Nanotechnology Now

Our NanoNews Digest Sponsors

Heifer International

Wikipedia Affiliate Button

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

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

New TriboLab CMP Provides Cost-Effective Characterization of Chemical Mechanical Wafer Polishing Processes: Bruker Updates Industry-Standard CP-4 Platform for Most Flexible and Reliable Testing June 27th, 2017

Imaging

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Nanomedicine

Physicists make quantum leap in understanding life's nanoscale machinery June 27th, 2017

Researchers developed nanoparticle based contrast agent for dual modal imaging of cancer June 21st, 2017

Learning with light: New system allows optical “deep learning”: Neural networks could be implemented more quickly using new photonic technology June 12th, 2017

Mussels add muscle to biocompatible fibers: Rice University chemists develop hydrogel strings using compound found in sea creatures June 9th, 2017

Discoveries

Physicists make quantum leap in understanding life's nanoscale machinery June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Atomic imperfections move quantum communication network closer to reality June 25th, 2017

Research accelerates quest for quicker, longer-lasting electronics: UC Riverside-led research makes topological insulators magnetic well above room temperatures June 25th, 2017

Announcements

Bosch announces high-performance MEMS acceleration sensors for wearables June 27th, 2017

Nanometrics to Participate in the 9th Annual CEO Investor Summit 2017: Accredited investor and publishing research analyst event held concurrently with SEMICON West and Intersolar 2017 in San Francisco June 27th, 2017

NMRC, University of Nottingham chooses the Quorum Q150 coater for its reliable and reproducible film thickness when coating samples with iridium June 27th, 2017

Picosun’s ALD solutions enable novel high-speed memories June 27th, 2017

Safety-Nanoparticles/Risk management

Tests show no nanotubes released during utilisation of nanoaugmented materials June 9th, 2017

NanoMONITOR shares its latest developments concerning the NanoMONITOR Software and the Monitoring stations April 21st, 2017

NIST updates 'sweet' 1950s separation method to clean nanoparticles from organisms January 27th, 2017

Nanoparticle exposure can awaken dormant viruses in the lungs January 17th, 2017

Quantum Dots/Rods

Graphene and quantum dots put in motion a CMOS-integrated camera that can see the invisible May 29th, 2017

The brighter side of twisted polymers: Conjugated polymers designed with a twist produce tiny, brightly fluorescent particles with broad applications May 16th, 2017

Nanoparticles open new window for biological imaging: “Quantum dots” that emit infrared light enable highly detailed images of internal body structures April 10th, 2017

Particle Works creates range of high performance quantum dots February 23rd, 2017

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