Nanotechnology Now

Our NanoNews Digest Sponsors





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Quick and Safe Quantum Dots

Researchers at Rutgers University have developed a method to generate an entire library of safe quantum dots quickly and efficiently.
Researchers at Rutgers University have developed a method to generate an entire library of safe quantum dots quickly and efficiently.

Abstract:
Tracking and viewing molecular interactions inside a cell with great detail is invaluable for understanding how organisms operate and to the future of medicine. Quantum dots (QDs), semiconductor crystals on the nanoscale with confined electron excitations, have almost all the right properties for this task. They have high absorption constants, are small enough to sneak inside cells, and can be tailored to release at different wavelengths. Additionally, they can carry therapeutic proteins on their coating. However, they are toxic. The current leading QDs are composed of hazardous elements like cadmium, selenium, and tellurium. Recently, advances have made more biocompatible crystals out of safer materials, such as zinc, silver, and indium. Yet, these crystals have long reaction times and are difficult to customize and produce en masse.

Quick and Safe Quantum Dots

Germany | Posted on August 10th, 2012

Researchers at Rutgers University have developed a method to generate an entire library of safe QDs quickly and efficiently. They used the molecular structure ZnS-AgInS2 (ZAIS), a version of the previous non-toxic crystals. They placed a powdery bulk chemical precursor into a vial and blasted it with 20 kHz of ultrasound for five minutes. The sound waves broke up the powder into QDs with a uniform size of about 12nm. The crystals also had a property unique among other types of dots. Instead of size controlling the color of emission, the ratio of elements in the compound did. The more zinc or silver added to the precursor, the more blue-shifted the resulting QDs were. By tuning the stoichiometry, the researchers synthesized QD samples across the entire visible spectrum.

They then tested to see how the dots impacted a biological environment. The ZAIS dots were compared against the standard and toxic cadmium selenide (CdSe) QDs. Both were placed with brain tumor cell, marrow stem cell, and mouse fibroblast samples to see how each fared in their presence. In all trials, the ZAIS QDs had negligible toxic effects, even when in high concentration or oxidized by four hours of UV exposure. In contrast, the CdSe QDs failed the tests miserably, practically killing off half the sample at high concentration. Moreover, the ZAIS dots were extremely stable, lasting for two months in storage without losing any of their photoluminescence.

Lastly, the researchers tested how well these QDs could carry out a multifunctional purpose. They mutated a sample of the tumor neurons to create a fluorescent protein that made them glow green. They then attached the silencing RNA that targets and destroys the protein-creating gene to the QD surface. The researchers watched the dots enter the cells, as they were easy to track due to their glow. After three days, about 80% of the green fluorescence disappeared.

These results open up the possibility of safely using QDs in humans. Furthermore, different colored crystals can simultaneously carry out an array of therapeutic and imaging functions, depending on their surface polymers. The researchers believe that their ultrasound technique can be used to rapidly create and characterize the toxicity of other nanoparticles as well.

####

For more information, please click here

Copyright © Wiley-VCH Materials Science Journals

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

Link to the original paper on Wiley Online Library:

Related News Press

News and information

Springer and Tsinghua University Press present the second Nano Research Award: Paul Alivisatos of the University of California Berkeley receives the honor for outstanding contributions in nanoscience July 30th, 2015

European Technology Platform for Nanomedicine and ENATRANS European Consortium Launch the 2nd edition of the Nanomedicine Award: The Award to be presented at BIO-Europe conference in Munich, November 2015 July 30th, 2015

Take a trip through the brain July 30th, 2015

This could replace your silicon computer chips: A new semiconductor material made from black phosphorus may be a candidate to replace silicon in future tech July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Imaging

Take a trip through the brain July 30th, 2015

Nanomedicine

European Technology Platform for Nanomedicine and ENATRANS European Consortium Launch the 2nd edition of the Nanomedicine Award: The Award to be presented at BIO-Europe conference in Munich, November 2015 July 30th, 2015

Take a trip through the brain July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Newly-Developed Polymers Control Size of Nanoparticles during Production Process July 30th, 2015

Discoveries

Take a trip through the brain July 30th, 2015

This could replace your silicon computer chips: A new semiconductor material made from black phosphorus may be a candidate to replace silicon in future tech July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Controlling Dynamic Behavior of Carbon Nanosheets in Structures Made Possible July 30th, 2015

Announcements

Take a trip through the brain July 30th, 2015

This could replace your silicon computer chips: A new semiconductor material made from black phosphorus may be a candidate to replace silicon in future tech July 30th, 2015

Sol-gel capacitor dielectric offers record-high energy storage July 30th, 2015

Controlling Dynamic Behavior of Carbon Nanosheets in Structures Made Possible July 30th, 2015

Safety-Nanoparticles/Risk management

March 2016; 6th Int'l Conference on Nanostructures in Iran July 29th, 2015

Environmentally friendly lignin nanoparticle 'greens' silver nanobullet to battle bacteria July 13th, 2015

NIST ‘How-To’ Website Documents Procedures for Nano-EHS Research and Testing July 1st, 2015

Proposed TSCA Nanomaterial Rule ‘Premature’, Says Former EPA Toxicologist July 1st, 2015

Quantum Dots/Rods

Quantum networks: Back and forth are not equal distances! July 28th, 2015

Superfast fluorescence sets new speed record: Plasmonic device has speed and efficiency to serve optical computers July 27th, 2015

Engineered hybrid crystal opens new frontiers for high-efficiency lighting: University of Toronto researchers successfully combine 2 different materials to create new hyper-efficient light-emitting crystal July 16th, 2015

Down to the quantum dot: Jülich researchers develop ultrahigh-resolution 3-D microscopy technique for electric fields July 7th, 2015

NanoNews-Digest
The latest news from around the world, FREE



  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More











ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project