Flexible and Printed Potentiometric pH Sensor for Water Quality Monitoring

This work presents a flexible potentiometric pH sensor consisting of a graphite-CuO sensitive electrode and an Ag/AgCl reference electrode. The pH sensor was fabricated by using a simple stencil hand printing technique at room temperature. The results demonstrate that the flexible printed graphite-CuO based pH sensor exhibits a linear response in a wide range of pH 4 to 10.5 with the sensitivity of 22.60 ± 1.3 mV/pH and a response time of 5 s. The developed flexible and miniaturized pH sensor is stable in the water for a long time (more than 1 month) and can be used for online water quality monitoring.