Preparation of nanopillar array electrode of iridium oxide for high performance of pH sensor and its real‐time sweat monitoring

Abstract

AbstractA highly sensitive potentiometric pH sensor was developed based on nanopillar array electrodes of iridium oxide. The as‐prepared pH sensor exhibited a high pH sensitivity (69.43 mV/pH), fast response time (8.1 s), and good durability (0.76 mV/h). The sensing performance of the pH sensor was maintained under mechanical bending and even after 1000 repetitive bending/releasing cycles. As a proof‐of‐concept, a wearable headband sensor was fabricated by integrating the pH sensor with a wireless electronic module based on a printed circuit board. The on‐body test indicated that the wearable pH sensor provides reliable and stable data in the real‐time monitoring of pH changes in human sweat during stationary indoor cycling. The pH sensors based on nanopillar array electrodes of iridium oxide have great potential in many portable or wearable applications in healthcare systems, non‐invasive diagnostics, environmental analysis, and food sensors.