Colloidal Quantum Dots as Saturable Fluorophores
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- 作者：Osip Schwartz ; Ron Tenne ; Jonathan M. Levitt ; Zvicka Deutsch ; Stella Itzhakov ; Dan Oron
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：October 23, 2012
- 年：2012
- 卷：6
- 期：10
- 页码：8778-8782
- 全文大小：1648K
- 年卷期：v.6,no.10(October 23, 2012)
- ISSN：1936-086X
文摘
Although colloidal quantum dots (QDs) exhibit excellent photostability under mild excitation, intense illumination makes their emission increasingly intermittent, eventually leading to photobleaching. We study fluorescence of two commonly used types of QDs under pulsed excitation with varying power and repetition rate. The photostability of QDs is found to improve dramatically at low repetition rates, allowing for prolonged optical saturation of QDs without apparent photodamage. This observation suggests that QD blinking is facilitated by absorption of light in a transient state with a microsecond decay time. Enhanced photostability of generic quantum dots under intense illumination opens up new prospects for fluorescence microscopy and spectroscopy.