Quantum dots (QDs) of non-blinking optical properties are of great use in real time imaging of biomolecular processes; they also provide much-improved nanomaterials to design and construct photonic devices for applications ranging from energy to biophotonics. The two grand challenges in the field of quantum dots are (1) to achieve robust non-blinking QDs and (2) to assemble different QDs of unique optical properties into hierarchically organized nanoarchitectures, challenges that are difficult to meet using a top-down lithographic approach.
Researchers at the Biodesign Institute of Arizona State University have developed the use of self-assembling DNA nanostructures to provide unprecedented control of spatial arrangement of QDs in 2- and 3-dimensions. The hierarchy of QDs that can be synthesized by this “green” phosphine-free colloidal method includes alloyed QDs, thick shell QDs, and multi-shell QDs in ZnCdSSe and other formulations. Additional nanostructures that have been produced by these methods include nanowires, quantum rods, and quantum sheets and ribbons, in ZnS, ZnS:Mn, and other formulations.
The complexity thus achieved at the molecular level mimics what exists in nature and far exceeds the current capabilities using top-down lithographic approach. This opens up the possibility of incorporating a remarkable degree of optical and electronic complexity into an optical element system that could be entirely self-assembled.
- Biological imaging, including real-time imaging of biomolecular processes
- Photonic devices for applications such as
- Photonic displays
Benefits and Advantages
- "Green" synthesis technology
- Band edge emissions that are tunable across the entire visible spectrum
- Band gap can be hybrid engineered by tuning both the composition and size of the nanoparticle
- A series of QDs can be constructed having uniform size with a range of PL emissions
- Can be constructed in several different shapes, sizes and proportions