Open AccessA Solid-Contact Reference Electrode Based on Silver/Silver Organic Insoluble Salt for Potentiometric Ion Sensing
Author(s) -
Shiyu Gan,
Chunxian Liao,
Rongfeng Liang,
Sanyang Du,
Lijie Zhong,
Yitian Tang,
Tingting Han,
Yu Bao,
Zhonghui Sun,
Yingming Ma,
Li Niu
Publication year - 2022
Publication title -
acs measurement science au
Language(s) - English
Resource type - Journals
ISSN - 2694-250X
DOI - 10.1021/acsmeasuresciau.2c00036
Subject(s) - potentiometric titration , tetraphenylborate , electrolyte , reference electrode , silver chloride , electrode , materials science , working electrode , vinyl chloride , inorganic chemistry , polymer , chemistry , ion , organic chemistry , composite material , copolymer
Solid-contact ion-selective electrodes are a type of ion measurement devices that have been focused in wearable biotechnology based on the features of miniaturization and integration. However, the solid-contact reference electrodes (SC-REs) remain relatively less focused compared with numerous working (or indicator) electrodes. Most SC-REs in wearable sensors rely on Ag/AgCl reference electrodes with solid electrolytes, for example, the hydrophilic electrolyte salts in polymer matrix, but face the risk of electrolyte leakage. Herein, we report a type of SC-REs based on the silver/silver tetraphenylborate (Ag/AgTPB) organic insoluble electrode. The SC-RE consists of a Ag substrate, a solid contact (AgTPB), and a plasticized poly(vinyl chloride) (PVC) membrane containing the hydrophobic organic salt of tetrabutylammonium tetraphenylborate (TBATPB). The potentiometric measurements demonstrated that the SC-RE of Ag/AgTPB/PVC-TBATPB showed a reproducible standard potential in various electrolytes and disclosed high long-term stability. This SC-RE was further fabricated on a flexible substrate and integrated into all-solid-state wearable potentiometric ion sensor for sweat Cl - monitoring.