Interaction of quercetin with silver nanoparticles in reverse micelles

The interaction of quercetin (Qr), a natural flavonoid, with silver nanopar ticles in a system of reverse micelles is studied. The Ag-n(m+) nanoparticl es are produced by gamma-irradiation of AgNO3 aqueous solutions solubilized in a saturated hydrocarbon by using a surfactant (sodium bis(2-ethylhexyls ulfosuccinate)). It is found that the introduction of Qr leads to the disap pearance of the absorption band belonging to nanoparticles (at lambda(max) = 420 nm) and the appearance of a new band in the UV spectrum (at lambda(ma x) = 295 nm). To elucidate the mechanism of the interaction of Qr with Ag-n (m+) particles, the interaction of Qr with silver ions in aqueous and micel lar solutions is studied spectrophotometrically. The results obtained sugge st that the interaction of the initial nanoparticles with quercetin yields new particles (presumably smaller in size and having an absorption band at lambda(max) = 295 nm) through the formation of Qr-silver ion complexes. The addition of an excess of a AgNO3 aqueous solution to the quercetin micella r solution; leads to the formation of silver aggregates with spectral chara cteristics similar to radiation-generated nanoparticles.