The invention discloses a silver-gold porous
nanorod array, a preparation method and a purpose of the silver-gold porous
nanorod array. The array comprises porous gold nanorods coated with 3-15nm silver films and arranged on a
methyl methacrylate substrate coated with a
gold film, wherein the nanorods are 150-250nm in length, and 50-70nm in
diameter; and holes are 5-20nm in
diameter. The method comprises the steps of placing an aluminum
oxide template coated with a
gold film in a mixed electrolytic solution for electro-deposition, obtaining an aluminum
oxide template coated with the
gold film and provided with a gold-silver
alloy nanorod array deposited in holes, placing the aluminum
oxide template in a
nitric acid solution for reaction to obtain an aluminum oxide template coated with the gold film and provided with a porous
gold nanorod array in holes,
coating the other side of the gold film with liquid
methyl methacrylate, solidifying, then sequentially placing the aluminum oxide template in a
silver nitrate electrolytic solution for the electro-deposition and aqueous alkali for removing the aluminum oxide template, or sequentially placing the aluminum oxide template in aqueous alkali for removing the aluminum oxide template,
coating a
silver film by an
ion sputtering method, and obtaining the objective product. The array can serve as an SERS (Surface Enhanced
Raman Scattering) activity substrate for detecting trace organic matters.