Detection of Receptor-Ligand Interactions with an GHz Impedance Biosensor System

Nanogap impedance biosensors with electrode separation of 75 nm have been used for the specific detection of biological interactions. Different model systems, such as thrombin -anti-thrombin antibody, and Rev-peptide -anti-Rev aptamer are presented. In order to improve the signal-to-noise ratio the use of reference sensors has been explored. The interaction of prostate specific antigen (PSA) to an anti-PSA antibody is shown to demonstrate the detection at concentrations as low as 10 nM.