Enhanced Anticancer Property of Polyphenol-Assisted Biogenic
AuNPs/RGO Nanocomposites in Triple-Negative Breast Cancer Cells

The bio-inspired nanocomposites developed from reduced graphene oxide (RGO) and gold nanoparticles
(AuNPs) might be of great significance due to their exceptional physico-chemical properties. In the
present work, the AuNPs/RGO nanocomposites were prepared by a green-synthesis approach using
grape seed proanthocyanidin (GSP), which acts as a natural reducing and stabilizing agent. The
simultaneous biosynthesis of RGO nanosheets from graphene oxide (GO) and AuNPs from chloroauric
acid ions by GSP leads to the development of AuNPs/RGO nanocomposites, which were further
confirmed by various analytical techniques. The analyses of the observed outcomes confirm the removal
of oxygen containing moieties during the transformation process of GO to RGO. Further, AuNPs
were decorated orderly on both sides of the RGO nanosheet surface with an average particle size of
~ 35 nm. The MTT-based cytotoxicity assay revealed the enhanced anticancer activity of the prepared
AuNPs/RGO nanocomposites (IC50 = 15.6 μg/mL) against triple-negative breast cancer cells when
compared to either AuNPs or RGO treatment alone. Moreover, enhanced ROS levels and subsequent
alteration in mitochondrial membrane potential (Δψm) with nuclear fragmentation and apoptotic
features were observed in AuNPs/RGO nanocomposites treated cells. This could be due to the synergistic
effect of AuNPs/RGO in the triple-negative breast cancer cells.