Synthesis of fluorescein-modified magnetic nanoparticles and study on the their antibacterial effects

A novel fluorescein-modified magnetic nanoparticles were synthesized by the immobilization of fluorescein onto the surface of the magnetite nanoparticles. In the first step, Fe3O4 magnetic nanoparticles were synthesized using chemical coprecipitation of FeCl3 (10.8 g) and FeCl2 (4.0 g) in the alkaline NH3 solution and under nitrogen atmosphere [1,2]. In the second step, fluorescein was immobilized onto the surface of the Fe3O4 nanoparticles. The Size, structure and surface modification of the prepared fluorescein-modified Fe3O4 nanoparticles were studied by FT-IR and XRD analysis. It was found that prepared nanoparticles have the dimensions of 10-17 nm. In addition, the similarity between pure fluorescein FT-IR bands and those of the fluorescein-modified Fe3O4 revealed the surface immobilization of fluorescein on the Fe3O4 nanoparticles. In the third step, the antibacterial characteristics of the fluorescein-modified Fe3O4 nanoparticles were examined by adding different dose of the nanoparticles to the medium containing enterobactor aerogenes. Total population count and plate count procedure confirm notable antibacterial effects of the fluorescein-modified Fe3O4 on the Enterobactor aerogenes.