Electrochemical sentinels: freestanding MnOx–laser-induced graphene electrodes for sensitive fenitrothion monitoring in food

A freestanding manganese oxide nanoparticle–decorated laser-induced graphene electrode (MnOx-LIGE) for sensitive electrochemical detection of the organophosphate insecticide fenitrothion (FT) is reported. The electrode is fabricated via a one-step laser-engraving process on MnCl₂-doped polyimide films, enabling the simultaneous formation of porous graphene and in situ decoration with MnOx nanoparticles. Structural characterization confirms a three-dimensional porous graphene network uniformly decorated with MnOx nanoparticles, providing abundant active sites and accelerated electron transfer. Benefiting from this architecture, the MnOx-LIGE exhibits a wide linear detection range from 100.0 nmol/L to 250.0 µmol/L with a low detection limit of 13.66 nmol/L. Integrated with a portable electrochemical workstation, the sensor demonstrates excellent selectivity and stability. It achieves reliable recoveries of 102.4–104.2% in mango samples, highlighting its potential for rapid on-site monitoring of pesticide residues. Section Graphical