Controllable Decoration of Au NPs on Zinc Oxide Nanorods Template by Magnetron Sputtering Technique for Reusable-SERS Active Surface Enhancement

Surface Enhanced Raman Scattering (SERS) is a new invention developed to expand the Raman signal. The SERS chip has a performance to enhance the Raman signal up to a million times. Nevertheless, the chip has some disadvantages which are high cost and it is disposable device. In this research, the controllable decoration of gold nanoparticles on zinc oxide nanorods template for a reusable SERS chip is investigated. Time periods to decorate gold particles are controlled by using DC magnetron sputtering technique from 15 to 450 s. The zinc oxide nanostructures are grown by hydrothermal. The physical structures of the reusable SERS chip are analyzed by Field Emission Scanning Electron Microscope (FE-SEM). The sizes and thicknesses of the gold particles attached to the ZnO nanorods are measured from FE-SEM images. The efficiency to amplify Raman signal of the reusable SERS chip is tested by dropping methylene blue (MB). UV light is used to activate self-cleaning property of the reusable SERS chip. From the results, sputtering gold nanoparticles for 270 s shows the highest performance to amplify Raman signal of methylene blue, up to 1x10(-6) M, however; it takes 450 minutes of UV cleaning before reuse again. On the other hand, sputtering gold nanoparticles for 15 s shows the fastest clean surface after UV cleaning, though the chip can amplify the Raman signal up to 1x10(-5) M.