Revolutionizing Drug Removal: Green Magnetic Nanoparticles Functionalized with Hydrophobic Deep Eutectic Solvents for Anti-Inflammatory Drug Adsorption

Abstract

Non-steroidal anti-inflammatory medications are popular pharmaceutical and personal products due to their anti-inflammatory properties and ease of availability. However, the complex structure of these pollutants and their existence at low concentration makes them difficult to trace, posing a major challenge in their removal from aquatic environments. Therefore, the disposal and treatment of these emerging compounds have become a key concern in water treatment. In this study, new hydrophobic deep eutectic solvents (HDES) were successfully prepared using a cheap and simple component consist of decanoic acid and 2-pentanol as the hydrogen bond acceptor and hydrogen bond donor, respectively. The prepared HDES was functionalized onto magnetic nanoparticles, namely Fe3O4@HDES, as an efficient adsorbent for diclofenac and ibuprofen. Based on the findings of the cytocompatibility study, HDES offers new possibilities for safe distribution and application. The optimum adsorption conditions, including solution pH, adsorbent amount, and sample volume, were determined using the Taguchi experimental design. The One-Variable-at-a-Time (OVAT) method was used to determine the other parameters, such as the types of adsorbents, contact time, initial concentration, and initial temperature. Analysis of Variance (ANOVA) revealed that the solution pH played the most significant role in the adsorption of both diclofenac and ibuprofen, followed by the adsorbent amount and sample volume. The characterization involved several tools, including Fourier transform-infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), vibrating-sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET) analysis. Both diclofenac and ibuprofen adsorption followed chemisorption, and the process was feasible, spontaneous, and exothermic. Molecular docking also supported the choice of HDES as a functionalized agent by suggesting a schematic diagram of the energetically advantageous adsorption mechanism, which was in good accord with the experimental findings. The interaction between the adsorbent and adsorbates via hydrophobic interaction and hydrogen bonding was found to be accountable for adsorption. The results indicated that green synthesized Fe3O4@HDES offers a possible sustainable and green benefit through the adsorption of diclofenac and ibuprofen from contaminated water as an adsorbent.