (O)O were investigated through X-rays photoelectron spectroscopy. GO thin films were also subjected for antibacterial activity tests towards Bacillus cereus and Serratia marcescens and significantly inhibition of bacterial growth in both solid and liquid media was observed. The results emphasise the potential uses of GO thin films in optoelectronics, environmental, and medical device coating for protection against various infectious agents.