Design of a Boron-Doped Diamond Microcell Grafted with HRP for the Sensitive and Selective Detection of Ochratoxin A

Ochratoxin A (OTA) is considered the most toxic member of ochratoxin group. Herein, a novel label-free electrochemical sensor based on horseradish peroxidase (HRP) enzyme developed for OTA detection. The HRP was covalently immobilized working electrode planar boron-doped diamond (BDD) microcell previously covered with diazonium film and grafted single-walled carbon nanotubes (SWCNTs). Each surface modification step evaluated by cyclic voltammetry scanning electron microscopy. Square wave used detection OTA. linear range biosensors ranged between 10−14 0.1 M, limit (LOD) 10 fM, an RSD equal to 5%, sensitivity 0.8 µA per decade. In addition, showed good selectivity in presence analogs; it validated samples such as corn, feed, wheat. metrological performance present makes alternative