Direct printing of plasmonic micropatterns of Au/Ag nanoparticles via precision photoreduction

Plasmonics structures of noble metal nanoparticles have wide applications in biosensor applications. However, it remains a challenge to rapidly fabricate plasmonic micropatterns of noble metal nanoparticles. In this paper, we present a precision photoreduction method to directly print multiscale engineered plasmonic micropatterns of gold and silver nanoparticles. With an in-house digital ultraviolet (UV) lithography technology, UV patterns are used to temporally and spatially regulate the photoreduction of gold or silver nanoparticles to create plasmonic micropatterns on a titanium dioxide-capped substrate. The dimension of gold and silver nanoparticles can be precisely controlled since the UV irradiation can fastly switched off to stop the growth once the silver nanoparticles achieve a target size. This technology enables one-step production of multiscale engineered large-area plasmonic substrates and thus is promising for a great many applications ranging from structural color generation to plasmonic biosensing.