@article{10272/28494,
year = {2026},
url = {https://hdl.handle.net/10272/28494},
abstract = {Multiphoton excitation (MPE) processes enable three-dimensionally confined fluorescence with reduced background as well as improved image contrast and signal-to-noise ratio. However, MPE finds major technological limitations derived from the need for high light intensities at long excitation wavelengths. To circumvent these challenges, we herein propose a molecular strategy that reproduces multiphoton-like nonlinear responses using only sequential one-photon excitations (1PE). A dyad (2for1), consisting of the acedan fluorophore covalently connected to a spironaphthopyran photoswitch, shows a quadratic dependence of the emission intensity on the excitation intensity, thus emulating a two-photon absorption behavior. The incorporation of a BODIPY photocage to this construct yields a triad (3for1) that results in an even stronger nonlinear fluorescence response. These findings pave the way for sequential 1PE as a practical approach to capitalize on the benefits of nonlinear fluorescence while avoiding the inherent limitations of simultaneous MPE.},
organization = {The authors are grateful for the financial support from the European Innovation Council and SMEs Executive Agency (EISMEA) for the EIC PATHFINDER project 101098934−4 for 2. J. A. thanks the Swedish Research Council VR (projects 2021-05311 and 2025-05450).},
publisher = {American Chemical Society},
title = {Molecular Engineering for Nonlinear Fluorescence: En Route to Three-Photon Absorption via Sequential One-Photon Excitation},
doi = {10.1021/jacs.6c03621},
author = {Oh, Jinyoung and Benítez Martín, Carlos and Fron, Eduard and Hofkens, Johan and Pischel, Uwe and Grøtli, Morten and Andréasson, Joakim},
}