Catalysis of oxygen reduction reaction by iron porphyrin and its sensing application

Abstract

Hemin, or iron porphyrin, serves as a non-noble metal catalyst for the oxygen reduction reaction (ORR). The stability of hemin is maintained in high salt concentrations, functioning as an ORR redox catalyst in the aqueous phase. Hemin facilitates the development of an oxygen sensor that transitions the ORR mechanism from a 2-electron to a more efficient 4-electron process. This sensor demonstrates excellent reproducibility (RSD<5%), with a wide linear range of 38.9–613 μM, a sensitivity of 0.136 ± 0.003 μA μM−1, and a limit of detection (3SB/m) of 11.8 μM.