Self-encoding sensor with microspheres

A method of detecting an analyte, said method comprising:

• (a) providing a planar array comprising a population of sensor elements at a density of at least 20,000 sensor elements per 1 mm2, said population of sensor elements comprising different subpopulations of redundant sensor elements, wherein analytes are bound to separate redundant sensor elements in at least one of said subpopulations of sensor elements;
• (b) distinguishing signals generated from said separate redundant sensor elements that are bound to said analytes;
• and
• (c) combining each of the signals distinguished from said separate redundant sensor elements, wherein said signals indicate the presence of said analyte, and wherein said signals comprise optical signals, or non-optical signals generated by the separate redundant sensor elements.