Abstract: As a potential materials for optic biosensor, the surface properties of the polydiacetylene films fuctionalized with glycolipid on pure water are interesting and important. Pressure area isotherms of mixed α D mannoside hexadecyl(MC₁₆) and 10,12 pentacosadiynoic acid(PDA) monolayers were studied. The interfacial behavior at the air/water interface show that MC₁₆ /PDA monolayers on the water surface have a good miscibility. The interactions of MC₁₆ with Escherichia coli(E.coli) jm 109 were studied by rapid colorimetric transitions on the MC₁₆ /PDA Langmuir Schaefer (LS) films. This colorimetric transition can be quantified by UV Vis absorption spectra. The kinetic experiments show that the color change induced by the addition of E.coli reaches a plateau after 15 min, although the change becomes apparent within 3 min. Kinetics of the process was discussed. We estimate that one Escherichia coli can only bind two MC₁₆ molecules.

Key words: Glycolipid, Langmuir Schaefer film, Molecular recognition