Self-encoding sensor with microspheres

A system for detecting an analyte comprising:

• a planar array comprising a population of sensor elements at a density of at least 20,000 sensor elements per 1 mm2, the 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 the subpopulations of sensor elements;
• a detector system configured to distinguish signals generated from the separate redundant sensor elements that are bound to the analytes;
• and
• a data processor comprising instructions to combine each of the signals distinguished from the separate redundant sensor elements, wherein the signals indicate the presence of the analyte, and wherein the signals comprise optical signals, or non-optical signals generated by the separate redundant sensor elements.