A Single Molecule Investigation of the Photostability of Quantum Dots

Eva Arnspang Christensen, Pasad Kulatunga, B. Christoffer Lagerholm

Research output: Contribution to journalJournal articleResearchpeer-review


Quantum dots (QDs) are very attractive probes for multi-color fluorescence applications. We report here however that single QDs that are subject to continuous blue excitation from a 100W mercury arc lamp will undergo a continuous blue-switching of the emission wavelength eventually reaching a permanent dark, photobleached state. We further show that β-mercaptoethanol has a dual stabilizing effect on the fluorescence emission of QDs: 1) by increasing the frequency of time that a QD is in its fluorescent state, and 2) by decreasing the photobleaching rate. The observed QD color spectral switching is especially detrimental for multi-color single molecule applications, as we regularly observe spectral blue-shifts of 50 nm, or more even after only ten seconds of illumination.
Original languageEnglish
Issue number8
Pages (from-to)e44355
Publication statusPublished - 2012


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