Optical Properties of Thin Gold Nanoshell Arrays and Their Application as NIR SERS Substrate

Abstract

Abstract. The metallic hollow-core nanoshell arrays were fabricated by depositing relatively thin gold films onto a cleaned silicon support covered with a close-packed monolayer of 200 nm diameter polystyrene spheres and then removing the spheres. The relationship between their morphologies and optical properties was discussed. Then, the surface enhanced Raman scattering signals of 4-aminothiophenol (4-ATP) molecules adsorbed on the nanoshell arrays were obtained with the excitation wavelength of 785 nm and 1064nm, respectively. The results show that the localized surface plasmon resonance wavelength of gold nanoshell arrays can be precisely tuned over a wide range from visible region to infrared region by controlling the shell thickness of the nanoshell arrays, as the shell thickness increases, the resonance wavelength red shifts and the spectrum width broadens due to the electric field coupling effect among the nanoshell particles, the surface enhanced Raman scattering signals can be obtained obviously at two different infrared wavelengths of 785nm and 1064nm, indicating that the fabricated nanoshell arrays can be used as the potential low-cost surface enhanced Raman scattering substrates.