Yanmei He
Postdoctoral fellow
Sensing Mechanism and Excited-State Dynamics of a Widely Used Intracellular Fluorescent pH Probe : pHrodo
Author
Summary, in English
The pHrodo with an “off–on” response to the changes of pH has been
widely used as a fluorescent pH probe for bioimaging. The fluorescence
off–on mechanism is fundamentally important for its application and
further development. Herein, the sensing mechanism, especially the
relevant excited-state dynamics, of pHrodo is investigated by
steady-state and time-resolved spectroscopy as well as quantum chemical
calculations, showing that pHrodo is best understood using the
bichromophore model. Its first excited state (S1) is a charge transfer state between two chromophores. From S1, pHrodo relaxes to its ground state (S0) via an ultrafast nonradiative process (∼0.5 ps), which causes its fluorescence to be “off”. After protonation, S1
becomes a localized excited state, which accounts for the fluorescence
being turned “on”. Our work provides photophysical insight into the
sensing mechanism of pHrodo and indicates the bichromophore model might
be relevant to a wide range of fluorescent probes.
widely used as a fluorescent pH probe for bioimaging. The fluorescence
off–on mechanism is fundamentally important for its application and
further development. Herein, the sensing mechanism, especially the
relevant excited-state dynamics, of pHrodo is investigated by
steady-state and time-resolved spectroscopy as well as quantum chemical
calculations, showing that pHrodo is best understood using the
bichromophore model. Its first excited state (S1) is a charge transfer state between two chromophores. From S1, pHrodo relaxes to its ground state (S0) via an ultrafast nonradiative process (∼0.5 ps), which causes its fluorescence to be “off”. After protonation, S1
becomes a localized excited state, which accounts for the fluorescence
being turned “on”. Our work provides photophysical insight into the
sensing mechanism of pHrodo and indicates the bichromophore model might
be relevant to a wide range of fluorescent probes.
Department/s
- Chemical Physics
- NanoLund: Centre for Nanoscience
Publishing year
2023-11-23
Language
English
Pages
10482-10488
Publication/Series
The Journal of Physical Chemistry Letters
Volume
14
Issue
46
Document type
Journal article
Publisher
The American Chemical Society (ACS)
Topic
- Physical Chemistry (including Surface- and Colloid Chemistry)
Status
Published
ISBN/ISSN/Other
- ISSN: 1948-7185