Electrochemical detection of gallic acid in commercial beverages empowered by the use of paper-based tool to collect and analyze

A simple and innovative paper-assisted electrochemical approach was developed for the determination and temporal monitoring of gallic acid in commercial beverages. The proposed platform combines low-cost screen-printed electrodes with wax-patterned paper discs, enabling the paper substrate to act simultaneously as a sample collector and analyzer. Just using very simple and mass-scalable approaches, limits of detection and quantification of 0.4 and 1.3 μM were obtained, respectively. The portable device was successfully applied toward commercial green tea and peach juice, demonstrating satisfactory application in both diluted and undiluted matrices. The electrochemical results showed good agreement with the gold-standard chromatographic protocol, with accuracy values comprised between 90 and 105%. The ultimate platform offered an effective compromise between analytical performance, simplicity, low sample consumption, and reduced cost, and it was successfully applied toward the evaluation of the storage of the tested beverages, highlighting a good suitability in food control.