Diacetylenes are a promising class of colorimetric UV responsive
materials due to their distinct color change with tunable sensitivity [4]. Color transitions of polydiacetylenes (PDAs) by heat [5], solvent
[6], mechanical stress [7], molecular recognition [8], and pH [9]
have been extensively investigated and PDAs have been applied
as sensing materials in various forms [10]. Self-assembled amphiphilic
diacetylene lipids are readily polymerized to form ene-yne
conjugated PDAs with intense color. Although the color change of
PDAs from blue to red by prolonged UV irradiation have been noted,
their color transition mechanism remains a topic under debate [11]
and their applications for UV dose sensors have not been investigated.
Here, we would like to report our study on two series of
diacetylene amido lipids (Fig. 1) containing mono- and diamide
head groups with variable lengths of methylene spacers in comparison
with their diacetylene fatty acid analogue aiming to tune
the colorimetric responses of this class of compounds toward UV
doses.