Directional controllable electrodeposition growth of homogeneous Au nano-rampart arrays and its reliable SERS applications

High-yield large-area uniform metal nanoarrays have shown attractive application potential in many fields. Electrodeposition growth has unique advantages in the construction of metal nanostructures due to its high efficiency. However, the uniformity and stability of electrodeposition are still remain challenging. Here, an efficient, stable and cost-effective directional electrodeposition route was proposed to construct large-scale uniform metal nanoarrays, which could be further used as reliable SERS substrates. Assisted with uniform porous anodized aluminum oxide (AAO) templates, a series of homogeneous Au nano-rampart arrays (Au-NRAs) were prepared controllably by directional electrodeposition growth technology. Using the prepared Au-NRAs as SERS substrates, the results showed that the optimal electrodeposition growth is 600 s. At this time, Au-NRAs showed highest SERS activity and the low relative standard deviation (RSD) value of Raman intensity at 619 cm−1 mode of R6G (with concentration of 10-5 M) was 2.08%, which indicated excellent SERS stability. This method integrated not only cost-effectiveness, but also good directional controllability and repeatability, showing great potential in constructing large-area uniform metal nanostructures.