Synthesis and application of polydiacetylenes containing amino group for sensing anionic surfactants

Abstract

In this contribution, the colorimetric sensor array for anionic surfactants detection based on polydiacetylene (PDA) was prepared. PDA sols containing amino group such as primary amine, secondary amine, or quaternary ammonium as the polar head group were prepared from diacetylene lipid monomers upon 254 nm UV irradiation. The addition of anionic surfactants such as sodium dodecanoate (SDC), sodium dodecyl sulfate (SDS), or sodium dodecyl benzene sulfonate (SDBS) into the PDA sols induced color transition from blue to red at micro molar level concentration. The colorimetric changes of PDA sols were also monitored by UV-visible spectrophotometer as well as photograph recorder. The addition of cationic surfactants such as dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), and hexadecyltrimethylammonium bromide (HTAB), however did not show any colorimetric change while nonionic surfactants such as tween20, brij@58P, and tritonX-100 induced small color change. An identification of common anionic surfactants can be accomplished based on a combination of colorimetric pattern of structurally diverse PDAs using principal component analysis technique. Moreover, PDA was successfully fabricated on filter paper and the colorimetric response of PDA coated on filter paper was tested with solution of surfactants and commercial cleaning agent products at various concentrations. These allowed the direct colorimetric detection of anionic surfactants using the paper-based PDA sensor.