In this paper, we focus our attention on the morphological and optical characterisation of self-assembled Zn-porphyrin-based/fullerene systems. Diethynyl-Zn-porphyrin (ZnDEP) and bimetallic sigma-bonded arrays of diethynyl-Zn-porphyrin with Pd(II) and Pt(II) square planar complexes, namely, ZnDEP, Pd-ZnDEP and Pt-ZnDEP, have been synthesised, and these compounds were studied in the self-assembly behaviour with fullerene, giving rise to the molecular composites ZnDEP/C-60, Pd-ZnDEP/C-60 and Pt-ZnDEP/C-60. Thick films of the materials were deposited by slow evaporation on glass substrates, in order to be morphologically characterised by scanning electron microscopy (SEM) technique. The surface analysis showed a peculiar nanometric structure of the composites. The optical (UV-Vis absorption and emission) characterisation of toluene solutions and a preliminary study on the molecular oxygen luminescence quenching of diethynyl-Zn-porphyrin, diethynyl-Zn-porphyrin/fullerene and platinum or palladium-containing homologues have been performed and will be here discussed. A luminescence response towards molecular oxygen was observed in the case of ZnDEP and ZnDEP/C-60 samples with a lowering of the intensity of the emission, suggesting promising applications in optical sensors. (C) 2003 Elsevier B.V. All rights reserved.