Smart supramolecular fluorescent dendrimer for dual detection of Fe3 + ion and pH variations in food packaging applications

In this study, a novel supramolecular dendrimer based on polyamidoamine (PAMAM) with perylene core is synthesized and functionalized with a rhodamine-based fluorescent unit to develop a highly selective and sensitive sensor for Fe ³⁺ ions. Spectroscopic analyses confirm strong binding interactions with Fe ³⁺ , resulting in significant changes in both absorption and fluorescence profiles. The sensor demonstrates an exceptional limit of detection (LOD) of 0.0000125 µM and exhibits pH-sensitive fluorescence behavior. Morphological investigations reveal a distinct self-assembly transition from crystalline microstructures to spherical nanoparticles upon Fe³ ⁺ complexation. Furthermore, the PDIG4RG6 sensor is embedded in poly(vinyl alcohol) (PVA) films to fabricate a smart packaging material capable of detecting freshness in real-time through pH-induced fluorescence quenching. The system effectively monitors fish spoilage, offering a rapid, non-destructive, and low-cost method for food quality assessment. This work presents a promising platform for intelligent detecting food spoilage.