Polydiacetylene (PDA)-based sensor has the characteristics of color change and self-fluorescence emission by exterior stimuli. The sensing experiment using 10,12-pentacoasadiynoic acid (PCDA) liposomes conjugated with functional biomolecules like antibodies or aptamers was conducted on a solid substrate. The PCDA mixed with dimyristoylphosphatidylcholine (DMPC) was also used. The PCDA liposome containing 20-30% DMPC showed a much quicker change of fluorescence upon stimuli than pure PCDA liposome. To characterize how DMPC affects the reaction time, we carried out FTIR (Fourier transformed infrared spectroscopy) and the Differential Scanning Calorimetry (DSC) experiments. The results suggested that hydrogen bonds between PCDA backbone was weakened so that the flexibility of PCDA liposome increased with DMPC.

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