Internally referenced competitive assays

A device for the detection of at least one analyte in a sample solution, comprising:

• (a) a first member of an inverse ligand-receptor pair attached to a first member of a direct ligand-receptor pair and attached to a signal reagent;
• and
• (b) a solid support having a first and a second signal zone wherein the first signal zone contains a second member of the inverse ligand-receptor pair and the second signal zone contains a second member of the direct ligand-receptor pair, wherein:
• the members of (a) are in fluid communication with the members of (b) and the total amount of the first member of an inverse ligand-receptor pair in a population of particles is such that from one to three predetermined concentrations of an analyte can be discerned from a signal ratios, the first concentration indicated when the ratio between the first and second signal zones is or approaches infinity, the second concentration when the ratio between the first and second signal zone is approximately one, and the third concentration indicated when the ratio between the first and second signal zones is approximately the inverse of infinity.