A Peroxidase-Based Biosensor Supported by Nanoporous Magnetic Silica Microparticles for Acetaminophen Biotransformation and Inhibition Studies

Magnetized nanoporous silica based microparticles (MMPs) were used for horseradish peroxidase (HRP) immobilization and applied for amperometric peroxidase-based biosensor development. A magnetized carbon paste electrode permitted the MMPs attraction. The biosensor was applied to the investigation of the enzymatic oxidation of acetaminophen (paracetamol). The biosensor operated at low applied potential and the signal corresponded to the electroreduction of N-acetylbenzoquinoneimine (NAPQI) generated by the enzyme HRP in the presence of hydrogen peroxide. The biosensor allowed performing the quantitation of acetaminophen in the micromolar concentration range and the comparative study of thiols which inhibited the biosensor response. Distinct inhibition results were observed for HRP entrapped in the silica microparticles compared to the soluble HRP.