Green Modified Graphene Oxide Nanoplatelets as Drug Adsorbents

Amino acids and vitamins play crucial roles in pharmaceutical applications, serving as excipients and structural components of drug delivery systems due to their biological diversity and functionality. In this study, to improve the efficiency of drug delivery systems, graphene oxide (GO) nanoplatelets were surface-modified using green chemistry principles with different amino acids (ornithine, proline, leucine, tryptophan, glutamic acid) and one vitamin (nicotinic acid—vitamin B3). The modification processes were conducted at 85°C, and the resulting adsorbent were characterized using DLS, FTIR, and SEM techniques. The drug adsorption capacities of the resulting novel adsorbents were investigated and compared with the adsorption capacity of unmodified GO. In the adsorption studies, fluoxetine hydrochloride (FLX), a selective serotonin reuptake inhibitor (SSRI), was chosen as the model drug, and batch adsorption experiments were performed at varying concentrations. The concentrations of fluoxetine hydrochloride were determined at 226 nm using UV–Visible spectrophotometry. According to the findings, GO nanoplatelets demonstrated a high FLX adsorption capacity of 157 mg/g. Materials modified with amino acids exhibited lower adsorption capacities than GO nanosheets. However, GO nanosheets modified with nicotinic acid (vitamin B3) showed excellent adsorption capacity (252 mg/g) compared to pristine GO, highlighting the effectiveness of the modification. These results indicate that surface modification of GO with amino acids and vitamins has a meaningful impact on drug adsorption performance. This study suggests that biomolecule-based modifications could be a promising approach in the design of graphene oxide-based drug delivery systems.