A novel electrochemical acetaminophen sensor based on multiwalled carbon nanotube and poly(neutral red) modified electrodes with electropolymerization in ternary deep eutectic solvents
Xizhen Liang, Yueming Zhou, Joseany M.S. Almeida, Christopher M. A. Brett
Abstract
A new electrochemical sensor based on a neutral red (NR) and multiwalled carbon nanotubes (CNT) modified glassy carbon electrode (GCE) with NR electropolymerized in ternary deep eutectic solvents (DES), has been developed. Cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy were used to characterize the performance of the sensor. Differential pulse voltammetry was utilized to evaluate the analytical performance of acetaminophen (APAP) oxidation on the modified electrode (PNR/CNT/GCE) in Britton-Robinson buffer aqueous solution. The combined use of PNR prepared by electropolymerization in novel green DES on CNT led to a large electroactive surface area and a synergistic effect attributed to π–π electronic interactions and resulted in improved performance towards APAP detection, with a high sensitivity (56.4 µA µM−1 cm−2) in the range 2.0–70 µM and a low limit of detection (0.015 µM). The constructed sensor displayed outstanding selectivity to detect APAP in the presence of dopamine, and good repeatability, reproducibility and stability. The sensor was successfully applied to the determination of APAP in pharmaceutical samples, with good recoveries.