Synthesis of metallic nanoparticles in reverse micelles in the presence of quercetin

A new reducing agent for the synthesis of metallic nanoparticles in reverse micelles is suggested. Stable silver and copper nanoparticles were obtained in the presence of air oxygen in water/AOT/n-alkane system by the reduction of silver and copper salts with quercetin (Qr), natural plant pigment from the group of flavonoids. Particle formation in the presence of Qr in micellar solution was detected by the characteristic changes of optical absorption spectra after the addition of AgNO3 or Cu(NO3)2 as water solutions. Changes of absorption spectra with time and Qr concentration are also presented. Analysis of the absorption spectra of silver nanoparticles by means of the Mie theory allows us to suggest that (1) the particles obtained are small in size (r=1–1.5 nm), (2) changes of absorption spectra with time or with Qr concentration are caused by the increase of particle concentration and (3) at 3 mM metal salt concentration in the micellar solution part of silver ions is not involved in the process of particle formation.