The delocalized pi-electronic system of carbon nanotubes allows them to link non-covalently to a large variety of organic molecules. In contrast to covalent functionalization, this mild interaction preserves most of the intrinsic nanotubes properties (photoluminescence, mobility...) but still leads to a strong enough coupling so to give stable supramolecular assemblies and to induce new and efficient functionalities [1]. We focus on nanotubes / chromophores compounds where the latter acts as a nano optical antenna that absorbs light and then transfer almost 100% of the energy to the nanotube [2, 3, 4, 5]. Compounds made of different chromophores such as metal- or free base porphyrins, porphyrin polymers, and cyanines were synthesized by means of the micelle swelling method [1, 7, 8]. Energy transfer was analysed both on ensembles [5, 6] and at the single compound level [9]. We will first discuss the energy transfer mechanisms in these kinds of supramolecular assemblies [5-9]. In a second part, we will show that the new functionalities created by the molecules allow to gain new insight into the intrinsic electronic properties of nanotubes [10] . References [1] C. Roquelet, et al, ChemPhysChem, 11 (2010), 1667 [2] G. Magadur et al. ChemPhysChem, 9 (2008),pp 1250 [3] J. P. Casey et al, Journal of Materials Chemistry, 18, 1510 (2008) [4] S. D. Stranks et al, ACS Nano, 5, (2011), 2307 [5] C. Roquelet, et al, Appl. Phys. Lett. 97 (2010), 141918 [6] F. Ernst et al, Advanced functional materials, 22 (2012), 3921. [6] D. Garrot et al, J. Phys. Chem C 115, (2011) 23283 [7] C. Roquelet, et al ChemPhys in press (http://dx.doi.org/10.1016/j.chemphys.2012.09.004) [8] G. Clavé, et al submitted [9] C. Roquelet et al, ACS Nano 6, (2012), 8796. [10] C. Roquelet et al, in preparation