Silver film deposited over large-area self-assembled array of silica nanospheres as ultrasensitive SERS substrate

Abstract

We have demonstrated an approach to prepare ultrasensitive surface enhanced Raman scattering (SERS) substrate via depositing Ag over silica (SiO2) nanospheres array template by magnetron sputtering. The nanospheres self-assembled on slightly-tilted silicon (Si) substrate with low-temperature thermal treatment. Large-area uniform Ag nanoclusters array was obtained with 40nm Ag covered the nanospheres (360nm in diameter). Ultrasensitivity was verified by successfully detection of Rhodamine 6G (R6G) with a limit of 10−11M.