Devices and methods utilizing arrays of structures for analyte capture

An analytical device for determining the presence or an amount of an analyte in a test sample comprising, in combination:

• a base layer;
• an inlet port and a vent;
• an array of structures arising from said base layer, each of said structures having a surface providing a capture site for said analyte;
• an immobilized reagent, said immobilized reagent covalently or non-covalently attached to said surface of said structure, said immobilized reagent capable of binding an a member selected from the group comprising:
• analyte, analyte-analog, and an ancillary binding member;
• a plurality of channels adjacent to said structures, wherein said test sample containing said analyte, analyte-analog, or ancillary binding member flows through said channels, said analyte, analyte-analog, or ancillary binding member diffusing across the width of said channels to bind said immobilized reagent;
• and
• a labelled reagent comprising a specific binding member conjugated to a detectable label, said detectable label capable of producing a signal at said capture site, said signal indicating the presence or amount of said analyte present in said test sample, wherein the ratio of the height of said structures to the average width of said channels is greater than 2:1.