In this paper, we describe a new simulation methodology and analytical results, which are disruptive because in addition to provide enough resolution to distinguish different AAs, our new method is also able to read the signal from small polypeptides to discover mutations and provide information on the sequence. This could avoid having to degrade the whole peptide and provide a methodology similar to shotgun MS. Using a site-binding theory for the electrochemical response of FETs, we discuss for the first time, the signatures that appear in the surface potential or surface capacitance from a single amino acid immobilized on the surface of FET sensors. We discuss the experimental conditions required to resolve the electrical signal in terms of electrical and chemical noise. We suggest new fabrication strategies that bring AA recognition to a new level with the current state-of-the-art technologies (e.g., pure 2D materials and FETs with high-K dielectrics ).