Due to their large surface to volume ratio nanostructures are inherently unstable. To insure long term stability of nano-devices, they have to be rendered inert to their environment. In this study, nanoporous gold films(NPGF) and multiwall carbon nanotubes were coated with ALD alumina of varying thicknesses. Subsequently, the plasmonic property of the former and electronic property of the latter was monitored by Transmittance and Raman Spectroscopy respectively. Transmittance spectra revealed that NPGF passivated by ALD-alumina maintains its plasmonic properties, i.e. its LSPR supporting properties remained intact. Raman spectra of ALD alumina passivated MWNTs show no coating induced changes in its characteristic Raman features. This led to the conclusion that ALD alumina is a benign and suitable technique for thin film passivation of NPGF and MWNTs. This result supports the expansion of ALD's domain as a reliable thin film passivation technique in areas of SERS based biosensor research and the passivation of carbon nanotubes.