Combined nanogap nanoparticles nanosensor for electrical detection of biomolecular interactions between polypeptides

A concept for the electrical detection of a biological interaction is proposed, mainly based on the conductance variation of a nanometer size-gap (typically less than 100 nm) between two planar electrodes. A functionalized surface was used in the vicinity of the gap in order to concentrate the ligand/receptor complex between the electrodes. The chemistry chosen for the immobilization of the ligand on the biosensor surface is compatible with peptide structures. The receptor in solution was labeled with gold particles which can be inserted into the gap. A significant conductance variation was observed without having to use a silver enhancer solution in the case of biotin/streptavidin or biotin/antibiotin antibodies model ligand/receptor interactions. (C) 2004 American Institute of Physics.