In this work we show that, the combination of (i) high mechanical stability (provided by a PS matrix), (ii) high sensitivity and selectivity (provided by a two-dye system of Tris (1,10-phenanthroline)ruthenium(II) chloride hydrate (Ru(phen)3) and 7-Methoxy-4-methylcoumarin) and (iii) high reproducibility in the output signal/response, results in a membrane able for monitoring O2 and temperature in membrane processes at laboratory and industrial scales.