Thiol-Functionalized Cobalt Ferrite (CoFeO@MPTS) Nanoparticles as Cutting-Edge Adsorbents for Bovine Serum Albumin.

This paper describes the synthesis of CoFe₂O₄ nanoparticles via a simple ultrasonic-assisted co-precipitation method and their functionalization with thiol groups using (3-Mercaptopropyl)trimethoxysilane (MPTS) as the functionalizing agent. The use of ultrasonic energy not only serves as a green energy source but also reduces the reaction time fivefold compared to conventional methods. The synthesized CoFe₂O₄ nanoparticles were characterized for their surface and internal properties using instrumental techniques such as Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and Vibrating Sample Magnetometer (VSM). The functionalized nanoparticles were applied for the effective adsorption of bovine serum albumin (BSA) from a buffered aqueous medium. To enhance the adsorption performance, the influence of pH, amount of solid adsorbent, initial BSA concentration, shaking time, and temperature on protein adsorption was investigated. Lagergren pseudo-second-order adsorption kinetics fitted the BSA adsorption data well, with an acceptable R² value of 0.976. Additionally, the BSA adsorption data were analyzed using Langmuir and Freundlich isotherm models, and it was concluded that the experimental data followed the Langmuir equation more closely than the Freundlich equation. At an initial pH of 5.57 (acetate buffer), the adsorption capacity (Q₀) for BSA protein was found to be 200 mg/g. The thermodynamic study revealed ΔS° and ΔH° values of 17.40 J/mol·K and - 45.37 kJ/mol, respectively.