Patent ID: 7157234
Filing Date: 2007-01-02
Classification: G01N

Abstract:
1. A binding assay for sensing analyte mass in a liquid sample, comprising: a) immobilizing an array on a surface of a substrate, wherein the array comprises a plurality of microscopic sorbent zones, wherein a microscopic sorbent zone comprises a multi-layer matrix of an analyte binding partner, the matrix extending up to 200 nm vertically from the surface of the substrate; b) contacting a defined volume of sample believed to contain an analyte with at least one microscopic sorbent zone, the analyte binding partner in the microscopic sorbent zone being present in excess relative to the analyte, so that any analyte present in the defined volume is substantially depleted from the sample and concentrated on the microscopic sorbent zone to form an analyte capture complex with the analyte binding partner; c) tagging the analyte capture complex with a fluorescent label; d) illuminating the microscopic sorbent zone with a laser in the absence of liquid; and e) detecting fluorescence emissions from any microscopic sorbent zone having an analyte capture complex tagged with a fluorescent label, thereby determining the analyte mass harvested from the defined volume of sample, wherein said analyte mass is determined from a dose response curve.