We demonstrate spectra of slabs of plasmonic 1D nanostructures and show their ability to detect a specific binding of low-density lipoproteins. Optical spectra of the slabs exhibiting a spectrally sharp resonant peak have been analyzed numerically to demonstrate responses of biosensors under study. We show that the sensitivity to biomolecular binding can be considerably increased by utilizing magnetooptical materials as constituent element of plasmonic 1D nanostructures.