Abstract
Iridescent photonic nano-silica is proposed for chemical and biological sensing. The iridescent photonic nano-silica consists of periodically low and high refractive index nano-silica layers. Its optical characteristics can be controlled by electrochemical etching and thermal oxidation. The validity and the sensitivity of the proposed iridescent photonic nano-silica are demonstrated for organic solution and proteins at 20pg/ml concentrations. © 2007 IEEE.