Identification of the amount of binding sites and dissociation constants of a ligand-receptor complex using AlGaN/GaN high electron mobility transistors

Ligand-receptor binding site model and the operational model for the depletion mode field-effect-transistors (FETs) are incorporated together for the transistor-based sensors to elucidate the binding affinity between ligands and receptors. AlGaN/GaN high electron mobility transistors (HEMTs) were immobilized with antibodies to detect a short peptide consisting of 20 amino acids. The drain current change of the transistor caused by ligand-receptor binding was regarded as signals and fitted into the binding-site models for analysis of binding affinity. The dissociation constants of the ligand-receptor pairs and the number of binding sites on receptors were revealed form the analysis. The results are very consistent to data reported by other methods from literature. The incorporation of the HEMTs and the binding-site models is demonstrated to be useful for studying the binding affinity between ligands and receptors.