Cycle performance of sol–gel optical sensor based on localized surface plasmon resonance of silver particles

Silver particles generated by the evaporation–condensation method were deposited on the sol–gel derived silica film or the silica glass substrate to form SPR sensors, and their SPR sensing property was examined. When the sensing measurement was repeated, deposited silver particles gradually came off, and optical absorbance was decreased. To avoid these phenomena, silver particles were overcoated with silica thin film prepared by sonogel method. As a result, by adjusting the silica concentration of starting sol or the thickness of sono-silica overcoating, cycle performance of the sensor was improved.