Integrated pH Sensors Based on RuO<sub>2</sub>/GO Nanocomposites Fabricated Using the Aerosol Jet Printing Method
Mahtab Taheri, Mohsen Ketabi, Ahmad Al Shboul, Shirin Mahinnezhad, Ricardo Izquierdo, M. Jamal Deen
Abstract
High Resolution Image Download MS PowerPoint Slide An aerosol jet printing (AJP) process for depositing ruthenium dioxide (RuO 2 ) as a promising material for pH sensing is reported. Graphene oxide (GO) with a large surface area was used for the in situ sol–gel deposition of RuO 2 nanoparticles on its surface. The cosolvent ratio and solid loading of the solution are adjusted to form a printable and stable ink. The monodispersed aerosol was atomized on the surface of the screen-printed carbon electrode in order to develop an integrated pH sensor. The RuO 2 –GO pH sensor demonstrates excellent performance, with a rapid response time of less than 5 s and high sensitivity in the pH range of 4–10. Compared to traditional carbon electrodes, the RuO 2 –GO sensor shows up to four times higher sensitivity. The increased sensitivity is a result of the consistent attachment of small-crystallized RuO 2 nanoparticles onto the surface of GO sheets, leading to a synergistic effect. Thanks to the AJP method as a facile and cost-effective integration technique, the fabricated electrodes can serve as an alternative to traditional rigid pH electrodes for accurate pH measurement.