ABSTRACT
In cellular communication, receptors that are strategically localized in the cell plasma membrane recognize and respond specifically to the target molecules. Mimicking cell membrane biomolecular recognition poses a great challenge in materials chemistry research and opens the doors to innovation of new diagnostic and therapeutic methods for biomedical purposes. One effective approach has been engineering artificial cell membranes with desirable physical properties, i.e., optical or electrical “reporting” capability [1]. These so-called “smart” materials, similar in structure to the cell membrane of living cells, are able to transduce biological molecular recognition events occurring at the surface of the material into measurable signals. We are particularly interested in the artificial membranes of polydiacetylene (PDA) lipids and have been focusing on utilizing the engineered PDA materials to construct novel sensors. It has been shown that self-assembly of the amphiphilic diacetylenic molecules occurs by the same entropic driving force that results in the formation of biological cell membranes and vesicles [2]. Once the monomers are assembled into an ordered array, they can be polymerized by UV irradiation into a blue-colored polydiacetylene polymer [3-5]. The incorporated receptors in the PDA matrix bind the target materials at the surface of the materials. The biomolecular recognition triggers a chromatic phase transition in the engineered membranes, and thus provides co-
lorimetric detection of the target molecules. Such a detection strategy allows molecular recognition and optical reporting to occur within a single macromolecular assembly. Featuring simplicity of design and good sensitivity, this approach offers a new and general method toward direct, one-step colorimetric detection of a variety of pathogenic agents [6].
