Study of protein-peptide binding affinity using AlGaN/GaN high electron mobility transistors

Antibody-immobilized AlGaN/GaN high electron mobility transistors (HEMTs) were used for detecting peptides and revealing the number of binding sites of the antibody and the dissociation constants. Two binding sites were found on this antibody for the peptide and the dissociation constants of the antibody-peptide complex were extracted from a two-binding-site model. The estimated dissociation constants are consistent with the detection limit of the sensor showing the important role of the dissociation constants in the performance of the sensors. The results demonstrate that the AlGaN/GaN HEMTs cannot only be used for biosensors, but also can be used for the biological affinity study. © The Electrochemical Society.