Visible surface diffusion of gold nanostructures on a paper at room temperature through localized surface plasmon resonance

We visually observed color changes of discontinuous gold surfaces on paper substrates through localized surface plasmon resonance (LSPR) at room temperature due to surface diffusion of gold nanostructures. Isolated nanoparticles and an uncompleted nanosheet of gold were obtained by thermal vapor deposition. After preservation for 8 months in air at room temperature, the particle sizes and shapes remarkably changed with color changes. The surface diffusion of the discontinuous gold on the paper would be derived from solid-state dieting, resulting in the growth of the nanosheet defect and coalescence of the nanoparticles. This is due to the total energy minimization of the surfaces of gold nanostructures and the paper and the interface between gold and the paper.