Flexible and high performance Py-rGO/PANI pH sensor for food quality monitoring: a study on chicken meat

Smart packaging systems for food quality monitoring present a promising approach to reduce food waste as well as food-borne diseases. Potentiometric pH sensors offer advantages such as extremely low power consumption, simple operation, and a wide dynamic range, making them one of the most practical sensors for this application. Here, we report on a low-cost fabrication of a polyaniline (PANI) and reduced graphene oxide (rGO) hybrid material. In this process, pyrrole (Py) was used as a green and moderate reducing agent to fabricate a flexible pH sensor (Py-rGO/PANI) with a high specific surface area and excellent stability. The results showed that the Py-rGO/PANI pH sensor demonstrated super-Nernstian pH sensitivity (70.5 mV/pH) and a fast response time (2 s) across a pH range of 4–10. The material exhibited very low drift (0.19 mV/h) and low hysteresis (3.7 mV). Additionally, the sensor showed excellent storage and temperature stability as well as very good selectivity toward interfering ions. Also, the sensor demonstrated excellent accuracy in real-sample testing, with its response closely matching that of a commercial pH meter during direct measurements on chicken meat. The sensor exhibited a stable and linear response under real-sample conditions, confirming its reliability and highlighting its potential for real-time pH monitoring applications in transportation and in-store settings.