Triplet-triplet annihilation upconversion for calcium sensing

ChemRxiv

Abstract

Triplet-triplet annihilation upconversion is a bimolecular process converting low-energy light into high-energy one. All available calcium probes, despite their qualities, are downconverting, which leads to the autofluorescence caused by background emission of the intra- and intercellular molecules. Here we report a calcium-sensing system working via upconverted emission. The probe itself was obtained by covalent conjugation of a perylene blue emitter with a calcium-chelating moiety; it was sensitized by a red-light absorbing palladium porphyrin. Sensing was selective towards Ca2+ and occurred in the micromolar domain in aqueous solutions and methanol. The upconverted luminescence only appeared in the presence of calcium ions, with a quantum yield of up to 0.0018.

Authors 5

1. Valeriia D. Andreeva Aachen

   Leiden University

   Affiliation as printed

   Leiden University

2. Tingxiang Yang

   Leibniz Institute of Photonic Technology

   Affiliation as printed

   Leibniz Institute of Photonic Technology

3. Irene Regeni Aachen

   Leiden University

   Affiliation as printed

   Leiden University

4. Benjamin Dietzek‐Ivanšić

   Leibniz Institute of Photonic Technology · Friedrich Schiller University Jena

   Affiliation as printed

   Friedrich Schiller University Jena

   Leibniz Institute of Photonic Technology

5. Sylvestre A. Bonnet Aachen

   Leiden University

   Affiliation as printed

   Leiden University