Development of a Dy2O3@Eu2O3-carbon nanofiber based electrode for highly sensitive detection of papaverine

A sensitive electrochemical method based on carbon nanofibers (CNFs) and bimetallic nanoparticles of dysprosium oxide (Dy2O3) and europium oxide (Eu2O3) was developed for the determination of papaverine in pharmaceuticals and human urine. Several electrodes were compared in respect to their electrochemically active surface area calculated as 0.0603, 0.1300, 0.3440, 0.3740 and 0.4990 cm(2) for bare GCE, CNFs/GCE, Eu2O3-CNFs/GCE, Dy2O3-CNFs/GCE and Dy2O3@Eu2O3-CNFs/GCE, respectively. Electrodes were also compared in respect to their performance towards the voltammetric process of papaverine. The peak potential (Epa) of papaverine was 1.094 V, 0.993 V, 0.978 V, 0.969 V and 0.966 Vat unmodified GCE, CNFs/GCE, Eu2O3-CNFs/GCE, Dy2O3-CNFs/GCE and Dy2O3@Eu2O3-CNFs/GCE, respectively. This indicated that the oxidation peak potential of papaverine shifted gradually towards the negative potentials and the peak current increased gradually from unmodified GCE to CNFs/GCE, Eu2O3-CNFs/GCE, Dy2O3-CNFs/GCE and Dy2O3@Eu2O3-CNFs/GCE. The influence of experimental parameters such as scan rate and pH on the voltammetry of papaverine was studied. The Dy2O3@Eu2O3-CNFs/GCE system presented a dynamic working range between 1.0 x 10(-7) and 2.0 x 10(-6) M with a detection limit of 1.0 x 10(-8) M for papaverine. The platform (Dy2O3@Eu2O3-CNFs/GCE) exhibited excellent sensitivity and selectivity for papaverine in the presence of uric acid and was successfully applied for determining papaverine in pharmaceuticals and urine samples. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

A sensitive electrochemical method based on carbon nanofibers and bimetallic nanoparticles of dysprosium oxide and europium oxide was developed for the determination of papaverine in pharmaceuticals and human urine. The study compared different electrodes in terms of their electrochemically active surface area and performance towards the voltammetric process of papaverine. The Dy2O3@Eu2O3-CNFs/GCE system showed excellent sensitivity and selectivity for papaverine, with a wide dynamic working range and a low detection limit.