The colorimetric and ratiometric fluorescence dual-mode detection of hypoxanthine through catalytic reactions for assessing aquatic product freshness

Timely and accurate assessment of the freshness of aquatic products with complex matrices remains significant challenge. In this study, we developed a dual-mode detection method for hypoxanthine (Hx) based on dual-decomposition mechanisms and simple catalytic reactions. The colorimetric mode, requiring 15 min, is ideal for on-site assessments, while the ratiometric fluorescence mode, equipped with a built-in reference signal, effectively reduces interference from complex matrices. This dual-mode approach enables highly sensitive Hx detection, with detection limits of 1.506 μM and 3.03 μM, respectively, and has been successfully applied to monitor spoilage in real samples under varying storage conditions. The method exhibits excellent reproducibility, with intra-day and inter-day relative standard deviations of 1.05 %–4.30 % and 1.40 %, respectively. Compared to triple quadrupole liquid chromatography-mass spectrometry, this method demonstrates a recovery rate of 88.30 % to 115.08 %, highlighting its significant potential for timely and reliable detection of freshness deterioration and safety monitoring in aquatic products.