Charge dynamics of amino acids fingerprints and the effect of density on FinFET-based Electrolyte-gated sensor

Abstract

This work presents the charge dynamics and the effect of the density of amino acids on a sensing surface with the help of analytical modelling. We have implemented an in-house simulator incorporating the Gouy-Chapman-Stern and Site-Binding model to capture the perturbations in the proton affinity of reactive sites with the variation of amino acid density over a sensing surface. The results of the models are explained for Alanine, Glutamic Acid and Histidine with their α-carboxylic terminal immobilized on the sensor surface. The results show that an increase in amino acid density on the sensing surface over a certain limit deviates the fingerprints of the proton affinity away from the affinity of the reactive sites of individual amino acids. The effect of different electrolyte concentrations on steric hindrance is also captured for Alanine and Glutamic Acid. Finally, we used a junctionless FinFET to model unique signatures of amino acids down to a single molecule.