Enabling nanostructured materials via multilayer thin film precursor and applications to biosensors

A thin film based nanoporous alumina template has been developed which allows the in situ removal of an electrically insulating alumina barrier layer at the pore bases. This barrier free nanoporous system has great utility for electrodeposition of a wide variety of nanowire materials. An exemplary multilayer thin film precursor is provided comprising Al (anodization layer), Ti (diffusion barrier) and Pt (active electrode) on a Si substrate. Aluminum anodization in sulfuric acid with a subsequent applied voltage ramping program produces a Pt electrode at the base of the nanopores without the additional steps of alumina removal, barrier layer dissolution, and metal deposition onto the pore bottoms.