Keratin capped silver nanoparticles--synthesis and characterization of a nanomaterial with desirable handling properties.

We report for the first time the stabilization of silver nanoparticles in good yield, average diameter 3.5 nm, using wool keratin hydrolysates as stabilizers. The nanoparticles are extremely stable as a suspension and can be lyophilized into a powder and easily reconstituted in solvent with no change in spectral properties relative to the initial suspension. The nanoparticles interact with nitrogen and oxygen moieties of the keratin hydrolysates under the pH conditions used in the synthesis and appear to act as cross-linkers between adjacent chains. The product has excellent handling properties which we believe will make it a very attractive biocompatible coating/additive, providing prolonged antimicrobial efficacy to a wide variety of products such as textiles, plastics, paints, orthopedic devices and others.