The photosystem reaction center I is covalently bound to carbon nanotubes using carbodiimide chemistry. The hybrid systems are characterized by atomic force microscopy, and UV-VIS spectroscopy, indicating a high degree of conjugation between the photosystem reaction center and the carbon nanotubes. Three different architectures for optoelectronic circuits are presented, which have the potential to serve as basis for molecular optoelectronic devices.