Flexible chemiresistive sensor with xurographically patterned gold leaf as contact electrodes for measuring free chlorine

Free chlorine is commonly used for disinfecting water for various purposes including drinking water, recreational water etc. The free chlorine concentration should remain within a range of 0.5 -2 ppm for an effective disinfection specially for drinking water. Therefore, a low-cost sensor is required to measure free chlorine concentration at different position of the water distribution channels to ensure safe and healthy water for public. Here, we demonstrate a low cost, flexible and solid state chemiresistive sensor fabricated on a Kapton tape with Graphene like Carbon as the sensing film and xurographically patterned gold leaf as the contact electrode. The fabrication process is simple, quick and robust to manufacture reproducible electrodes. The chemiresistive sensor was able to measure free chlorine concentration from 0.05 -1.75 ppm.