Multi-array, multi-specific electrochemiluminescence testing

An instrument for detection or quantification of an analyte by electrochemiluminescence over a broad range of concentrations from 10−12 M to 10−3 M, comprising:

• (a) a support including a dry reagent thereon, and a plurality of electrodes each comprising a composite containing a matrix and a multiplicity of carbon particles dispersed therein, wherein each of said plurality of electrodes
• (i) comprises at least two discrete binding domains,
• (ii) comprises one or more binding reagents affixed to said electrode, said binding reagents being capable of binding a component of a binding electrochemiluminescence assay, wherein said binding reagents in each of said discrete binding domains recognize said analyte but have different binding affinity for said analyte, and
• (iii) is individually addressable;
• (b) a voltage source to supply an electric potential to said plurality of electrodes;
• (c) one or more light detectors capable of detecting or quantifying light emitted from each of said at least two discrete binding domains on said electrodes;
• and
• (d) a microprocessor for detecting or quantifying said analyte based on information received from said one or more light detectors.