Abstract: Complexes of a biotinylated fluorescent polymer and a biotin binding protein and solid supports coated with the fluorescent polymer complexes are described. The complexes can be used as sensors for detecting biological recognition events (e.g., nucleic acid hybridization reactions or enzymatic induced polypeptide cleavage). Methods of making the complexes and methods of using the complexes for detecting the presence and/or amount of a target analyte in a sample are also described. The target analyte can be an enzyme (e.g., &bgr;-secretase) or a nucleic acid (e.g., a single stranded or double stranded nucleic acid).