Reusable 3D-printed microfluidic-on-fabric with modular electrodes for point-of-care Na⁺ and K⁺ detection in various biofluids.

) = 1.6 mM). The sensor platform was successfully implemented to detect Na⁺ and K⁺ in a range of biofluids, including urine, saliva, and sweat, with results validated by ion chromatographic methods. An Arduino board (~ $20) was programmed to couple to the sensor for data collection, transducing, processing, and transferring to a computer. Overall, this is a new sensor platform that is low-cost, reusable, modular, and customizable, representing an advancement in POC sensor development.