New biological method for producing semiconductor quantum dots using de novo proteins

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New biological method for producing semiconductor quantum dots using de novo proteins

Princeton Docket # 22-3839

Quantum dots are an emerging technology with applications in electronics, quantum computing, and biology research. Several methods exist for manufacturing quantum dots, varying in efficacy and end product. Most manufacturing processes are contaminating processes that often utilize heavy metals. For bio-compatible quantum dots, traditional synthesis methods can’t be used as they rely on toxic precursors that are difficult or impossible to remove.


Researchers at Princeton University’s Department of Chemistry have developed a new method for producing metal chalcogenide semiconductor quantum dots using synthetic de novo proteins. These engineered proteins avoid many of the drawbacks associated with natural proteins such as instability, resistance to modification, and difficulty of preparation and isolation. The reaction relies on a common cofactor, and catalyzes the reactions with HS as a byproduct. HS can be separated for other commercial uses. The proteins can be easily tuned and modified to improve their performance.


The quantum dots have optical properties consistent with other methods for producing quantum dots. The material properties and physical sizes of these quantum dots corroborate the formation of nanocrystals in solutions. This is the first demonstration that de novo proteins can be used to catalyze the synthesis of semiconductor quantum dots.


  • Production of quantum dots
  • Productions of HS, a useful byproduct
  • Remediation of metal-bearing waste stream
  • Other biomineralization applications


  • Proteins are easily prepared
  • Operates under ambient conditions
  • Relatively non-toxic
  • Better size control

Stage of development


The quantum dots were examined using absorbance and fluorescence spectroscopy and further characterized using high-angle annular dark-field scanning transmission electron microscopy.




Michael Hecht, Ph.D. is a Professor of Chemistry at Princeton University. He completed his Ph.D. in Prof. Robert Sauer's lab in the Biology Department at MIT, where he did research on protein stability and protein/DNA interactions. He then did post-doctoral research on protein design in the labs of Profs. David and Jane Richardson in the Biochemistry Department at Duke University Medical School. At Princeton, Hecht has served as the Director of Undergraduate Studies and Associate Chair of the Chemistry Department. In addition to his work in the Chemistry Department, Hecht served two terms as the Head of Forbes College, one of the 6 undergraduate Colleges at Princeton. Research in the Hecht group focuses on Synthetic Biology, Origin of Life, and Protein Design.

Sarangan Chari, Ph.D.  is a graduate alumnus of the Princeton Chemistry Department having done his doctoral work on carboranes under the guidance of Prof. Maitland Jones, Jr. After many forays in industrial and academic labs, he wound up as an investment banker. Having seen the error of his ways, he is back in science trying his hand at Synthetic Biology. His current project involves deciphering the mechanism of auxotroph rescue by synthetic proteins.

Leah Spangler, Ph.D. will be an Assistant Professor of Chemical and Life Science Engineering at Virginia Commonwealth University as of August 2022. She obtained her Ph.D. in Chemical Engineering from Lehigh University where she studied the single enzyme biomineralization of semiconductor nanocrystals for biomedical and energy applications. Leah continued her research career as a Postdoctoral Research Associate in Prof. Gregory Scholes’ lab in the Department of Chemistry at Princeton University. Leah’s current research interests include the engineering of de novo proteins with enzymatic activity for application in scalable biomaterial synthesis, and using time resolved spectroscopy to elucidate the photophysical mechanisms of newly discovered light absorbance in supramolecular protein systems.


Intellectual Property & Development status

Patent protection is pending.

Princeton is currently seeking commercial partners for the further development and commercialization of this opportunity.


Cortney Cavanaugh
Princeton University Office of Technology Licensing • (609) 258-7256•

Patent Information:
For Information, Contact:
Cortney Cavanaugh
New Ventures and licensing associate
Princeton University
Michael Hecht
Sarangan Chari
Leah Spangler