Determination of acetaminophen using a glassy carbon electrode modified by horseradish peroxidase trapped in MWCNTs/silica sol-gel matrix

A new and easy to fabricate voltammetric biosensor for acetaminophen determination was developed based on horseradish peroxidase (HRP) trapped between silica sol-gel film and multi-walled carbon nanotubes on glassy carbon electrode. Acetaminophen determinations were carried out in presence of H2O2 as enzyme activator. The modified electrode showed excellent electrocatalytic activity and rapid response to acetaminophen in the presence of H2O2 as enzyme activator. Various parameters influencing the biosensor performance such as amount of enzyme, H2O2 concentration, potential scan rate and pH have been investigated. Under the optimal conditions, a wide linear range of 1.85×10−6 to 2.7×10−3 M for acetaminophen determination was obtained. Limit of detection was calculated about 18 nM and sensitivity was about 220 nA/µM. Furthermore, the proposed biosensor was successfully examined for simultaneous determination of acetaminophen with uric acid (UA) and folic acid (FA) as prevalent interferes. The proposed biosensor showed satisfactory stability for 3 weeks and applicability of developed biosensor was confirmed with accurately evaluation of acetaminophen in real samples such as urine and tablet.