Fabrication of poly(ʟ-Aspartic acid) Layer on graphene nanoplatelets paste electrode for riboflavin sensing

This work portrays the preparation and application of poly(ʟ-ApA) layered graphene nanoplatelets paste electrode (PApA/GNpPE) for the electrochemical study of riboflavin (RF). The morphological features of prepared electrodes were characterized by cyclic voltammetry (CV), field emission scanning electron microscopy, and electrochemical impedance spectroscopy. The electrochemical study of RF was performed using CV and differential pulse voltammetry (DPV) techniques. The electrochemical parameters such as polymerization cycles, preconcentration time and potential, pH, and scan rate were optimized using CV to achieve high sensing performance of the electrode. The redox process of RF involving 2e⁻, 2H⁺ mechanism has also been proposed. The PApA/GNpPE was applied to record the current response using CV and DPV with varied concentrations of RF to evaluate the LOD and it was achieved to be 3.35 × 10⁻⁷ M and 2.29 × 10⁻⁸ M, respectively. With the application of proposed electrode and DPV technique RF pharmaceutical sample and biological fluids were analyzed with adequate recovery.