Electroanalysis of phenylalanine in food supplement by differential pulse voltammetry technique: Application of economical and handmade Sonogel-Carbon electrodes improved with a fast polarization step

• Handmade carbon ceramic electrodes were applied in the determination of phenylalanine. • Fast and eco-friendly synthesis procedure led to effective sensor devices. • Each electrode cost only 0.15 € and exhibit excellent renewability. • No modification of the device was required in contrast to previously reported devices. • Analysis of phenylalanine in a food supplement sample was successfully carried out. Sonogel-Carbon electrodes have been applied successfully in the determination of phenylalanine (Phe). These handmade economical sensor devices exhibit better electroanalytical performance than commercial electrodes, and by a fast surface polarization step the electrochemical signal was significantly increased. Improvements in the electrochemically active surface area and electrical conductivity were demonstrated. Excellent figures of merits were assessed, such as a sensitivity value of 68.19 ± 3.11 µA mM −1 cm −2 comparable to other previously reported devices and limit of detection of 31.92 ± 3.75 µM. Sonogel-Carbon electrodes exhibit worthy selectivity in the presence of other amino acids and electroactive species. Finally, satisfactory recovery values between 96 and 101 % were obtained when this material was applied in the determination of Phe in a food supplement sample. Sonogel-Carbon electrodes stand out compared to other reported sensor devices due to their simple, low-cost and eco-friendly manufacturing; their reusability; and their robust and selective electrochemical performance.