Potentiometric Sensors with Polymeric Sensing and Reference Membranes Fully Integrated into a Sample-Wicking Polyester Textile

Responding to current limitations in paper-based sensors and the increased interest in wearable sensors, we introduce here potentiometric sensors fully integrated into a knitted polyester fabric and their application in aqueous and biological samples. Single layer ion-sensing devices requiring only 30 μL of sample were fabricated using wax patterning and Ag/AgCl paint. These devices give a Nernstian response to chloride over 4 orders of magnitude – an order of magnitude improvement from analogous paper-based devices. We also report the penetration of polyester yarns with polymeric hydrophobic and hydrophilic ion-sensing and reference membranes, all fully embedded within the fabric. These results demonstrate the promise of knitted fabrics as substrates for fully-integrated potentiometric sensors with improved detection limits. They also elucidate the effect of pore structure on sensor fabrication and performance, thereby affecting how we understand both fabric- and paper-based devices.