The Polymer Society of Korea

Abstract

Amines are important indicators of industrial contamination and food spoilage, yet rapid on-site detection remains challenging. For example, biogenic and inorganic amines, including trimethylamine (TMA) and hydroxylamine (HA), are typically analyzed by HPLC or GC-MS, limiting field applicability. Aldehyde-amine reactions involve nucleophilic interactions forming imine (C=N) or enamine (C=C-NR₂) structures under mildly acidic conditions. Here, we report polydiacetylene-benzaldehyde (PDA-BA) liposome-loaded alginate beads co-encapsulating an organic acid catalyst, 5-methoxyanthranilic acid (5-MA). Benzaldehyde functionalized enhanced perturbation of the conjugated ene-yne backbone, inducing blue-to-red color transition within 5 minutes. RGB-based analysis showed concentration-dependent responses for TMA and HA. This PDA-BA alginate bead sensor provides a rapid, low-cost, and instrument-free platform for on-site detection of hazardous amines molecules.