When working with a few molecules, the existing protein sequencing technologies lack the single-site amino acid (AA) precision required to detect abnormalities that escape genome analysis. We offer a new method for identifying AAs and short polypeptides using the signal from the surface potential and capacitance obtained from Field Effect Transistor (FET) sensors. Using a combination of the Site-binding and Gouy-Chapman-Stern (GCS) models, we found the signatures of every single AA and polypeptides. These fingerprints are based on orthogonal features such as the proton dissociation constants of each AA’s charging sites, the dielectric constant, and the effective length.
