Abstrakti
Cyanine dyes, as used in super-resolution fluorescence microscopy, undergo light-induced “blinking”, enabling localization of fluorophores with spatial resolution beyond the optical diffraction limit. Despite a plethora of studies, the molecular origins of this blinking are not well understood. Here, we examine the photophysical properties of a bio-conjugate cyanine dye (AF-647), used extensively in dSTORM imaging. In the absence of a potent sacrificial reductant, light-induced electron transfer and intermediates formed via the metastable, triplet excited state are considered unlikely to play a significant role in the blinking events. Instead, it is found that, under conditions appropriate to dSTORM microscopy, AF-647 undergoes reversible photo-induced isomerization to at least two long-lived dark species. These photo-isomers are characterized spectroscopically and their interconversion probed by computational means. The first-formed isomer is light sensitive and transforms to a longer-lived species in modest yield that could be involved in dSTORM related blinking. Permanent photobleaching of AF-647 occurs with very low quantum yield and is partially suppressed by the anaerobic redox buffer.
Alkuperäiskieli | Englanti |
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Sivut | 14983-14998 |
Julkaisu | Chemistry - A European Journal |
DOI - pysyväislinkit | |
Tila | Julkaistu - 13 syysk. 2019 |
Julkaistu ulkoisesti | Kyllä |
OKM-julkaisutyyppi | A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä |