We investigate the transport properties of azobenzene, a photosensitive molecule which could provide a light-driven switch. The I-V characteristics are studied in the linear response regime using firstprinciple methods and Green function techniques. Focus is made on the effect of contacts such as gold leads or carbon nanotubes. The trans configuration of this molecule proves to be a better conducting element than its metastable cis configuration. Remarkable is that zigzag carbon nanotubes have a strong effect of enhancement in the current features up to four orders of magnitude.