Molecularly templated materials in chemical sensing

Biologically-based recognition elements (e.g., antibodies, aptamers, enzymes, etc.) are used as the recognition element within a wide variety of assays and sensor systems. There are, however, compelling reasons for researchers to develop inexpensive, robust, and reusable alternatives for these expensive and unstable biorecognition elements. This review summarizes recent research efforts on the development of molecularly templated (sometimes called molecularly imprinted) organic and inorganic polymers as possible replacements for expensive/labile biorecognition elements. The review begins with a briefing on biosensing and the pertinent issues and limitations. The focus then swings toward molecularly templating within organic and inorganic (xerogels) polymers to create materials with analyte binding characteristics akin to a biorecognition element. The review then describes several recent developments wherein analyte recognition and an analyte-dependent transduction methodology are simultaneously incorporated directly within the templated materials. The review ends by outlining the current state-of-the-art and the remaining issues and impediments. (C) 2007 Elsevier B.V. All rights reserved.