Simple and sensitive electrochemical analysis of riboflavin at functionalized carbon nanofiber modified carbon nanotube sensor

The present work demonstrates the development of functionalized carbon nanofiber and carbon nanotube composite paste electrode towards the electrochemical analysis of riboflavin (RF) in 0.2 M phosphate buffer solution of pH 7.0 in the presence of ascorbic acid. RF shows the enhanced electrochemical reaction at the modified electrode surface with well-resolved and distinct redox peaks than bare carbon nanotube paste electrode. The material characteristics were analyzed using field emission scanning electron microscopy, X-ray powder diffraction, electrochemical impedance spectroscopy, and cyclic voltammetry methods. The proposed electrode gives a fine linear relation between the concentration of RF and oxidation peak current in the linear range of 5.0–60.0 µM with the limit of detection of 15.35 nM and limit of quantification of 51.18 nM. Also, the sensing capability of the electrode for RF analysis was tested in B-complex capsule with fine recoveries.