Molecular vibration assisted triplet-triplet annihilation nir-upconversion luminescence of fluorescein

• Type: Article in International Scientific Journal
• Date: 2019

Authors

Kumar, A (Author) Other; da Silva, LP (Author) FCUP; Joaquim C G E Esteves da Silva (Author) FCUP; Kumar, K (Author) Other

Journal

Title: Optical Materials

Vol. 96

ISSN: 0925-3467

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 2 Citations

Scopus - 2 Citations

Other information

Authenticus ID: P-00Q-Y5S

DOI: 10.1016/j.optmat.2019.109286

Abstract (EN): Here we report the near-infrared-upconversion (NIR-UC) luminescence of the organic dye fluorescein, without the need of metal-based NIR-UC materials or the use of high-energy and high-cost two-photon absorption excitation (TPA) systems. Fluorescein upconverts NIR light (lambda = 920 nm) to visible light (lambda = 545 nm) in aqueous solutions, with a pH-dependent light-intensity, by using a low-energy and low-cost nanosecond pulsed laser. The NIR-UC of fluorescein is explained with a triplet-triplet annihilation (TTA) mechanism, assisted by molecular vibrations. This work opens the door for deep-penetration bioimaging and photodynamic therapy, as well for NIR-excited TTA, photocatalysis and photovoltaics, by using solely high quantum yield organic molecules.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 5