Wearable Self‐Powered Smart Sensors Enabled by 2D Flower‐Like Ni–Co Layered Double Hydroxides for Copper Monitoring in Sweat

Abstract The growing power demands of wearable electronic devices have stimulated the development of self‐powered systems in noninvasive healthcare. Herein, ultrathin homogeneous 2D flower‐like nickel–cobalt layered double hydroxide (Ni–Co LDH) nanocomposites are prepared by a one‐step hydrothermal method to integrate a self‐powered system for wearable sweat copper ions (Cu ²⁺ ) monitoring. The Ni–Co LDH nanocomposites with a lamellar structure and numerous active sites, exhibit sensitive selectivity and low detection limits for Cu ²⁺ . In addition, the optimized Ni–Co LDH provides favorable capacitive characteristics as supercapacitors for self‐powering sensors, ensuring continuous sensing energy sources. By connecting wirelessly to a smart device, a self‐powered system is constructed to achieve wearable sensing of Cu ²⁺ in the practical application of sweat. This simple yet effective strategy provides new opportunities for the development of self‐powering health monitoring sensors, as well as smartsensing more heavy metals.