Butterfly-wing hierarchical metallic glassy nanostructure for surface enhanced Raman scattering

The surface-enhanced Raman spectroscopy (SERS) is a technique for the detection of analytes on the surface with an ultrahigh sensitivity down to the atomic-scale, yet the fabrication of SERS materials such as nanoparticles or arrays of coinage metals often involve multiple complex steps with the high cost and pollution, largely limiting the application of SERS. Here, we report a complex hierarchical metallic glassy (MG) nanostructure by simply replicating the surface microstructure of butterfly wings through vapor deposition technique. The MG nanostructure displays an excellent SERS effect and moreover, a superhydrophobicity and self-cleaning behavior. The SERS effect of the MG nanostructure is attributed to the intrinsic nanoscale structural heterogeneities on the MG surface, which provides a large number of hotspots for the localized electromagnetic field enhancement affirmed by the finite-difference time-domain (FDTD) simulation. Our works show that the MG could be a new potential SERS material with low cost and good durability, well extending the functional application of this kind of material.