In this study, the synthesis, characterization, density
functional
theory calculations (DFT), and effect of polyethylenimine (PEI)-functionalized
nitrogen-doped graphene quantum dots (PEI N-GQDs) and their palladium
metal nanoparticles nanocomposites (PdNPs/PEI N-GQDs) on cancer cells
were extensively investigated. The focus also includes investigating
their cytotoxic and apoptotic effects on ovarian cancer cells, which
pose a serious risk to women’s health and have high death rates
from delayed diagnosis, inadequate response to treatment, and decreased
survival. Graphene quantum dots and their palladium nanocomposites
were differentially effective against ovarian cancer cell lines. In
particular, the smaller particle size and morphology of PdNPs/PEI
N-GQDs nanocomposites compared with PEI N-GQDs probably enhance their
activity through highly improved uptake by cells. These findings emphasize
the importance of particle size in composite drugs for efficient cancer
treatment. DFT results revealed that the Pd-containing nanocomposite,
with a smaller highest occupied molecular orbital–lowest unoccupied
molecular orbital gap, exhibited higher reactivity and anticancer
effects in human ovarian cancer cell line, OVCAR-3. Significantly,
the application of nanocomposites to ovarian cancer cells initiated
apoptosis, offering valuable insights into the intricate interplay
between nanomaterials and cancer biology.