Study on the effect of Ag nanoparticles density on ZnO/Ag nanostructure to enhance raman signals of SERS substrate on abamectin

Abstract

This study investigated the effect of changing the density of Ag nanoparticles on the ZnO/Ag nanorod structure on the SERS substrate signal amplification ability. First, ZnO nanorods were fabricated by the sol - gel method combining with the chemical bath deposition method. Next, the Ag nanoparticles were decorated on ZnO nanorods by the DC magnetron sputtering method. The density and size of the modified Ag nanoparticles on the ZnO nanorods were changed by adjusting the sputtering times to 5, 10, 15 and 20s respectively. The optical properties of the material are characterized by UV - Vis and PL measurements. The surface morphology of ZnO nanorods and Ag nanoparticles were investigated by scanning electron microscope (SEM). X-ray diffraction measurement (XRD) is used to examine the crystal structures of materials. The composition and distribution of the chemical elements inside the material were investigated by Energy-dispersive X-ray spectroscopy (EDX). The ability of SERS substrates to amplify Raman signals was evaluated by measuring the R6G solution and investigating application for abamectin with a laser excitation wavelength of 532 nm. The results showed that SERS ZnO/Ag substrates with sputtering time of 15s gave the best ability to amplify SERS with the detection of R6G solution at 10􀀀9 M and abamectin at 50 ppm.