Colorimetric response and lipoplex formation with DNA of a high sensitive amine oxide substituted polydiacetylene

A polydiacetylene (PDA) sensor derived from amine oxide amphiphile monomers displayed high sensitive colorimetric response in aqueous medium in presence of various polar solvents including methanol or dimethylformamide, but also upon exposure to other stimuli such as temperature and pH variation. In solution, at the lower pH, the zwitterionic heads of PDA are protonated and the resulted cationic extremities are able to form water insoluble lipoplex with DNA easily detected by naked eyes. The morphology of the PDA structures in solution was observed by transmission electronic microscopy (TEM) and Fourier transformed infrared (FT-IR). The colorimetric response of each sample was studied using UV–vis absorption.