Mechanochemistry Reaches-Out Sensing: Peroxidase-Mimic Fe-BTC MOF for Hydrogen Peroxide Detection by a Solvent-Free Synthesis

A low-cost enzyme-mimic iron(III) trimesate MOF, prepared by a novel and green mechanochemical synthetic protocol, is used for the excellent colorimetric detection of hydrogen peroxide (H₂O₂). The developed iron(III) trimesate MOF, solvent-free mechanochemically synthesized under mild conditions and in a very short time (from 6 to 60 min), is an exciting potential candidate for H₂O₂ detection, avoiding the immobilization of additional peroxidase enzymes. The influence of pH, temperature, catalyst concentration, and incubation time on iron(III) trimesate MOF peroxidase-mimic activity was investigated, showing a lower limit of detection (0.24 μM) and a wider linear range (7.5-75 μM) than other peroxidase-like inorganic materials typically used for colorimetric sensing. The superior catalytic properties of our material with respect to the current literature can be ascribed to the presence of defects in the MOF structure due to the milling synthesis process.