Light-induced polarization-directed growth of optically printed gold nanoparticles

IANINA L. VIOLI; GARGIULO, JULIAN; CATALINA VON BILDERLING; CORTES, EMILIANO; FERNANDO STEFANI

Porquerolles

Workshop; 1st Summer School 'Photothermal Effects in Plasmonics'; 2018

Optical printing has been proved a versatile andsimple method to fabricate arbitrary arrays ofcolloidal NPs on substrates [1]. Here we show that isalso a powerful tool for studying chemical reactionsat the single NP level.We demonstrate that 60 nm gold NPs immobilizedby optical printing can be used as seeds to obtainlarger NPs by plasmon-assisted reduction ofaqueous HAuCl4.The final size of each NP is simply controlled bythe irradiation time (Fig 1). As they grow, the NPsreshape their morphology from nearly sphericalto spheroidal with their major axis parallel to thepolarization of the light used to induce the reaction.This enables the in-situ anisotropic reshaping of theNPs in pre-determined orientations [2].