▎ 摘　　要

This paper presents a theoretical analysis for a graphene-based FET real-time detector of the target bacteria E. coli K12. The motivation for this study is to design a sensor device for detection of bacteria in food and water in order to guarantee food safety. Graphene is chosen as our material for sensor design, which has outstanding electrical, physical, and optical performance. In our sensor structure, graphene-based solution gate field effect transistor (FET) is the device model; fabrication and functionalization protocol are presented together in this paper. What is more, a real-time signal display system is the accompanied equipment for our designed biosensor device. In this system, the sensor bias current signal I-ds would change obviously when the target bacteria are attached to the sensor surface. And the bias current I-ds increases when the E. coli concentration increases. In the latter part, a theoretical interpretation of the sensor signal is to explain the bias current I-ds increasing after the E. coli K12 attachment.