A method for manufacturing a biological field-effect transistor (BioFET) is disclosed. In some implementations, the method may include preparing a carbonaceous dispersion by adding a three-dimensional (3D) graphene into a solvent; depositing the carbonaceous dispersion onto a p-type silicon wafer; spin-coating a positive photoresist over the carbonaceous dispersion; forming source and drain terminals on the p-type silicon wafer, the source and drain terminals in contact with the 3D graphene of the carbonaceous dispersion; removing residual photoresist from the carbonaceous dispersion by placing the p-type silicon wafer in 1-methyl-2-pyrrolidone (NMP); and biofunctionalizing the carbonaceous dispersion with a molecular recognition element configured to alter one or more electrical properties of the Bio-FET in response to exposure of the molecular recognition element to the analyte.