► Fabrication and characterization of a polarization-selective Raman biosensor. ► Surface Plasmon Resonances in nanoantenna structures enhance the Raman signal. ► Optical transmittance and SERS signal confirm the polarization-dependent response. We report on the fabrication and spectroscopic characterization of a polarization-selective Raman sensor composed of an ordered array of planar nanoantennas. The device shows two distinct plasmon resonances associated with the main axes of the elongated nanostructures and is able to significantly enhance the Raman signal when the excitation wavelength matches one of these resonances.