New sensing films have been developed for the detection of molecular oxygen. These films are based on luminescent Ir(III) dyes incorporated either into polystyrene (with and without plasticizer) or metal oxide, nanostructured material. The preparation and characterization of each film have been investigated in detail. Due to their high sensitivity for low oxygen concentration, the parameters p(O2)(S = 1/2) and Delta I-1% have been also evaluated in order to establish the most sensitive membrane for controlling concentrations between 0 and 10% and low oxygen concentrations (lower than 1%), respectively. The results show that the use of nanostructured material increased the sensitivity of the film; the most sensitive membrane for controlling 02 between 0 and 10% is based on N1001 immobilized in AP200/19 (k(SV) = 2848 +/- 101 bar(-1) and p(O2)(S = 1/2) = 0.0006), and the complex N969 incorporated into AP200/19 seems to be the most suitable for applications in oxygen trace sensing (Delta I-1% = 93.13 +/- 0.13%). (C) 2010 Elsevier B.V. All rights reserved.