La3+-doped Co3O4 Nanoflowers Modified Graphite Screen Printed Electrode for Electrochemical Sensing of Vitamin B6

Abstract

In this study, we combined the advantages of good conductivity, small size, and large surface area and the catalytic property of La3+/Co3O4 nanoflowers to fabricate an electrochemical sensor sensitive to determination of vitamin B6 in real samples. La3+/Co3O4 nanoflowers were synthesized by a co-precipitation method which is a convenient, environment-friendly, inexpensive process. The synthesized nanoflowers were characterized by SEM. A simple and sensitive sensor based on graphite screen printed electrode (GSPE) modified by La3+/Co3O4 nanoflowers was developed for the electrochemical determination of vitamin B6. The electrochemical behavior of vitamin B6 was studied in 0.1 M phosphate buffer solution (PBS) using cyclic voltammetry (CV), chronoamperometry (CHA) and differential pulse voltammetry (DPV). The modified electrode (La3+/Co3O4NFs/GSPE) showed excellent electrocatalytic activity and remarkable sensitivity towards the oxidation of vitamin B6. The fabricated sensor displayed good operating characteristics including low detection limit, and a wide linear dynamic range for the detection of vitamin B6. Using La3+/Co3O4NFs/GSPE as the working electrode, a linear dynamic range between 1.0 to 600.0 μM and a limit of detection of 0.4 µM were obtained. Finally, reliability and accuracy of the proposed sensor were studied in real samples.