Publication

Abstract : Caffeine detection is essential for maintaining the food quality standards and for facilitating real-time exposure assessment, particularly amid growing interest in non-invasive health monitoring. Herein, a selective electrochemical platform for caffeine detection based on a novel silver selenide – mesoporous graphitic carbon nitride (Ag2Se-MGCN) nanointerface for the first time. The Ag2Se-MGCN was synthesized via a hydrothermal method and utilized as a nanointerface on a screen-printed carbon electrode (SPE) for Caffeine detection. The sensor exhibited concentration-dependent oxidation behaviour with two distinct linear ranges: 0.5 µM – 100 µM and 100 µM – 1000 µM, with limits of detection (LODs) of 0.023 µM and 63 µM, respectively. The enhanced electrocatalytic activity of Ag2Se-MGCN nanointerface towards caffeine oxidation is due to synergistic electronic interactions and interfacial charge transfer. In the presence of a ten-fold excess of interfering species, the sensor showed a stable caffeine oxidation response, along with good repeatability, reproducibility, and stability. Recovery values for tea, coffee, and artificial sweat samples ranged from 97 to 103%, with RSDs below 3%, highlighting the reproducibility of the sensor. The electrocatalytic oxidation, facilitated by the synergistic interaction between Ag2Se and the MGCN framework, provides a promising nanointerface for real-time sensing of caffeine in complex biological and beverage matrices.