Studies on recognition and dynamic analysis of polydiacetylene Langmuir-Schaefer films functionalized with glycolipid

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 a-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 9 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.