Tuned red NIR phosphorescence of polyurethane hybrid composites embedding metallic nanoclusters for oxygen sensing

Polyurethane nanocomposites with high content of red NIR luminescent transition metal clusters are presented. The gas permeability of the hybrid material is controlled by adjusting the hard/soft segment ratio of the organic matrix structure leading to a drastic and reversible enhancement of cluster luminescence depending on the molecular oxygen concentration in its surrounding atmosphere.