A new HBT-quinolinium platform for optical detection of biogenic amines and its application in food quality monitoring.

Biogenic amines (BAs) are critical biomolecules that play key roles in physiological processes and serve as important indicators in food safety, clinical diagnostics, and environmental monitoring. Therefore, sensitive, selective, and rapid tools are required for BA detection. This study explores the synthesis and applications of a new fluorescent probe (DBQ) for detecting BAs, focusing on their fluorescence response mechanisms. DBQ offers a promising alternative due to its high selectivity, sharp color change, low detection limit (0.057 μM for cadaverine), long lifetime (τ ≈ 2.40 ns), rapid response (15 min), low cytotoxicity (over 90 % cell viability in the presence of 10.0 μM of DBQ) and favorable photophysical properties, including large Stokes shift (213 nm in CHCl). In addition, DBQ displays solvent-dependent intramolecular charge transfer (ICT), resulting in solvatochromism. The developed smartphone sensing system was applied to the detection of BAs. The developed sensing test kit responds quickly to the presence of volatile biogenic amines, with notable visible response and high selectivity. In on-site analysis, we were able to successfully use these test strips for non-destructive evaluation of chicken and cheese freshness with the use of a smartphone. Therefore, the current study will contribute to improving food safety and reduce food loss and waste by developing new bioanalytical technologies that offer chemical information about the composition of food, which is extremely valuable for enhancing traceability and extending food shelf life.