Polymerized lipid vesicles as colorimetric biosensors for biotechnologicalapplications

Supramolecular chemical assemblies composed of polydiacetylene (PDA) exhibi t rapid colorimetric transitions upon specific interactions with a variety of biological analytes in aqueous solutions. Among the analytes that give r ise to the unique blue-red color changes are lipophilic enzymes, antibacter ial peptides, ions, antibodies, and membrane penetration enhancers. The che mical assemblies include conjugated PDA, responsible for the chromatic tran sitions, and the molecular recognition elements, which are either chemicall y or physically associated with the PDA. Thus, by incorporation of specific recognition elements, the system can be designed in ways allowing for high ly selective identification of analytes. In particular, receptors and epito pes can be incorporated within the sensor assembly, which then determine th e specificity of the colorimetric transitions. The PDA-based molecular asse mblies are robust and can be readily applied to diagnosis of physiological molecules and for rapid screening of chemical and biological libraries, for example, in 96 well-plate platforms. (C) 2001 Elsevier Science Inc. All ri ghts reserved.