GFET Biosensors

 Graphene is one of the most promising biocompatible nanomaterials for point-of-care biomedical applications, such as immunosensor and DNA sensors. In our lab, we developed a graphene-based solution-gated field-effect transistor (GFET) with a unique structure for bio-sensing applications. In this structure, the electrolyteis a common path between the active layer (graphene) and the gate terminal. We investigate the interaction between a non-functionalized graphene layer and liquid biological samples. One of the GFET devices is focused on the measurement of the changes in the electrical properties of human whole blood during the coagulation process. The inserted blood sample works as a common path, through a microchannel containing thromboplastin reagent (tissue factor), between the active layer (graphene) and the gate terminal. This device can be used to detect the prothrombin time working as a point-of-care test.

Electrochemical Sensor

  Electrochemical sensors are molecular sensing devices that intimately couple a biological recognition element to an electrode transducer. Such devices produce an accurate, sensitive, simple, inexpensive, compact, and low-power platform for point-of-care diagnosis. The most common example is a glucose sensor, in this system glucose oxidase is immobilized in the working electrode of an electrochemical cell (3 electrode system) and the current from the oxidation-reduction reaction is detected through cyclic voltammetry, differential pulse voltammetry, amperometry, and various other electrical methods. Our lab is focusing on electrochemical measurements for Recombinase Polymerase Amplification (RPA) assay that is an isothermal DNA amplification technology.