Graphene-Oxide-Coated CuO Nanoparticles for Functionalization of Acetylsalicylic Acid and Diclofenac

A single-step ultrasonic method (20 kHz, 18 W/cm2) 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–graphene-oxide-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.