Vertically aligned gold nanowires as stretchable and wearable epidermal ion-selective electrode for noninvasive multiplexed sweat analysis

Qingfeng Zhai, Lim Wei Yap, Ren Wang, Shu Gong, Zhirui Guo, Yiyi Liu, Quanxia Lyu, Joseph Wang, George P. Simon, Wenlong Cheng

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6 Citations (Scopus)


The noninvasive continuous analysis of human sweat is of great significance for improved healthcare diagnostics and treatment in the future, for which a wearable potentiometry-based ion-selective electrode (ISE) has attracted increasing attention, particularly involving ion detection. Note that traditional solid-state ISE electrodes are rigid ion-to-electron transducers that are not conformal to soft human skin and cannot function under stretched states. Here, we demonstrated that vertically aligned mushroom-like gold nanowires (v-AuNW) could serve as stretchable and wearable ion-to-electron transducers for multiplexed, in situ potentiometric analysis of pH, Na+, and K+ in sweat. By modifying v-AuNW electrodes with polyaniline, Na ionophore X, and a valinomycin-based selective membrane, we could specifically detect pH, Na+, and K+, respectively, with high selectivity, reproducibility, and stability. Importantly, the electrochemical performance could be maintained even under 30% strain and during stretch-release cycles without the need of extrinsic structural design. Furthermore, our stretchable v-AuNW ISEs could be seamlessly integrated with a flexible printed circuit board, enabling wireless on-body detection of pH, Na+, and K+ with fast response and negligible cross-talk, indicating considerable promise for noninvasive wearable sweat analysis.

Original languageEnglish
Pages (from-to)4647-4655
Number of pages9
JournalAnalytical Chemistry
Issue number6
Publication statusPublished - 17 Mar 2020

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