Dataset Information

Disentangling optically activated delayed fluorescence and upconversion fluorescence in DNA stabilized silver nanoclusters.

ABSTRACT: Optically activated delayed fluorescence (OADF) is a powerful tool for generating background-free, anti-Stokes fluorescence microscopy modalities. Recent findings, using DNA-stabilized silver nanoclusters (DNA-AgNCs), indicate that OADF is usually accompanied by a dark state-mediated consecutive photon absorption process leading to upconversion fluorescence (UCF). In this study, we disentangle the OADF and UCF process by means of wavelength-dependent NIR excitation spectroscopy. We demonstrate that, by appropriate choice of secondary NIR excitation wavelength, the dark state population can be preferentially depleted through OADF, minimizing the UCF contribution. These findings show that dark state depletion by OADF might enable background-free STED-like nanoscopy.

SUBMITTER: Krause S

PROVIDER: S-EPMC6540914 | biostudies-literature | 2019 May

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Disentangling optically activated delayed fluorescence and upconversion fluorescence in DNA stabilized silver nanoclusters.

Krause Stefan S Cerretani Cecilia C Vosch Tom T

Chemical science 20190424 20

Optically activated delayed fluorescence (OADF) is a powerful tool for generating background-free, anti-Stokes fluorescence microscopy modalities. Recent findings, using DNA-stabilized silver nanoclusters (DNA-AgNCs), indicate that OADF is usually accompanied by a dark state-mediated consecutive photon absorption process leading to upconversion fluorescence (UCF). In this study, we disentangle the OADF and UCF process by means of wavelength-dependent NIR excitation spectroscopy. We demonstrate t ...[more]

PMID: 31191889

Similar Datasets

Project description:Modulating fluorescent protein emission holds great potential for increasing readout sensitivity for applications in biological imaging and detection. Here, we identify and engineer optically modulated yellow fluorescent proteins (EYFP, originally 10C, but renamed EYFP later, and mVenus) to yield new emitters with distinct modulation profiles and unique, optically gated, delayed fluorescence. The parent YFPs are individually modulatable through secondary illumination, depopulating a long-lived dark state to dynamically increase fluorescence. A single point mutation introduced near the chromophore in each of these YFPs provides access to a second, even longer-lived modulatable dark state, while a different double mutant renders EYFP unmodulatable. The naturally occurring dark state in the parent YFPs yields strong fluorescence modulation upon long-wavelength-induced dark state depopulation, allowing selective detection at the frequency at which the long wavelength secondary laser is intensity modulated. Distinct from photoswitches, however, this near IR secondary coexcitation repumps the emissive S1 level from the long-lived triplet state, resulting in optically activated delayed fluorescence (OADF). This OADF results from secondary laser-induced, reverse intersystem crossing (RISC), producing additional nanosecond-lived, visible fluorescence that is delayed by many microseconds after the primary excitation has turned off. Mutation of the parent chromophore environment opens an additional modulation pathway that avoids the OADF-producing triplet state, resulting in a second, much longer-lived, modulatable dark state. These Optically Modulated and Optically Activated Delayed Fluorescent Proteins (OMFPs and OADFPs) are thus excellent for background- and reference-free, high sensitivity cellular imaging, but time-gated OADF offers a second modality for true background-free detection. Our combined structural and spectroscopic data not only gives additional mechanistic details for designing optically modulated fluorescent proteins but also provides the opportunity to distinguish similarly emitting OMFPs through OADF and through their unique modulation spectra.

Dataset Information

Disentangling optically activated delayed fluorescence and upconversion fluorescence in DNA stabilized silver nanoclusters.

Publications

Disentangling optically activated delayed fluorescence and upconversion fluorescence in DNA stabilized silver nanoclusters.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets