Fabrication and Characterization of a Fully Screen-Printed Ag/AgCl Reference Electrode Using Silica Gel Inks Exhibiting Instantaneous Usability and Long-Term Stability

Abstract

An instantly usable screen-printed Ag/AgCl electrode with long-term stability was fabricated for use as a costeffective disposable reference electrode. A new silica gel-poly(vinylidene difluoride) ink was prepared to form the hydrophilic liquid junction and electrolyte layer of a planar-type reference electrode and the temporal evolution of its open-circuit potential in different electrolyte solutions was subsequently compared to that of a commercial reference electrode. The potential stabilized within 3 min and remained constant over 20 days. The impedance of the liquid junction was~2500 Ω, which is close to the value observed for a commercial reference electrode. These results implied that the as-fabricated reference electrode was well-suited for practical measurements.

Liquid Metal Fiber Mat as a Highly Stable Solid-State Junction for Inkjet-Printed Flexible Reference Electrodes

“…(2018) mixed TritonX, PVDF, DMPU, and silica gel to prepare liquid junction ink. The potential drift of the prepared RE was no more than 0.2 mV/h, and the long-term stability could reach 505 h. 21 Ichimura et al (2021) used 10 wt % polyurethane in 1-methyl-2-pyrrolidinone to form liquid junction ink, and the potential drift rate is up to 4 mV/h. 22 Gallium (Ga) is an active metal that is easily oxidized to gallium oxide (Ga 2 O 3 ) in air.…”