Influenza polydiacetylene

Fig. 8 (top) Liposome with polydiacetylene linked monolayer mixed with ligand for receptor detection. (bottom) Colorimetric detection of influenza virus using polymerized liposomes to which have been added increasing amounts of influenza virus from left to right. [18]... 

Reichert A, Nagy JO, Spevak W, Charych D (1995) Polydiacetylene liposomes functionalized with sialic-acid bind and colorimetrically detect influenza-virus. J Am Chem Soc 117 829-830... 

The 1,4 addition of diacetylenic monomers, initiated by UV irradiation, creates polydiacetylene (PDA) polymers. PDA was first prepared in 1969 by Wegner " and since then it has been an area of extensive research. Ringsdorf was the first to prepare PDA vesicles and study its absorption and emission properties in response to environmental changes. Charych and her co-workers pioneered the application of PDA materials for biosensing by detecting influenza vims. ... 

Reichert, A., J.O. Nagy, W. Spevak, and D. Charych. 1995. Polydiacetylene liposomes functionalized with sialic-acid bind and colorimetrically detect influenza-vims. J Am Chem Soc 117 (2) 829-830. Charych, D., Q. Cheng, A. Reichert, G. Kuziemko, M. Stroh, J.O. Nagy, W. Spevak, and R.C. Stevens. 1996. A Htmus test for molecular recognition using artificial membranes. Chem Biol 3 (2) 113-120. 

Figure 11 (Left) Scheme of the polymerized bilayer assembly. The blue phase polydiyacetylene chromatic detection element is deposited over a support monolayer. The polydiacetylene chain Is asymmetrically substituted with urethane side groups partially terminated with receptor-binding ligands. (Right) Absorption spectrum of the blue and red phase PDA with a schematic representation of their chain with (red phase) and without (blue phase) influenza virus attached. Adapted figures with permission from D.H. Charych, J.O. Nagy, W. Spevak, and M.D. Bednarski, Sc/ence 261, 585 (1993), Figure 2 and 3. Copyright 1993 AAAS.

Charych et al. reported a direct colorimetric assay for the detection of influenza virus, using a polydiacetylene bilayer immobilized on a glass microscope slide and functionalized with sialic acid (the vims receptor molecule). Upon binding of the vims, a color change is visible to the naked eye, but could also be quantified by absorption spectroscopy. The authors demonstrated by physical characterization that the packing of the bilayer with bound vims was different from that without vims, resulting in a change of the optical properties of the polymer backbone. 

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