The effect of linker length on biol. recognition at the air-water interface using energy transfer between a fluorescent conjugated polymer and dye-labeled protein. A longer linker provided greater binding of the protein as evidence by the dramatically increased energy transfer. This may be due to an increased hydrophilicity of the side chain, which allowed the biotin to better access the streptavidin located in the aq. subphase. Subtle changes in the polymer structure can thus have important consequences for analyte recognition. [on SciFinder(R)]