SiO2 thin-films were prepared by thermal oxidation method. It showed uniform color based on the thin-film interference of visible light. Then we made biotin antenna on the top of SiO2 thin-film. Biotin is one of the vitamins and it has high association constant with protein avidin. After immersed the substrate into avidin solution, certain color changes based on the self-assembling of avidin on its surface were observed. By the immersing these substrates into mono-dispersed polystyrene particle solution, a polystyrene particle layer was formed onto avidin SAMs and it brought dynamic interference color change. As a result, this substrate could sense the avidin molecules over 1.0×10-8M of its concentration by naked eyes.