Simultaneous and visual detection of cysteamine based on Michael addition reaction with polydiacetylene liposome

In this study, we report the fabrication of a highly sensitive colorimetric and fluorometric sensor comprising self-assembled polydiacetylene (PDA) liposomes for the measurement of cysteamine concentration. The N-maleimidomethanol (HM) moiety was used as the Michael addition acceptor, which reacts with the thiol groups in cysteamine to generate maleimide–thiol conjugation resulting in the conformational transition of the conjugated backbone. Furthermore, this chemosensor system displays a clear blue-to-red colorimetric transition in the presence of cysteamine among various biothiols with high selectivity and sensitivity owing to the structural specificity of cysteamine. The resulting PDA solutions were analyzed via FE-SEM, UV-vis, fluorescence and Raman spectroscopy, and chromoisomerism for naked-eye visualization. This chemosensor provides a convenient method for the detection of cysteamine in aqueous solution and in real samples.