Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Biomanufacturing of CdS quantum dots

24.06.2015

A bacterial method for the low-cost, environmentally-friendly synthesis of aqueous soluble quantum dot nanocrystals

A team of Lehigh University engineers have demonstrated a bacterial method for the low-cost, environmentally friendly synthesis of aqueous soluble quantum dot (QD) nanocrystals at room temperature.


Using an engineered strain of Stenotrophomonas maltophilia to control particle size, Lehigh researchers biosynthesized quantum dots using bacteria and cadmium sulfide to provide a route to low-cost, scalable and green synthesis of CdS nanocrystals with extrinsic crystallite size control in the quantum confinement range. The result is CdS semiconductor nanocrystals with associated size-dependent band gap and photoluminescent properties.

Credit: Linda Nye for Lehigh University

Principal researchers Steven McIntosh, Bryan Berger and Christopher Kiely, along with a team of chemical engineering, bioengineering, and material science students present this novel approach for the reproducible biosynthesis of extracellular, water-soluble QDs in the July 1 issue of the journal Green Chemistry. This is the first example of engineers harnessing nature's unique ability to achieve cost effective and scalable manufacturing of QDs using a bacterial process.

Using an engineered strain of Stenotrophomonas maltophilia to control particle size, the team biosynthesized QDs using bacteria and cadmium sulfide to provide a route to low-cost, scalable and green synthesis of CdS nanocrystals with extrinsic crystallite size control in the quantum confinement range.

The solution yields extracellular, water-soluble quantum dots from low-cost precursors at ambient temperatures and pressure. The result is CdS semiconductor nanocrystals with associated size-dependent band gap and photoluminescent properties.

This biosynthetic approach provides a viable pathway to realize the promise of green biomanufacturing of these materials. The Lehigh team presented this process recently to a national showcase of investors and industrial partners at the TechConnect 2015 World Innovation Conference and National Innovation Showcase in Washington, D.C. June 14-17.

"Biosynthetic QDs will enable the development of an environmentally-friendly, bio-inspired process unlike current approaches that rely on high temperatures, pressures, toxic solvents and expensive precursors," Berger says. "We have developed a unique, 'green' approach that substantially reduces both cost and environmental impact."

Quantum dots, which have use in diverse applications such as medical imaging, lighting, display technologies, solar cells, photocatalysts, renewable energy and optoelectronics, are typically expensive and complicated to manufacture. In particular, current chemical synthesis methods use high temperatures and toxic solvents, which make environmental remediation expensive and challenging.

This newly described process allows for the manufacturing of quantum dots using an environmentally benign process and at a fraction of the cost. Whereas in conventional production techniques QDs currently cost $1,000-$10,000 per gram, the biomanufacturing technique cuts that cost to about $1-$10 per gram. The substantial reduction in cost potentially enables large-scale production of QDs viable for use in commercial applications.

"We estimate yields on the order of grams per liter from batch cultures under optimized conditions, and are able to reproduce a wide size range of CdS QDs," said Steven McIntosh.

The research is funded by the National Science Foundation's Division of Emerging Frontiers in Research and Innovation (EFRI Grant No. 1332349) and builds on the success of the initial funding, supplied by Lehigh's Faculty Innovation Grant (FIG) and Collaborative Research Opportunity Grant (CORE) programs.

The Lehigh research group is also investigating, through the NSF's EFRI division, the expansion of this work to include a wide range of other functional materials. Functional materials are those with controlled composition, size, and structure to facilitate desired interactions with light, electrical or magnetic fields, or chemical environment to provide unique functionality in a wide range of applications from energy to medicine.

McIntosh said, "While biosynthesis of structural materials is relatively well established, harnessing nature to create functional inorganic materials will provide a pathway to a future environmentally friendly biomanufacturing based economy. We believe that this work is the first step on this path."

###

The research was conducted by principal investigators McIntosh, Berger, and Kiely along with Zhou Yang and Victoria F. Bernard of the Department of Chemical and Biomolecular Engineering; as well as Li Lu and Qian He of the Department of Materials Science and Engineering, all from Lehigh.

Full article in Green Chemistry: http://pubs.rsc.org/en/Content/ArticleLanding/2015/GC/C5GC00194C?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29&utm_content=Google+Feedfetcher#!divAbstract

Jordan Reese | EurekAlert!

More articles from Materials Sciences:

nachricht Machine-learning predicted a superhard and high-energy-density tungsten nitride
18.07.2018 | Science China Press

nachricht In borophene, boundaries are no barrier
17.07.2018 | Rice University

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Machine-learning predicted a superhard and high-energy-density tungsten nitride

18.07.2018 | Materials Sciences

NYSCF researchers develop novel bioengineering technique for personalized bone grafts

18.07.2018 | Life Sciences

Why might reading make myopic?

18.07.2018 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>