Silver-gold porous nanorod array, preparation method and purpose of silver-gold porous nanorod array

Abstract

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.

Description

technical field [0001] The invention relates to a nanorod array, its preparation method and application, in particular to a silver-gold porous nanorod array, its preparation method and application. Background technique [0002] In recent years, detection methods based on the nanostructured surface-enhanced Raman scattering (SERS) effect have attracted widespread attention because of their "fingerprint" recognition ability, high sensitivity, and ease of rapid detection. Theoretical and experimental studies have shown that the SERS effect mainly comes from the enhanced electromagnetic field generated between nanounits. The gaps between nano-units will generate a strong local coupling electric field, which is usually called "hot spot". Platinum Coated, Nanoporous Gold Nanorod Arrays: Synthesis and Characterization", Adv.Mater.2007, 19, 1612–1615 ("Synthesis and Characterization of Platinum Coated Porous Gold Nanorod Arrays", Journal of Advanced Materials, Volume 19, 2007 1612...

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Problems solved by technology

However, both the platinum-coated porous gold nanorod array and its synthesis process have shortcomings. First, although the product has excellent performance in the field of catalysis, it is greatly limited by the platinum coating. The key role played by the porous gold nanorod array in the SERS effect; secondly, the size of the porous gold nanorods in the product is too large, and the top of the rods is often bonded, which affects the generation of electromagnetic field enhancement between the porous gold nanorods ; Again, the thickness of the gold film supporting the porous gold nanorod array is relatively thin, which is difficult to ensure the stability of the overall structure of the product; again, when electrodepositing the gold-silver alloy nanorod array, due to the use of potassium gold cyanide and silver cyanide Potassium cyanide electrolyte, not only easily causes environmental pollution, but also restricts the application of the product; again, the process of corroding the aluminum oxide film plate and then corroding the gold-silver alloy nanorods has caused the porous gold nanorods top Occurrence of bonding and lodging phenomena; finally, products with higher SERS active substrates could not be synthesized

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