Quantum dots are a special kind of nanoparticle as they can be engineered to have specific properties, such as what frequencies of light they interact with. For that reason researchers are looking to them for sensors and light emitters, but they are easily influenced by other particles, which complicates any work with them. Now researchers at the National Institute of Standards and Technology have done the time consuming work to understand these influences.
These influences are not limited to the nanoscale as it is the same physics that explains why moving one's hand near an antenna can affect its reception. With quantum dots though the effect is to change the intensity of light emitted and change how lone the dot glows. To study it the researchers made up batches of DNA origami that uses DNA to hold the quantum dots to gold nanoparticles in a rectangle, but the distance between the particles and the size of the gold nanoparticles varied. The researchers illuminated and tracked the rectangles with a laser, to learn how the variations and interactions with other particles in the solution affected the glow of the quantum dots.
It was time consuming, but in the end the researchers had the data they need to design quantum dots with specific lifetimes, an important ability for future technologies based on quantum dots. Also the tracking system used to follow the quantum dots may lead to better measurement techniques.