Xanthine (XA) and hypoxanthine (HA) are key biochemical markers of meat freshness, yet rapid, wide-range, and enzyme-free quantification in complex meat matrices remains challenging. Here we report a density functional theory (DFT)-guided Cu–MoS 2 /g-C 3 N 4 heterostructure electrochemical sensor for broad-range non-enzymatic detection of XA and HA. The heterojunction prepared via a hydrothermal and ultrasonic strategy provides an efficient charge-transport pathway and enriched catalytic interfaces. DFT calculations reveal pronounced interfacial charge redistribution and strong adsorption of XA and HA on the Cu–MoS 2 /g-C 3 N 4 surface, with adsorption energies of − 0.98 eV for XA and − 2.16 eV for HA, explaining the boosted electrooxidation response. The sensor achieves low detection limits of 0.15 μM for XA and 0.28 μM for HA and wide linear ranges from 0.913 to 1643.5 μM and from 0.918 to 1653.1 μM, respectively, and enables simultaneous quantification from 0.5 to 400 μM with excellent linearity. Good stability, reproducibility, and anti-interference capability are obtained. In real meat samples, recoveries from 90.7% to 108.3% for XA and from 91.3% to 111.4% for HA agree well with high-performance liquid chromatography, supporting rapid meat freshness evaluation.
Yang et al. (Fri,) studied this question.