MXene-based high performance microfluidic pH sensors for electronic tongue

The development of the electronic tongue (e -tongue) significantly relies on the monitoring of taste -inducing molecules and ions in solutions. One of the five primary flavors, sourness, has a direct correlation with pH measurement, making it essential for food assessment. However, real-time food evaluation is constrained by the high cost and limited portability of conventional taste sensors. Ti3C2 MXene is remarkable in the field of twodimensional (2D) materials for its abundance of functional groups and metallic conductivity. These characteristics contribute to its enormous potential as a material for the fabrication of taste sensors with high sensitivity. This study presents the fabrication and application of reliable and reversible pH sensors based on 2D Ti3C2 MXene for the first time. By integrating a microfluidic channel with interdigitated electrodes (IDEs) and a Nafion layer, the sensors exhibit high selectivity for real-time detection of hydronium ions with the MXene channel. Differentiating soft drinks and evaluating the fermentation of Kimchi are demonstrated. Our work on a low-cost, high-performance MXene-based sensor will pave the way for the future of e -tongue development.