Hemin-Engineered UiO-66(Ce) as a Highly Active Nanozyme for Electrochemical Sensing of Hydrogen Peroxide and Hydrogen in Beverages

A hemin (Hm)-engineered cerium-based metal-organic framework (MOF), UiO-66(Ce)@Hm, was prepared and used as a nanozyme for electrochemical sensing of hydrogen peroxide (H₂O₂) and dissolved hydrogen (H₂) in beverages. UiO-66(Ce)@Hm showed enhanced electrocatalytic activity toward H₂O₂ because of the synergistic catalytic effects of Hm and UiO-66(Ce). The resulting sensor enabled H₂O₂ detection from 0.5 to 250 μM with a detection limit of 0.32 μM, and was successfully applied to milk analysis. In addition, dissolved H₂ in hydrogen-rich water (HRW) promoted the catalytic conversion of o-phenylenediamine/H₂O₂ to electroactive 2,3-diaminophenazine, allowing H₂ determination from 45 to 900 μM with a detection limit of 26.2 μM. These results demonstrate the potential of UiO-66(Ce)@Hm for food safety monitoring and quality assessment of HRW beverages.