Colorimetric detection of H2O2 by peroxidase-like catalyst iron-based nanoparticles synthesized by using hyperaccumulator plant-derived metal solution

H2O2, a by-product of many enzymatic reactions, plays an important role in various fields such as the food industry, cosmetics, textile, electronics, mining, paper, medicine, environmental chemistry, biological analysis, and clinical diagnosis; so, the quantitative detection of it is of great importance. In this work, the iron-based nanoparticles (FeNPs), as a peroxidase-like catalyst for the colorimetric detection of H2O2, were synthesized by using the acidic leaching solution of an iron hyperaccumulator plant, Pinus brutia. The experimental results proved that FeNPs exhibited strong intrinsic peroxidase-like activity and could efficiently catalyze the oxidation of chromogenic substrate 3,3 & PRIME;,5,5 & PRIME;-tetramethylbenzidine (TMB) in the presence of H2O2. The catalytic reaction by FeNPs was in accordance with typical Michaelis-Menten kinetics, which showed that FeNPs possessed a much higher affinity to H2O2 and TMB than horseradish peroxidase (HRP). FeNPs were utilized as a peroxidase-like catalyst for the detection of H2O2 in a relatively wide range of 0.05-0.20 mM with a lower detection limit of 0.05773 & mu;M. In brief, this work reported the first use of iron-based nanoparticles synthesized from a hyperaccumulator plant in the sensitive, selective, and reliable detection of H2O2, which may promote the development of new peroxidase-like nanocatalysts for colorimetric detection applications.