USE OF EXTREMOPHILIC BACTERIA FOR THE NEW GENERATION OF QUANTUM DOTS: BIOSYNTHESIS OF PHOTOSTABLE QUANTUM DOTS BY UV-RESISTANT ANTARCTIC BACTERIA
Abstract
Quantum Dots (QDs) are fluorescent nanoparticles with excellent optical and optoelectronic properties useful in many industrial applications. Currently, chemically synthesized QDs have enormous applications in defense. However, for many space applications it is necessary to search for QDs with a long lifetime after exposure to high-energy radiation. In recent years, microbial bionanotechnology has developed the synthesis of nanomaterials using microorganisms as a low-cost and environmentally friendly process. In this context, a new generation of QDs biosynthesized by extremophilic microorganisms has emerged, generating QDs with unique properties. Our group has reported the use of acidophilic (Acidithiobacillus thiooxidans) and halophilic (Hallobacillus sp.) extremophile bacteria for the biosynthesis of CdS QDs with higher stability at acidic pH and high salinity, respectively, compared to QDs biosynthesized by mesophilic organisms (Escherichia coli) or using chemical methods (Ulloa et al 2016; Bruna et al 2019). QDs biosynthesized by these bacteria present an organic capping mainly composed of proteins, biomolecules that would be responsible for their unique properties. In this sense, preliminary results of our group determined that 3 UV-resistant extremophilic bacteria isolated from Union Glacier in Antarctica biosynthesize QDs with high photostability, particularly when exposed to high-energy radiation (Instituto Antarctica de Chile, INACH Grant RT-19_11). 16s rRNA gene analysis determined that the three isolates correspond to Arthrobacter. These Antarctic isolates synthesize QDs with increased photostability after exposure to UV radiation (300 or 360 nm) when compared to QDs biosynthesized by Escherichia coli or produced by chemical methods. Based on this, the isolation of UV-resistant extremophilic bacteria from Antarctica, particularly from hyper-extreme environments with high exposition to UV radiation (24 h sunlight exposure to high levels of UV radiation during the summer), such as the Union Glacier in the Ellsworth mountains, represents an unvaluable opportunity to discover extremophile bacteria capable to biosynthesize photostable QDs. In addition, the structural, physical, and chemical characterization of photostable QDs, but particularly the study of the proteins bound to the nanocrystal, will allow us to explain the high photostability of these biological QDs. This knowledge will be used for the development of new methods to produce QDs with long life-time exposure to high-energy radiation for space applications.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 20, 2023
- Source ID
- FA95502210509
Entities
People
- Jose Perez Donoso
Organizations
- Air Force Office of Scientific Research
- Andrés Bello University
- United States Air Force