Polydiacetylenes carrying amino groups for colorimetric detection and identification of anionic surfactants

Abstract

A series of diacetylene lipids carrying primary amine, secondary amine or ammonium head groups are prepared and converted to blue polydiacetylene (PDA) sols by UV irradiation. The blue to pink colorimetric transition of polymerized diacetylenes in the presence of anionic surfactants such as sodium dodecanoate (SDC), sodium docecyl sulphate (SDS), and sodium dodecyl benzene sulphate (SDBS) are observed by the naked eye at the micromolar concentration level while there is no change with cationic surfactants and little response with nonionic surfactants. An identification of common anionic surfactants can be accomplished based on a combination of the colorimetric pattern of structurally diverse PDAs using the principal component analysis technique. Moreover, PDA was successfully fabricated on filter paper and the colorimetric response of PDA embedded on the paper was investigated which allowed the direct colorimetric detection of anionic surfactants.