A method of detecting the formation of an analyte-biomolecule complex comprising the following steps: providing a planar array of biomolecules comprising a plurality of beads having biomolecules attached thereto, wherein the plurality of beads comprises different bead types, said bead types being distinguishable by said biomolecules and each bead type being associated with a unique chemical or physical characteristic that identifies the biomolecules attached to said bead type, wherein beads are arranged in a planar array and biomolecules attached to said beads are exposed to a contiguous liquid phase, said biomolecules capable of forming complexes with corresponding analyte compounds, when said analyte compounds are present in said liquid phase; contacting the biomolecules with a sample that may contain one or more analyte compounds such that, if the analytes are present in the sample, said analytes bind to corresponding biomolecules to form analyte-biomolecule complexes; detecting the formation of the analyte-biomolecule complexes; and identifying the biomolecules of the analyte-biomolecule complexes by correlating the location of the analyte-biomolecule complexes with particular bead types, based on the unique chemical or physical characteristics of the beads.