Apparent pH sensitivity of solution-gated graphene transistors. Issue 17 (7th April 2015)

• Record Type: Journal Article
• Authors: Lee, Moo Hyung; Kim, Beom Joon; Lee, Keun Hyung; Shin, Ik-Soo; Huh, Wansoo; Cho, Jeong Ho; Kang, Moon Sung
• Is Part Of: Nanoscale. Volume 7:Issue 17(2015)
• Page Start: 7540
• Page End: 7544
• Publication Date: 2015-04-07
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr00414d
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Importance of ionic strength in determining the pH response of solution-gated graphene transistors is highlighted. Abstract : Solution-gated graphene transistors were developed recently for use in pH sensor applications. The device operation is understood to rely on the capability of hydronium and hydroxide ions in solution to change the electrical properties of graphene. However, hydronium and hydroxide ions are accompanied by other ionic species in a typical acidic or basic solution and, therefore, the roles of these other ionic species must be also considered to fully understand the pH response of such devices. Using series of pH buffer solutions designed carefully, we verified that the magnitude and even the direction of pH-dependent Dirac voltage ( V Dirac ) shift (the typical pH sensing indicator) depend strongly on the concentration and composition of the buffers used. The results indicate that the interpretation of the apparent pH-dependent V Dirac response of a solution-gated graphene transistor must include the contributions of the additional ions in the solution.