On-substrate fabrication of a bio-conjugated Au nanoring solution for photothermal therapy application

Abstract

The on-substrate fabrication of a bio-conjugated Au nanoring (NRI) solution with the localized surface plasmon (LSP) resonance wavelength in the 1200-1300 nm range is demonstrated. Also, the effects of photothermal therapy through LSP resonance-induced absorption enhancement are illustrated by applying the bio-conjugated Au NRIs to human liver cancer cells and illuminating the cells with a laser of 1315 nm in wavelength. The Au NRI fabrication is based on the techniques of nano-imprint lithography and metal secondary sputtering. The procedure for on-substrate surface modification of Au NRIs leads to a high production yield of bio-conjugated NRIs. The threshold levels of the local laser intensity for injuring cancer cells based on the LSP resonances of Au NRIs of two different samples are determined.