A facile route to synthesize silver nanoparticles in polyelectrolyte capsules

We are reporting a novel green approach to incorporate silver nanoparticles (NPs) selectively in the polyelectrolyte capsule shell for remote opening of polyelectrolyte capsules. This approach involves in situ reduction of silver nitrate to silver NPs using PEG as a reducing agent (polyol reduction method). These nanostructured capsules were prepared via layer by layer (LbL) assembly of poly(allylamine hydrochloride) (PAH) and dextran sulfate (DS) on silica template followed by the synthesis of silver NPs and subsequently the dissolution of the silica core. The size of silver nanoparticles synthesized was 60 ± 20 nm which increased to 100 ± 20 nm when the concentration of AgNO3 increased from 25 mM to 50 mM. The incorporated silver NPs induced rupture and deformation of the capsules under laser irradiation. This method has advantages over other conventional methods involving chemical agents that are associated with cytotoxicity in biological applications such as drug delivery and catalysis.

Schematic describes in situ synthesis of silver NPs in LbL assembled polyelectrolyte capsules by novel polyol reduction method.Figure optionsDownload as PowerPoint slideResearch highlights
► A simple and green approach to synthesize silver nanoparticles in situ within the polyelectrolyte capsule shell based on polyol reduction process is demonstrated.
► Precursor concentration has a significant effect on the size and distribution of the silver nanoparticles formed.
► Silver loaded nanostructured capsules can be used as light responsive carriers in the area of drug delivery and catalysis.