Characterization of Iron nanoparticles produced with green tea extract: a promising material for nitric oxide delivery

摘要

Iron nanoparticles were synthesized by green tea extract and used as nitric oxide (NO) donor. The nanoparticles were obtained by the reduction of Fe~(2+) Fe~(3+), or a mixture of Fe~(2+)/Fe~(3+) by green tea extract, at room temperature within few minutes. The as-synthesized iron nanoparticles were characterized by X-ray diffraction, transmission electron microscopy with electron energy loss spectroscopy, scanning electron microscopy with energy dispersive X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, dynamic light scattering, and ultraviolet-visible spectroscopy. The results showed the formation of iron nanoparticles with average hydrodynamic size of 53.7 ± 10.4 nm, and the presence of polyphenols as capping agents. Free thiol groups on the surface of as-synthesized iron nanoparticles were nitrosated through the addition of an acidified nitrite solution, yielding S-nitroso-iron nanoparticles. The amount of NO covalently bound to the surface of green tea synthesized iron nanoparticles was evaluated by a specific NO electrochemical sensor. The S-nitroso-iron nanoparticles spontaneously released NO in aqueous solution at levels required for biomedical applications. This biogenic iron nanoparticle might find important applications not only in remediation of contaminated soil and water, but also as NO-delivery material able to generate therapeutic amounts of NO in biomedical applications.