Abstract: The present invention relates to nanoscale polymer dots (Pdots) that include strongly light absorbing semiconducting polymer nanoparticles doped with near-IR emitting dyes. The polymer functions as an antenna and transfers the excitation energy to the doped near-IR emitting dye molecules, which function as the emitting entity. The resulting Pdots feature very bright near-IR emission with emission wavelength tunability, high water solubility, and stability in biological solutions.