A novel flexible Ag/AgCl quasi-reference electrode based on silver nanowires toward ultracomfortable electrophysiology and sensitive electrochemical glucose detection
Jing Sun, Qingxiang Wang, Gang Luo, Weichen Meng, Meng Cao, Yanzhao Li, Michael Masterman‐Smith, Haibo Yang, Xudong Sun, Ming‐Fei Lang
Abstract
To miniaturize or integrate electrochemical devices, new types of nanoparticle-based Ag/AgCl quasi-reference electrodes (qREs) have been generated via screen printing and inkjet printing. However, their nanostructures and addition of binder materials produce unsatisfactory conductivity and sensitivity. Herein, a novel Ag/AgCl qRE with a nanowire-and-nanoparticle (NWP) structure is developed. The unique NWP-Ag/AgCl qRE is first generated by drop coating silver nanowires (AgNWs) on poly(dimethylsiloxane) (PDMS), followed by chemical chlorination. Because the nanowires form well-connected network, the novel NWP-Ag/AgCl qRE creates efficient charge transport paths as well as porous 3D structures that enable faster electrolyte percolation. The NWP-Ag/AgCl qRE reaches 95% stable potential fast (6.4 s) and is extremely stable (at least 8000 s continuous measurement and 6-month shelf life). The NWP-Ag/AgCl qRE on PDMS provides ultracomfortable tactile experience that is suitable for skin-contact electrophysiology. The NWP-Ag/AgCl qRE has also been successfully applied to the detection of glucose with a linear range of 1 μM–1900 μM. This study establishes a new printer-free Ag/AgCl qRE fabrication method with simple chemistry. Furthermore, the new method is a truly transformatively efficient and cost-effective approach with substantial industrial applications to electrophysiology and electrochemical device-making.