DNA i-Motifs Reversibly Disperse and Modulate the Photophysical Properties of an Aggregated Zinc Phthalocyanine Photosensitizer, Triggered by pH and Temperature.
- 1School of Chemistry, University College Dublin, Dublin 4D04 V1W8, Ireland.
- 2Department of Pure and Applied Chemistry, University of Strathclyde, GlasgowG1 1XL, U.K.
Abstract
Cytosine-rich DNA i-motifs (iM) efficiently and reversibly disperse aggregated cationic zinc phthalocyanine (Pc) photosensitizer 1 into a monomeric DNA-bound form with turned-on near-infrared emission and singlet oxygen (1O2) photosensitization. Aggregate disruption and binding occur exclusively with folded iMs, enabling pH- and temperature-controlled switching of Pc photophysics. Circular dichroism (CD) titrations and thermal denaturation studies with biologically relevant iMs, including those formed from the human telomere and cMYC oncogene promoter sequences, reveal sequence-dependent dispersion efficiency. Several folded iMs rival G-quadruplex DNA in disrupting Pc aggregates, while unfolded iMs and duplex DNA are ineffective. Spectroscopic and thermal analyses indicate that binding is favored by structural flexibility and partially folded states. Importantly, iM-mediated dispersion switches on reversible 1O2 photosensitization under acidic conditions. These findings identify DNA iMs as potent and previously unrecognized regulators of Pc photosensitizer aggregation, providing a potential DNA-gated responsive strategy for modulating their photodynamic versus photothermal activity.
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BibTeX
@article{windle2026imotifs,
title = {{DNA i-Motifs Reversibly Disperse and Modulate the Photophysical Properties of an Aggregated Zinc Phthalocyanine Photosensitizer, Triggered by pH and Temperature.}},
author = {Eleanor R Windle and Nadia Elghobashi-Meinhardt and Robert M Edkins and Susan J Quinn},
journal = {The journal of physical chemistry letters},
year = {2026},
month = sep,
doi = {10.1021/acs.jpclett.6c01427},
url = {https://europepmc.org/article/MED/42915489},
note = {CC BY},
}
RIS
TY - JOUR
TI - DNA i-Motifs Reversibly Disperse and Modulate the Photophysical Properties of an Aggregated Zinc Phthalocyanine Photosensitizer, Triggered by pH and Temperature.
AU - Eleanor R Windle
AU - Nadia Elghobashi-Meinhardt
AU - Robert M Edkins
AU - Susan J Quinn
PY - 2026
DA - 2026/09/01
JO - The journal of physical chemistry letters
DO - 10.1021/acs.jpclett.6c01427
UR - https://europepmc.org/article/MED/42915489
AB - Cytosine-rich DNA i-motifs (iM) efficiently and reversibly disperse aggregated cationic zinc phthalocyanine (Pc) photosensitizer 1 into a monomeric DNA-bound form with turned-on near-infrared emission and singlet oxygen (1O2) photosensitization. Aggregate disruption and binding occur exclusively with folded iMs, enabling pH- and temperature-controlled switching of Pc photophysics. Circular dichroism (CD) titrations and thermal denaturation studies with biologically relevant iMs, including those formed from the human telomere and cMYC oncogene promoter sequences, reveal sequence-dependent dispersion efficiency. Several folded iMs rival G-quadruplex DNA in disrupting Pc aggregates, while unfolded iMs and duplex DNA are ineffective. Spectroscopic and thermal analyses indicate that binding is favored by structural flexibility and partially folded states. Importantly, iM-mediated dispersion switches on reversible 1O2 photosensitization under acidic conditions. These findings identify DNA iMs as potent and previously unrecognized regulators of Pc photosensitizer aggregation, providing a potential DNA-gated responsive strategy for modulating their photodynamic versus photothermal activity.
SN - 1948-7185
ER -