Abstract
Nanometer sized gold fine particles are well know to show a particular optical absorption in visible range due to their surface plasmon resonance (SPR). The change of SPR is very sensitive to refractive index of a near-field region of gold particles surface. Thus, the application of gold fine particles have received a lot of attention as a chemical-biosensor. In order to make a SPR sensor tip which consists of simple equipments and can detect target substances with ease, silica gel thin films loading gold fine particles were prepared on a glass substrate by a sol-gel method and subsequent thermal-reduction process. The prepared thin films exhibited the particular optical absorption due to the localized surface plasmon resonance (LSPR) of a nanometer sized gold particle. Additionally, the absorption maxima showed liner red shift depending on refractive indices of respective solvents.
