One-pot functionalization of superparamagnetic cobalt ferrite nanoparticles

Application of functionalized magnetic nanoparticles (NPs) has proven effective for immobilizing biological macromolecules such as enzymes, proteins, and DNA. Here, cobalt ferrite (CoFe₂O₄) nanoparticles functionalized with amino (NH₂) groups (CoFe₂O₄@NH₂) were synthesized as a control for the development of bifunctionalized NH₂/SH platforms intended for plasmonic studies of the response-regulating proteins FixJ and DevR. A one-step microwave-assisted solvothermal method using APTES as the functionalizing agent enabled synthesis in only 40 min. XRD and TEM confirmed crystalline CoFe₂O₄ with a mean particle size of 16.7 nm, while magnetic measurements indicated superparamagnetic behavior with a saturation magnetization of 43 emu g⁻¹. DLS results suggested good colloidal stability in aqueous medium. FTIR confirmed successful APTES functionalization while preserving the spinel ferrite structure. Ongoing work focuses on morphological characterization, evaluating the effect of APTES on magnetic properties, and introducing SH groups to obtain bifunctional nanoparticles.