Surface wettability studies on aligned gold nanorod array substrate

The detection technology based on surface-enhanced Raman scattering (SERS) is a very promising bio-chemical on-site sensing method. The hydrophobicity of the substrate surface will limit the spreading area of target agent and extend the drying time. Although this will enlarge the density of the target molecular on the substrate and consequently improve the spectrum intensity, the whole detection time is delayed. This is not beneficial to the on-site rapid detection in some specific application area. In this paper, some methods are reported to improve the surface wettability of aligned gold nanorod (AuNR) array SERS substrate. These methods can improve the surface hydrophilicity of the substrate by enhancing the surface free energy and surface microstructure roughness. Good hydrophilicity enables the droplet of sample to spread on the surface of the substrate more quickly, which is conducive to shorten the natural drying time of the droplet and improving the detection efficiency. These studies are of great significance for fast and convenient on-site bio-chemical detection.