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Luminescent Sensing of Oxygen Using a Quenchable Probe and Upconverting Nanoparticles


  • D.E.A. thanks the German Research Council (DFG, Bonn) for a stipend as part of the graduate college GRK 640 (Natural and Artificial Photoreceptors). We wish to thank S. M. Borisov (TU Graz) for kindly providing the oxygen probe [Ir(CS)2(acac)].


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Turned off by oxygen: Luminescent upconverting nanoparticles (UCNPs) of the type NaYF4:Yb,Tm are employed in an entirely new type of optical sensor for oxygen (see picture). Upon laser excitation at 980 nm, these UCNPs act as nanolamps, the blue emission of which is used to photoexcite an iridium complex dissolved in ethyl cellulose. Its green emission, in turn, is dynamically and fully reversibly quenched by molecular oxygen.