Mn-DPA with peroxidase-like activity for fluorescence detection of iron ions in spinach

Iron ion (Fe(III)) plays a crucial role in many physiological processes, and both excess and deficiency of Fe(III) can lead to diseases. Therefore, developing simple and reliable methods for detecting Fe(III) is of great importance. Based on a novel Mn-based material (coordination of manganese with 2,6-dicarboxypyridine, Mn-DPA) prepared in this study with Fe(III)-enhanced peroxidase-like activity, an efficient fluorescence method was developed for Fe(III) detection. The method demonstrated excellent analytical performance in detecting Fe(III), such as superior selectivity and an extremely low detection limit (0.66 nM). Furthermore, the mechanism of Fe(III) enhancing the enzyme-like activity of Mn-DPA was investigated, and the results suggest that the addition of Fe(III) can promote the generation of active intermediates (hydroxyl radicals) during the reaction. Additionally, Mn-DPA based fluorescence method has been successfully applied to detect Fe(III) in spinach, with recovery rates in the range of 90.9 %–115.6 %. The fluorescence method established in this study holds significant application potential for Fe(III) detection.