DNA-Templated Silver Nanoclusters: A Fluorescent Dye with Novel Applications to Luminescent Solar Concentrators
Open Access
- Author:
- Stanko, Danielle Renee
- Area of Honors:
- Physics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Bruce Paul Wittmershaus, Thesis Supervisor
Prof. Richard Wallace Robinett, Thesis Honors Advisor - Keywords:
- luminescent solar concentrator
solar energy
silver nanocluster
fluorescent dye
dye photostability
polyvinyl alcohol - Abstract:
- Silver nanoclusters are groups of 20 or fewer silver atoms with distinct physical properties unlike bulk silver. When prohibited from aggregating, they form a fluorescent material similar to some organic dyes, and vary in color depending on size and other chemical interactions. Silver atoms are attracted to unpaired DNA bases, especially cytosine. In solution, they bond and the DNA isolates nanoclusters of silver, preventing aggregation. This also provides some control of the optical properties of the dye as different DNA sequences yield varying results. Up to this point, the chief application for silver nanoclusters is as a biosensor. Their simple synthesis and compatibility with biological environments make them useful as visual biosensors. However, the experiment described in this thesis explores the properties of DNA-templated silver nanoclusters (AgNCs) with applications to luminescent solar concentrators (LSCs). LSCs concentrate sunlight onto photovoltaic cells using a fluorescent plastic that is cheaper than the photovoltaic cells themselves, decreasing the overall cost of solar energy conversion. Although biological applications only require a few hours of stability, use in a solar concentrator would require AgNCs to remain fluorescent for many years. If achieved, AgNCs could potentially be a novel dye for LSCs. Most AgNC samples kept in water at room temperature only fluoresce for a few days. This study investigates ways to increase nanocluster stability by excluding oxygen, drying the sample on glass as a film, and drying the sample in poly-vinyl alcohol (PVA), along with combinations of these variables. One particular sample has remained fluorescent for 20 months, so although it is not ready to be used in an LSC, the possibility still remains. More precise measurement techniques and exploration of different DNA-template sequences will be needed to validate its application as a fluorescent dye to concentrate solar photons. In future experiments, the goal is to further improve the stability of this material and expand its current applications from biology to solar energy.