Main content area

Fenton-like zero-valent silver nanoparticle-mediated hydroxyl radical production

He, Di, Miller, Christopher J., Waite, T. David
Journal of catalysis 2014 v.317 pp. 198-205
cell viability, hydrogen peroxide, hydroxyl radicals, nanosilver, oxidation, pH, protons, silver, stomach, superoxide anion, tissues
The H2O2-mediated oxidation of zero-valent silver nanoparticles (AgNPs) under acidic conditions (pHs 3.0, 3.5 and 4.0) is investigated here as is the associated production of hydroxyl radicals (HO). Citrate-stabilized AgNPs initially react with H2O2 to form reactive intermediates with these species subsequently (i) reacting with an additional molecule of H2O2 to form surface-associated Ag(I) and O2⁻ with subsequent reduction of a portion of the Ag(I) species to Ag⁰ via electron charging–discharging processes, and (ii) decomposing with the aid of protons to produce HO. The combined generation of HO and release of Ag⁺ from AgNPs under acidic conditions may synergistically affect the viability of cells and tissues. As such, the safety of topical exposure to AgNP-containing commercial products which can access skin or internal organs such as the stomach warrants further investigation with regard to the impact of HO generated by the AgNP-mediated decomposition of H2O2.