Two-step approach for the nanofabrication of highly ordered ultra-long porous gold nanowires with an adjustable porosity for SERS-based sensors

Recently, nanoporous gold has been pointed out as a promising candidate for the development of SERS-based sensors for the detection of environmental toxins and small molecules [1]. One way to improve the detection ability of such sensors is by engineering the porosity and shape of nanoporous material. In this work we report on a versatile two-step approach for the synthesis of porous nanowires involving plasma deposition of gold-copper alloy on a nanograted substrate followed by a selective electrochemical etching. The relevance of the approach is its ability to prepare highly ordered ultra-long porous gold nanowires with an adjustable porosity and a length up to the macroscale. The resulting gold porous nanowire exhibits a very high roughness and high specific surface area suitable for highly sensitive detection of small molecules by SERS. References: [1] L. Zhang, H. Chang, A. Hirata, H. Wu,Q.-K. Xue and M. Chen, ACS Nano 7, 4595 (2013