We used a confocal laser microscope to investigate the one-photon photoluminescence (PL) of gold antennas. The PL spectra can be precisely fitted to a plasmon - enhanced PL model. For increasing the antenna length, the energy peak position decreases continuously until it reaches a value of 1.7 - 1.8 eV. For longer antennas and smaller plasmon energies, we observe an additional, persistent shoulder in the PL spectra, which we explain by a Gaussian - shaped peak at Delta(X) approximate to 1.78 - 1.79 eV. We attribute this behavior to the opening of an additional decay path for electrons at the gold interband transition edge, which we observe only for long antennas. (C) 2016 Optical Society of America