▎ 摘　　要

NOVELTY - The sensor has a substrate and a gate, source and drain arranged on the substrate. A graphene channel is provided between the source electrode and the drain electrode. A carbon dot is fixed on the surface of the grid. The width of the graphene channel is provided as 0.2-0.3 millimeter. The length of the graphene channel is provided as 4-8 millimeter. The graphene channel is provided as a single layer of graphene. The gate, source and drain are independently provided with a chromium layer and a gold layer. The chromium layer is located between the substrate and the gold layer. USE - Graphene transistor sensor used in the applications. ADVANTAGE - The graphene transistor sensor is provided to fixe the carbon dot on the surface of the gate electrode of the graphene transistor. The carbon dot is covalently combined with the free glucose in the solution. The interface characteristics of the electric double layer between the transistor and the sample solution through the steric effect are changed. Hence the current in the graphene channel is changed. The possibility to detect trace amounts of glucose in the solution is achieved by detecting the current changes in the channel. The graphene transistor glucose sensor is provided with an operating voltage lower than 1V. The minimum detection limit of glucose is reached till 10-14M. The current of the sensor is changed instantly, and the sensitivity is very high after changing the glucose concentration. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following: (1) a carbon dot; and (2) a method for preparing a graphene transistor sensor. DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the graphene transistor sensor. (Drawing includes non-English language text)