Anti-cancer and visible-light-driven photocatalyst activities of graphene oxide nanosheets against A549 lung cancer cells and organic dyes

Abstract

The use of graphene oxide (GO) nanosheets (NSs) in cancer cell treatment is a promising and innovative approach to eradicate lung cancer cells and to adsorb and photodegrade organic dyes in water. XRD results revealed that the produced GO NSs have a high crystallinity and a d-spacing value of 0.87 nm. The FTIR spectrum showed that several oxygen-containing functional groups were introduced at the graphite surface from the exfoliation process. The TGA curve result supported the synthesis of GO NSs from the characteristic weight loss behavior. The wrinkled and fold surface morphology of the synthesized GO NSs was confirmed using FE-SEM and TEM. Subsequently, the assessment of their in vitro anti-oxidant and hydroxyl radical scavenging characteristics revealed that the synthesized GO NSs possessed effective antioxidant properties. The viability of A549 lung cancer cells against GO NSs was found to decrease in a dose-dependent manner and their morphology and nuclear damages was assessed by AO/EB and DAPI staining assays. The increased oxidative stress resulted in greater apoptotic cell death, loss of nuclear integrity, and mitochondrial membrane damage against A549 lung cancer cells. The increasing caspase-3 and caspase-9 activation resulted in more apoptotic cell death and cell cycle arrest as determined by flow cytometry. Further, GO NSs demonstrated moderate photocatalytic activity under visible light irradiation, degrading methylene blue (MB) and bromothymol blue (BTB) dye molecules by 44 and 53.5 %, respectively, after 120 min irradiation. Finally, the present study demonstrated that GO NSs possess excellent anti-cancer and moderate photocatalyst activities.