▎ 摘　　要

NOVELTY - Green synthesis of reduced graphene oxide nanoparticles, comprises: (a) mixing quantity of carbon source in acid while stirring to obtain solution; (b) adding first oxidant gradually into solution to oxidize carbon source to give suspension; (c) stirring suspension while maintaining temperature of suspension at 35 degrees C; (d) adding Nigella sativa seed extract to suspension while raising temperature of suspension to 60 degrees C; (e) adding hydrogen peroxide to suspension; and (f) isolating resulting reduced graphene oxide nanoparticles by centrifugation. USE - The method is useful for green synthesis of reduced graphene oxide nanoparticles which are useful for inhibiting cancer cell proliferation and microbial activity caused by a microorganism, where the cancer cell includes a breast carcinoma cell or a colon carcinoma cell and the microorganisms are yeast, gram positive and gram negative bacteria. DETAILED DESCRIPTION - Producing reduced graphene oxide nanoparticles for green synthesis of reduced graphene oxide, comprises: (a) mixing a quantity of carbon source in an acid while stirring to obtain a solution; (b) adding a first oxidant gradually into the solution to oxidize the carbon source and obtain a suspension; (c) stirring the suspension while maintaining a temperature of the suspension at 35 degrees C; (d) adding Nigella sativa seed extract to the suspension while raising the temperature of the suspension to 60 degrees C; (e) adding hydrogen peroxide to the suspension; and (f) isolating resulting reduced graphene oxide nanoparticles by centrifugation, where the graphene oxide nanoparticles have a mean diameter of 5-200 nm across the largest dimension and comprises Nigella sativa seed extract.