Protein‐Coated Porous‐Silicon Photonic Crystals for Amplified Optical Detection of Protease Activity

Abstract

An optical biosensor for protease activity, capable of detecting picomole quantities of protease, is constructed from a 1D photonic crystal of porous Si. The porous Si layer is coated with a thin film of zein, a natural hydrophobic protein. Proteolytic cleavage produces small fragments that infiltrate the pores of the photonic crystal, producing a distinct color change (see figure). The amount of protease pepsin used on each of the spots is indicated. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2089/2006/c2420_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.