Wearable and printable devices for electrolytes sensing

With the development of biotechnology and the miniaturization of sensors, wearable devices have attracted extensive attention for real-time and non-invasive health monitoring at the molecular level. Among these, sensors for electrolytes analysis play an essential role in monitoring body physiological functions and metabolic activities. Herein, this review firstly summarizes the recent advances in electrolytes sensing via wearable devices, focusing on the most commonly adopted ion-selective electrodes, optical sensors and sensing platforms for effective body fluid collection and analysis. Innovative strategies based on nanomaterials engineering to achieve biosensing reliability, mechanical robustness as well as biocompatibility are also presented. Moreover, novel printable fabrication approaches to realize integrated wearable sensing systems with desirable compatibility and versatility are introduced. Finally, the challenges for practical applications and the perspectives on accurate and multi-functional sensing based on integrated wearable devices are discussed.