Deriving a novel methodology for nano-BioFETs and analysing the effect of high-k oxides on the amino-acids sensing application

•The Gouy-Chapman-Stern layer model combines the Helmholtz and the diffuse double layer of the Gouy-Chapman model to explain the development of the double-layer capacitance on the sensor’s surface.•The Site-binding model is used to describe the surface charge developed at the oxide/electrolyte interface.•This paper presents a new methodology that combines these two theories, and our new method is applied to AAs (amino acids) immobilized on the sensor surface.•Moreover, our simulation work shows that each AA has a unique signature (fingerprints) that can be used to distinguish and identify each AA.