Carbon nanotube electrochemical sensor based on and benzofuran derivative as a mediator for the determination of levodopa, acetaminophen, and tryptophan

Abstract

In this research, a (7,8-dihydroxy-3,3,6-trimethyl-3,4-dihydrodibenzo[b,d]furan-1(2H)-one] (DTDF) multi-walled carbon nanotube modified carbon paste electrode was constructed and used as an excellent electrocatalyst in the oxidation of levodopa (LD) in the presence of acetaminophen (AC) and tryptophan (TRP). In the first part of the work, we synthesized DTDF by electrochemically oxidizing the catechol derivative in the presence of dimedone as a nucleophile in an aqueous solution. A modified carbon paste electrode based on this electrosynthesised compound (DTDF) and carbon nanotubes (CNTs) was prepared. Cyclic voltammetry was used to investigate the redox properties of this modified electrode at various scan rates. Next, the mediated oxidation of LD at the modified electrode was described. At the optimum pH of 7.0, the oxidation of LD occurs at a potential about 330 mV less positive than that of an unmodified carbon paste electrode. Based on differential pulse voltammetry (DPV), the oxidation of LD exhibited a dynamic range between 1.0 and 1000.0 μM and a detection limit of 0.46 μM. DPV was used for simultaneous determination of LD, AC, and TRP at the modified electrode and quantitation of LD, AC, and TRP in some real samples by the standard addition method.