Fabrication of a citrus flavonoid hesperetin-capped gold nanoparticles-reduced graphene oxide nanocomposites (Hes-Au/rGONCs) as a potential therapeutic agent for triple negative breast cancer and bacterial infections

Hesperetin (Hes) is a Citrus Flavonoid, which is confirmed to have extensive therapeutic effects, comprising antimicrobial, antioxidant, anticancer, cardiovascular protection, and so forth. To overcome the poor solubility, here we attempt to synthesize the Hes-mediated gold nanoparticles bio-functionalized in reduced Graphene oxide (Hes-Au/rGONCs) to increase the therapeutic efficacy of Hes. The characterization of synthesized Hes-Au/ rGONCs were analysed using UV-vis spectrophotometry, FT-IR, Raman spectroscopy, X-ray diffraction analysis (XRD), XPS, HPLC, SEM, EDX and HR-TEM. The absence of vibrations at 1516 and 1381 cm-1 shows the involvement of hydroxyl groups of phenols and enols in anchoring Au on the surface of rGO. In XRD, the planes at (111), (200), (220) and (311) revealed the face centered cubic (fcc) crystalline structure of gold nanoparticles that were functionalized on rGO nanosheets. Hes-Au/rGONCs synthesised produced a highly negative zeta potential of-36.44 mV due to their stability. The Hes-rGO/Au-NPs were analysed for their surface morphology by SEM. The HR-TEM micrographs exhibited uniform distribution and homogenous spherical shaped AuNPs with an average size of 21.37 & PLUSMN;5.7 nm on rGO sheets. The bio reduction percentage was calculated as 98.86% by using HPLC. The inhibitory concentration (IC50) of free-Hes and nanocomposites were 157.57 and 38.41 & mu;M, respectively. The Hes-Au/rGONCs possess effective bactericidal activity against gram positive bacterial species than against gram negative bacterial strains. The resazurin dye assay confirms the MIC values of Hes-Au/ rGONCs. Hereby, the outcome of these studies suggested that the fabricated Hes-Au/rGONCs have potential biomedical applications.