| CPC G01N 27/4145 (2013.01) [H10K 85/761 (2023.02)] | 18 Claims | 

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               1. A biological field-effect transistor (BioFET) associated with detecting a presence of an analyte in an environment, the BioFET comprising: 
            source and drain regions formed in a substrate; 
                an insulating layer disposed on a surface of the substrate; 
                a gate disposed on the insulating layer and configured to control a current between the source and drain regions; 
                a well region containing an electrolyte solution configured to retain the analyte; 
                a three-dimensional (3D) graphene layer forming a channel region within the well region between the source and drain regions, the 3D graphene layer biofunctionalized with a biological material configured to change an electric charge distribution of the 3D graphene layer in response to the biological material selectively binding with the analyte; and 
                a passivation layer configured to prevent the electrolyte solution from contacting the source and drain regions, wherein the selective binding of the analyte to the biological material is associated with a change in one or more of a current flow, a conductivity, or an impedance of the 3D graphene layer. 
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