Photostability of Semiconductor Quantum Dots in Response to UV Exposure.

The interest in quantum dots (QDs) and their popularity in life science applications stems from their high photostability and unique optical properties such as superior light absorption. Photostability of semiconductor QDs is reportedly higher than that of organic dyes, but QDs may also be affected by light exposure. The outcome of such exposure may depend on many experimental factors, can lead to either an increase or decrease in the photoluminescent efficiency of QDs and is difficult to predict. QDs may therefore require experimental testing for their photostability especially prior to quantitative applications. A simple QD testing procedure described here showed a substantial degree of photobleaching when exposed to UV; nevertheless, the rate of change was noticeably lower than that measured for traditional organic dyes, as expected. The procedure reported is also applicable to traditional organic dyes and allows for quantitative comparisons to be conducted.