compositions of matter and methods for enhancing bioassay performance are disclosed . more particularly , the composition of matter comprises a molecularly compact polymer - ligand conjugate capable of self - orienting on a surface to improve the orientation of the ligand / receptor binding domains within the bioassay at the nanoscopic level . in a preferred embodiment , the molecularly compact polymer comprises a dendrimer polymer such as a fifth generation polyamidoamine dendrimer having exterior surface hydroxyl and amine functional groups , and the ligand / receptor comprises an antibody or fab .