A single-step ultrasonic method (20 kHz) is demonstrated for the formation of acetylsalicylic acid-Fe3O4-graphene oxide nanocomposites (∼80 nm) in aqueous solution. The electronic molecular structure of these nanocomposites is stable in acidic or basic aqueous medium. Coating of these nanocomposites with poly­(vinyl alcohol) (PVA) occurs through increased binding with drug, magnetite, Fe­(II)–C–O and carbonaceous network of graphene oxide. PVA-coated-acetylsalicylic acid-Fe3O4-GO nanocomposites substantially improve acetylation of pristine ascorbic acid than free unmodified drug or uncoated acetylsalicylic acid-Fe3O4-GO nanoparticles because of enhanced electron density through the presence of magnetite and graphene oxide, and specific binding of PVA with drug and ascorbic acid.

A single-step ultrasonic method (20 kHz, 18 W/ cm 2 ) is demonstrated for the functionalization of pristine nonsteroidal anti-inflammatory drugs: acetylsalicylic acid and diclofenac with preformed graphene-oxide-coated CuO nanoparticles. These nanoparticles are positively charged and have a flower-like morphology with a mean size of <340 nm consisting of a pure CuO phase. Ultrasound causes complexation of each drug with these nanoparticles, and as a consequence, new advanced pharmaceutical nanocomposites, acetylsalicylic-acid−grapheneoxide-coated CuO and diclofenac−graphene-oxide-coated CuO, are formed. The surface composition and electronic molecular structure of these nanocomposites are modified at pH values from 1 to 8 through the specific interactions involving Cu−O, C−H, and H-bond formation with the carboxylic and carbonyl groups of acetylsalicylic acid, diclofenac, and graphene oxide.

We demonstrate a single-step ultrasonic in situ complexation of salicylic acid during the growth of Fe3O4-reduced graphene oxide nanoparticles (∼10 nm) to improve the antioxidant and antiproliferative effects of pristine drug molecules. These nanoparticles have a precisely defined electronic molecular structure with salicylic acid ligands specifically complexed to Fe­(III)/Fe­(II) sites, four orders of magnitude larger electric surface potential, and enzymatic activity modulated by ascorbic acid molecules. The diminishing efficiency of hydroxyl radicals by Fe3O4-rGO-SA nanoparticles is tenfold higher than that by pristine salicylic acid in the electro-Fenton process. The H+ production of these nanoparticles can be switched by the interaction with ascorbic acid ligands and cause the redox deactivation of iron or enhanced antioxidation, where rGO plays an important role in enhanced charge transfer catalysis. Fe3O4-rGO-SA nanoparticles are nontoxic to erythrocytes, i.e., human peripheral blood mononuclear cells, but surpassingly inhibit the growth of three cancer cell lines, HeLa, HepG2, and HT29, with respect to pristine salicylic acid molecules.