Because quantum dots emit and absorb light so efficiently, the idea of using them as light sources for bioimaging is compelling. But their characteristic and unpredictable blinking is a significant drawback, and according to Anton Malko, assistant professor at the University of Texas at Dallas (UT Dallas), the ability to control this effect is necessary to facilitate their widespread use. Now Malko and colleagues from Los Alamos National Laboratory (Los Alamos, TX) have figured a way to do just that, by increasing the size of the exterior shell of quantum dots from approximately 4 to 15 nm.1
"We observed that the same process that causes the dots to blink didn't have the same effect when we scaled up the size," he said, adding that complete suppression of blinking is possible for large-shell dots. The researchers hope that a better understanding of the forces at work in this phenomenon will allow the production of quantum dots with uninterrupted light output.
1. A.V. Malko et al., Nano Lett., 11, 12, 5213–5218 (2011).