Fabrication of graphene FETs combined with fluorescence and its Double Read-Out System

Based on the fact that graphene films grown by Chemical Vapor Deposition (CVD) have unique electronic and optical properties concurrently, a Graphene Field-Effect Transistor (GFET) which combined electronics and fluorescence was proposed and fabricated in this work. Comparing conventional GFETs, fluorescent probes were dissolved in the electrolyte of GFETs. Consequently, the combined GFETs could not only be detected by common electrical method but also be detected by fluorescent method. A Double Read-Out System (DROS) was constructed to monitor the combined GFETs by electrical method and fluorescent method synchronously. The combined GFETs and DROS have been evaluated by sensing pH value of a Phosphate Buffered Solution (PBS). Both the electrical signal and the fluorescence intensity of the combined GFETs were recorded in real-time and synchronously. Through data processing, the combined effect of electrical signal and fluorescence intensity lead to a combined sensitivity that is higher than each isolate method. These results may provide a new feasible direction for CVD graphene FETs research. (C) 2015 Elsevier B.V. All rights reserved.