1 research outputs found
Light-Induced Fluorescence Modulation of Quantum Dot-Crystal Violet Conjugates: Stochastic Off–On–Off Cycles for Multicolor Patterning and Super-Resolution
Photoswitching
or modulation of quantum dots (QDs) can be promising
for many fields that include display, memory, and super-resolution
imaging. However, such modulations have mostly relied on photomodulations
of conjugated molecules in QD vicinity, which typically require high
power of high energy photons at UV. We report a visible light-induced
facile modulation route for QD-dye conjugates. QD crystal violets
conjugates (QD-CVs) were prepared and the crystal violet (CV) molecules
on QD quenched the fluorescence efficiently. The fluorescence of QD-CVs
showed a single cycle of emission burst as they go through three stages
of (i) initially quenched “off” to (ii) photoactivated
“on” as the result of chemical change of CVs induced
by photoelectrons from QD and (iii) back to photodarkened “off”
by radical-associated reactions. Multicolor on-demand photopatterning
was demonstrated using QD-CV solid films. QD-CVs were introduced into
cells, and excitation with visible light yielded photomodulation from
“off” to “on” and “off”
by nearly ten fold. Individual photoluminescence dynamics of QD-CVs
was investigated using fluorescence correlation spectroscopy and single
QD emission analysis, which revealed temporally stochastic photoactivations
and photodarkenings. Exploiting the stochastic fluorescence burst
of QD-CVs, simultaneous multicolor super-resolution localizations
were demonstrated