Dry Spun, Bulk‐Functionalized rGO Fibers for Textile Integrated Potentiometric Sensors

Abstract Thread or fiber‐based sensors can be integrated into wearable textiles paving the way for re‐engineered electrochemical sensing units for exercise or training analytics in real‐time. Textile‐based sensors currently have limitations such as large diameters, low conductivity, poor electrochemical performance and sensing stability, or expensive manufacturing processes—preventing many commercial applications in sweat sensing. Pure reduced graphene oxide (rGO) fibers show much promise as low‐cost electrode material for the development of high‐performance textile‐based sweat sensing units with strong electrical, mechanical, and material properties, owing to the solid core structure, rather than a coated textile. Potentiometric sensing units based on H+ Ion Selective Electrodes fabricated on dry‐spun rGO and redox modified rGO fibers combined with a rGO fiber‐based reference electrode are reported here. The potentiometric fiber‐based interface is then integrated into a T‐shirt with Bluetooth recording unit for continuous monitoring during exercise. The small diameter and facile functionalization of rGO fibers will enable applications such as multi‐sensor threads and distributed fibers that can be seamlessly integrated into sensing empowered textiles.