In situ patterning of hierarchical nanoporous gold structures by in-plane dealloying

We report a novel in situ patterning method that generates hierarchical nanoporous gold (NPG) structures such as sub-micron NPG disks and microscale NPG patterns during dealloying for the first time. Our patterning method also enables the quantification of dealloying rate by scanning electron microscopy (SEM) without the need for depth-resolving imaging modalities. As potential applications, we demonstrate that the hierarchical NPG dot arrays are effective for surface-enhanced Raman scattering (SERS) and metal-enhanced fluorescence (MEF), both are highly sensitive molecular sensing techniques.