Poly(Patton and Reeder's reagent) modified carbon paste electrode for the sensitive detection of acetaminophen in biological fluid and pharmaceutical formulations.

An electrochemical sensor for sensitive detection of acetaminophen (AAP) was developed by electropolymerizing Patton and Reeder's reagent at carbon paste electrode (CPE). Modification improves the redox kinetics of AAP with increased current sensitivity. A similar modification at multiwall carbon nanotube (MWCNT) modified CPE did not result in an impressive charge transfer. Electrochemical impedance spectroscopy (EIS) of the bare and modified electrodes investigated imply a least charge transfer resistance at Patton and Reeder's reagent modified carbon paste electrode (MCPE/PR) as compared to bare CPE and MWCNT modified electrode. Differential pulse voltammetric (DPV) study at MCPE/PR electrode did not suffer any interference from its hydrolytic degradation product 4-aminophenol (4-AP) even in 1000-fold excess of its concentration and enables its detection simultaneously. A linear dynamic range of 0.7-100 μM with detection limit (S/N=3) of 0.53 μM was obtained for AAP. This modified electrode is easy to prepare, cheap, and having good reproducibility and stability. The analytical performance of the modified electrode is assessed by successfully applying it for the estimation of acetaminophen in different pharmaceutical samples and spiked biological fluid.