Graphene-based ion-sensitive field effect transistor

Abstract

Graphene has drawn a huge research interest in chemical and biological sensor applications, since its first discovery in 2004, primarily due to its high surface to volume ratio, high carrier mobility and unsaturated sp <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> bonds at the surface. Although many different graphene-based chemical sensors have been reported, its application in biological sensors is quite limited so far. Nonetheless, graphene-based field effect transistors (FETs) offer an excellent platform to develop biological sensors capable of performing detection of bio-analytes in liquid media, including sensing various types of ions with applications in drug discovery and cell efflux research. Particularly potassium ion sensing is important for prediction of the onset of heart attack and epilepsy. In this work, we propose a graphene-based top-gated field effect transistor on two different substrates, with an ion-selective membrane coating on the graphene, to realize a highly sensitive and selective K <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">+</sup> ion sensor.