Shape controlled gold nanostructures on de-alloyed nanoporous gold with excellent SERS performance

In this study, nanoporous gold (NPG) has been prepared by chemical de-alloying the Au based metallic glass precursor, Au20Cu48Ag7Pd5Si20(at.%), which was rapidly solidified from the melt in the form of ribbons. On the nanoporous gold, shape controlled gold nanostructures were electrodeposited by adjusting the applied potentials and deposition times. Using Rhodamine 6G (R6G) as probe molecule, the surface enhanced Raman scattering (SERS) activities with different Au nanostructures on nanoporous gold were compared. The electrodeposited Au dendritic nanostructures on NPG after 3000s exhibited strongest SERS effect and high reproducibility. Using this best SERS active substrate for melamine sensing, the detection limit of 10-7 M was achieved.