Simultaneous oxygen and temperature ratiometric optical probes based on an europium(III) complex and anthracene covalently bounded to pdms

Simultaneous probing of oxygen and temperature is widely applied in several areas such as blood analysis, bioreactor fluids, chemical industry, aerodynamic research and in the monitoring of food quality control [1]. The use of luminescent probes have the advantages of contactless measurements and the possibility of large and/or micro scale imaging [2]. In this context, the application of lanthanides complexes or nanoparticles for optical probes it is interesting due to the long emission lifetimes, narrow emission bands and large pseudoStokes shifts [3]. In this work we chemically attached the [Eu(bzac)3(H2O)2] complex (red emitter) and the anthracene group (eant - blue emitter) in a pdms matrix resulting on a self-supportable membrane (structural scheme in Fig. 1-a) with high thermal sensitivity to temperature and oxygen level variation (Fig. 1-b). The ratio between the anthracene (380-565 nm range) and europium(III) (602-640 nm range) emissions was used in the luminescent probing. For the temperature probing, the system shows an operational range of 203-323 K and a maximum relative sensitivity of 2.69 % K-1 at 233 K. The oxygen dependence of the emission was measured at 25, 30, 35 and 40 °C and a temperature correction surface (Fig. 1-b) was developed. The results also indicate the existence of an energy transfer from anthracene to europium(III) in this system even though these species are not bound chemically.