Specific aspects of human immunoglobulin interactions with Fe 3 O 4 /≡Si(CH 2 ) 3 NH 2 nanocomposite surface

In a one-step process, nanoscale magnetite was modified with 3-aminopropyltriethoxysilane to introduce amino groups onto its surface. The resulting nanocomposite exhibited a particle size of approximately 13.6 nm, with agglomerates measuring 150 nm in size. The nanoparticles were densely packed, creating gaps (pores) between them of up to 13 nm and a specific surface area of 114 m 2 ⋅g −1 . The nanocomposite possessed approximately 0.8 mmol⋅g −1 of amino groups. Electrokinetic potential data confirmed the presence of basic groups, and the isoelectric point was observed at pH 10. The adsorption of human immunoglobulin in a 0.9% NaCl solution was investigated using the synthesized nanoparticles, with a maximum adsorption capacity reaching 40.5 mg⋅g −1 . Infrared spectroscopy data of the Ig-loaded sample and the fitting of the adsorption isotherm using the Langmuir adsorption model indicated chemisorption of the immunoglobulin on the surface of the Fe 3 O 4 /≡Si(CH 2 ) 3 NH 2 particles.