Triplet–Triplet Annihilation Upconversion-Based Oxygen Sensors to Overcome the Limitation of Autofluorescence

• Published in: ACS sensors Vol. 8; no. 8; pp. 3043 - 3050
• Main Authors: Mendonsa, Adrian A., Soeldner, Cassandra C., Mudd, Natalie E., Saccomano, Samuel C., Cash, Kevin J.
• Format: Journal Article
• Language: English
• Published: United States American Chemical Society 25-08-2023
• Subjects: Fluorescent Dyes; Oxygen; Saccharomyces cerevisiae; triplet−triplet annihilation; upconversion; autofluorescence; oxygen; nanosensor
• ISSN: 2379-3694; 2379-3694
• DOI: 10.1021/acssensors.3c00548

Autofluorescence is one of the many challenges in bioimaging as it can mask the emission from fluorescent probes or markers, a limitation that can be overcome via upconversion. Herein, we have developed a nanosensor that uses triplet–triplet annihilation upconversion to optically report changes in the dissolved oxygen concentration. Using a sensitizer–annihilator dye pairing of platinum­(II) octaethylporphyrin and 9,10-diphenylanthracene, we monitored the oxygen consumption (as a proxy for metabolic activity) over time in a biological systemSaccharomyces cerevisiae (brewing yeast). The nanosensor demonstrated good reversibility over multiple cycles and showed good signal and colloidal stability when tested over the course of 7 days, and it was sensitive to dissolved oxygen from 0.00 to 3.17 mg/L O2. Additionally, there was no signal overlap between the nanosensor emission and S. cerevisiae autofluorescence, thus underscoring the utility of upconversion as a facile and economical means of overcoming autofluorescence.