Food quality surveillance: A smart fluorescent probe for viscosity-based spoilage detection

Viscosity is a key indicator reflecting food quality. In this study, we designed a powerful near-infrared-emitting viscosity-sensitive fluorescent probe (DCYM), which exhibited high selectivity and viscosity sensitivity (R² = 0.96), broad pH tolerance (pH 4.0-10), excellent photostability (retaining >95 % intensity after 9000 s illumination). Utilizing its superior properties, DCYM was applied to delineate spoilage-specific viscosity signatures across 12 food matrices, including liquid beverages, meat, and vegetables, mechanistically linking rheological changes to pectin hydrolysis and protein denaturation. By establishing precise correlations between molecular-scale viscosity changes and food deterioration pathways, we provided a paradigm-shifting framework for intelligent food monitoring. Hence, this research fundamentally advances the field of food quality control by developing novel analytical approaches, creating a groundbreaking framework for future intelligent food monitoring technologies.