Eco-friendly quantification of hydrogen peroxide in milk using green-synthesized iron nanoenzymes

Abstract

In this work, iron nanoparticles (FeNPs) were synthesized by a green method using Eucalyptus grandis leaf extract as a reducing and stabilizing agent. The FeNPs were employed as nanoenzymes for oxidizing o-phenylenediamine, enabling the development of a spectrophotometric method to detect and quantify hydrogen peroxide in milk. The method was validated according to the validation protocols. The analytical curve (8.97–112.16 µmol L−1) for UHT (Ultra High Temperature) whole milk showed a good linear fit. The limits of detection and quantification were 2.96 µmol L−1 and 9.89 µmol L−1, respectively. The method demonstrated an accuracy ranging from 85.1 % to 102.8 %, with a repeatability of ≤ 3.9 % and an intermediate precision of ≤ 7.5 %. The method proved its effectiveness on various types of milk and was compared with other conventional methods traditionally applied to milk analysis. The novelty of the method lies in the use of FeNPs synthesized through a bioinspired process using plant extract, employed for the first time in the detection of H2O2 in milk, a highly complex matrix. The advantages of the analytical method include the use of a small sample and reagent volumes. The ecological aspects of the developed procedure were evaluated using the Analytical Eco-scale protocols, resulting in a score of 77, classified as an excellent green analysis, confirming it as an environmentally friendly method.