The Study, Based On The Sers Substrate Of The Aao Template

The investigation of nanowire and nanoarray materials is one of the hotspots of material science. These nanomaterials also have high enhancement factor of surface enhanced Raman scattering (SERS) while they are used as SERS substrate. To study these substrates is important for the three main research areas of SERS. Direct current electrochemistry deposition method, solvothermal method and pyrolytic process were used to fabricate SERS substrates inside the hole of anodic aluminum oxide (AAO) template. Grey silver colloid was fabricated by Lee and Meisel method.The SERS effect of colloid and purified colloid were also discussed.In this Master Dissertation, the main research works and conclusions are listed as following:1. The highly ordered and apertures adjustable AAO template was fabricated by two-step anodization. The SEM graphs show that the barrier layer is close packed hexagon structure. The XRD results show that both of porous layer and barrier layer of AAO template are amorphous materials.2. Current density-time (J-T) monitoring was used to monitor electrochemical polish process, oxidation process, removing oxidation layer and barrier layer process during the fabrication of template. J-T standard curves in each process were obtained under our laboratory conditions. This real time monitoring is the base of analyzing template growth mechanism, quality examination and optimizing preparation technology. With the help of real time monitoring, sophisticated and precise fabricate template become realism.3. Nickel nanoarrays were successfully synthesized in two-step anodization AAO template without removing aluminum base by DC electrochemistry deposition method. XRD results show that the nickel nanoarrays are polycrystalline.4. Silver nanoparticles were successfully synthesized in AAO template by pyrolytic process. The AAO template was etched by NaOH solution, and then centrifugal and ultrasonic treated. The solution which contains silver nanoparticles can be used as SERS substrates. But the homogeneity of these substrates is very bad. 5. Silver nanopspheres were successfully synthesized in AAO template by solvothermal method. The AAO template undering etched by NaOH solution, and then centrifugal and ultrasonic treated. The solution which contains silver nanopsphere can be used as SERS substrates. If the AAO template was annealed, these substrates mainly contain nanowires, nanorods and nanoparticles.6. Melamine was used as probe molecular and SERS substrates are base on AAO template which fabricated by DC electrochemistry deposition, olvothermal and pyrolytic process. A portable Raman spectrometer was used to do SERS test. Both of the substrates have Raman enhancement of 103, the minimum detectable amount of melamine reaches 10-6g.7. When silver colloid was used as SERS substrates, the minimum detectable amount of melamine reaches 6*10-12g, and its Raman enhancement reaches 3.7*106. If the silver colloid was treated by purification, the minimum detectable amount reaches 1.1*10-12g, and its enhancement reaches 108. This result reaches sub-monomolecular layer level. If combined with solid phase extraction technology of melamine in foods, this method can be applied to on-site, rapid, precise detection of melamine.