Patent ID: 6130037
Filing Date: 2000-10-10
Classification: B01J,C12Q,C40B,G01N,Y10S

Abstract:
A biosensor apparatus for detecting a binding event between a ligand and ligand-binding receptor, comprisingan electrode substrate having a detection surface,formed on said detection surface, a monolayer composed of hydrocarbon chains anchored at their proximal ends to the detection surface;also anchored to the detection surface, a heterodimer-subunit complex composed of first and second peptides that together form an .alpha.-helical coiled-coil heterodimer, and said ligand, where(i) said first peptide is covalently bound to the detection surface, at surface sites distinct from those at which the-hydrocarbon chains are anchored,(ii) said ligand is covalently attached to the second peptide,(iii) said hydrocarbon chains are sufficiently close-packed and ordered such that binding of the second peptide to the first peptide, to form said heterodimer-subunit complex, is effective to measurably reduce the electron flow across the monolayer mediated by a redox ion species in an aqueous medium, relative to electron flow observed in the presence of the first peptide alone, and(iv) binding of the ligand-binding receptor to the ligand is effective to measurably increase the electron flow across the monolayer mediated by said redox ion species,a wall structure cooperating with said substrate to define a chamber for holding the aqueous medium of the redox ion species in contact with said monolayer,means for introducing the ligand-binding receptor into said chamber, andmeans for measuring said redox ion-mediated electron flow across said monolayer, in response to said binding event occurring between said ligand-binding receptor and ligand.