Title Bidirectional photoswitching of a tailored azobenzene with red and far-red light involving triplet sensitization in an aqueous system
Authors Miroshnichenko, Mila ; Hölzel, Helen ; Orentas, Edvinas ; Kazlauskas, Karolis ; Ferreira, Pedro ; Dumoulin, Fabienne ; Alcaide, Carles ; Solà, Miquel ; Bresolí-Obach, Roger ; Nonell, Santi ; Bharmoria, Pankaj ; Moth-Poulsen, Kasper
DOI 10.1002/advs.75155
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Is Part of Advanced science.. Weinheim : Wiley-VCH GmbH. 2026, vol. 13, iss. 36, art. no. e75155, p. [1-17].. eISSN 2198-3844
Keywords [eng] azobenzene ; photoswitching ; singlet-oxygen ; spectral shift ; triplet-sensitization
Abstract [eng] Shifting action spectrum of azobenzene-based photopharmaceuticals toward bio-optical window is highly desired, since red/far-red light offers improved tissue penetration and reduced cellular toxicity. While unidirectional photoswitching (trans-to-cis and cis-to-trans) of azobenzenes (AZO) with red/far-red light is known in separate systems, achieving bidirectional photoswitching in a single system faces issues of spectral overlaps. Here, bidirectional photoswitching of a tailored azobenzene is achieved in a single bio-relevant solution with red and far-red light excitation. A new azobenzene molecule (AZO-N) bearing four ortho-methoxy, and one para-N donor lipophile is synthesized. The AZO-N exhibits separate n-π* absorption bands and triplet energies for trans and cis isomers. As a result, trans-to-cis photoswitching is observed upon 625 nm excitation at the tail of the red-shifted n-π*absorption band via direct absorption, whereas cis-to-trans photoswitching is enabled upon 730 nm excitation through triplet sensitization. Further, triplet sensitization of AZO-based molecules could lead to singlet oxygen generation—experiments in the presence of serum albumin and glutathione (biological oxidative stress addressors), suggest no effect of singlet oxygen on the triplet-sensitization of cis-AZO-N, and non-significant change in the fingerprint all-α secondary structure of serum albumin. This advance presents modular design principles to develop practically functional azo-based photopharmaceuticals.
Published Weinheim : Wiley-VCH GmbH
Type Journal article
Language English
Publication date 2026
CC license CC license description