Hydrothermal synthesis of chiral carbon dots
Abstract
Nanocolloids that are cumulatively referred to as nanocarbons, attracted significant attention during the last decade because of facile synthesis methods, water solubility, tunable photoluminescence, easy surface modification, and high biocompatibility. Among the latest development in this reserach area are chiral nanocarbons exemplified by chiral carbon dots (CDots). They are expected to have applications in sensing, catalysis, imaging, and nanomedicine. However, the current methods of CDots synthesis show often contradictory chemical/optical properties and structural information that required a systematic study with careful structural evaluation. Here, we investigate and optimize chiroptical activity and photoluminescence of L‐ and D‐CDots obtained by hydrothermal carbonization of L‐ and D‐cysteine, respectively. Nuclear magnetic resonance spectroscopy demonstrates that they are formed via gradual dehydrogenation and condensation reactions of the starting amino acid leading to particles with a wide spectrum of functional groups including aromatic cycles. We found that the chiroptical activity of CDots has an inverse correlation with the synthesis duration and temperature, whereas the photoluminescence intensity has a direct one, which is associated with degree of carbonization. Also, our studies show that the hydrothermal synthesis of cysteine in the presence of boric acid leads to the formation of CDots rather than boron nitride nanoparticles as was previously proposed in several reports. These results can be used to design chiral carbon‐based nanoparticles with optimal chemical, chiroptical, and photoluminescent properties.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Oct 27, 2022
- Source ID
- 10.1002/chir.23509
Entities
People
- Anastasia K Visheratina
- Ashleigh K. Wilson
- Leila Hesami
- M. A. Noginov
- Natalia Noginova
- Nicholas A. Kotov
- Nicole Baalbaki
Organizations
- Air Force Office of Scientific Research
- Michigan State University College of Engineering
- National Nuclear Security Administration
- National Science Foundation
- Norfolk State University
- Sandia National Laboratories
- United States Department of Defense
- University of Michigan