Featured Research

from universities, journals, and other organizations

Quantum Dots May Be Toxic To Cells And Environment Under Certain Conditions

Date:
January 31, 2009
Source:
American Chemical Society
Summary:
Researchers in Texas are reporting that quantum dots (QDs) -- a product of the revolution in nanotechnology increasingly used in electronics, solar cells, and medical imaging devices -- may be toxic to cells under acidic or alkaline conditions. Their study is the first to report on how different pH levels may affect the safety of QDs.

Researchers in Texas are reporting that quantum dots (QDs) — a product of the revolution in nanotechnology increasingly used in electronics, solar cells, and medical imaging devices — may be toxic to cells under acidic or alkaline conditions. Their study is the first to report on how different pH levels may affect the safety of QDs.

Related Articles


In the new study, Pedro Alvarez, Shaily Mahendra, and colleagues note that QDs are semiconductor nanocrystals composed of a metal core surrounded by a shell composed of zinc or cadmium sulfide. Scientists are increasingly concerned that these submicroscopic dots, about 1/50,000th the width of a human hair, could decompose during normal use or after disposal. That decomposition could release toxic metals into the environment, posing a health risk to humans and animals.

To explore this concern, the scientists exposed two common types of bacteria that serve as models of cell toxicity and indicators of environmental health to QDs under different conditions of acidity and alkalinity. At near neutral pH levels, bacteria exposed to QDs experienced decreased rates of growth, but did not die.

However, at moderately acidic or alkaline conditions, many of the QD-exposed bacteria died as QDs shells decomposed, releasing their content of toxic metals. However, proteins and natural organic matter may be able to mitigate toxicity by complexing metal ions or coating particles.

The study cautions, “the release of toxic inorganic constituents during their weathering under acidic or alkaline conditions in the human body or the environment may cause unintended harm that might be difficult to predict with short-term toxicity tests.”


Story Source:

The above story is based on materials provided by American Chemical Society. Note: Materials may be edited for content and length.


Journal Reference:

  1. Mahendra et al. Quantum Dot Weathering Results in Microbial Toxicity. Environmental Science & Technology, Jan 15, 2009; 42 (24): 9424 DOI: 10.1021/es8023385

Cite This Page:

American Chemical Society. "Quantum Dots May Be Toxic To Cells And Environment Under Certain Conditions." ScienceDaily. ScienceDaily, 31 January 2009. <www.sciencedaily.com/releases/2009/01/090128214342.htm>.
American Chemical Society. (2009, January 31). Quantum Dots May Be Toxic To Cells And Environment Under Certain Conditions. ScienceDaily. Retrieved April 21, 2015 from www.sciencedaily.com/releases/2009/01/090128214342.htm
American Chemical Society. "Quantum Dots May Be Toxic To Cells And Environment Under Certain Conditions." ScienceDaily. www.sciencedaily.com/releases/2009/01/090128214342.htm (accessed April 21, 2015).

Share This


More From ScienceDaily



More Earth & Climate News

Tuesday, April 21, 2015

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Maine Storm Surge Sparks Power Explosions

Raw: Maine Storm Surge Sparks Power Explosions

AP (Apr. 21, 2015) — Police dash cam video shows a series of explosions along the beach in Maine as heavy storm surge soaked electrical transformers. (April 21) Video provided by AP
Powered by NewsLook.com
Searching For The Loch Ness Monster? Try Google Street View

Searching For The Loch Ness Monster? Try Google Street View

Newsy (Apr. 21, 2015) — For the anniversary of the notorious "Surgeon&apos;s Photo" of the Loch Ness monster, Google used Street View to let those online join the search. Video provided by Newsy
Powered by NewsLook.com
Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

Going Ape: Sierra Leone Chimpanzees Hail Ebola Retreat

AFP (Apr. 21, 2015) — As money runs out at Tacugama Chimpanzee Sanctuary in Sierra Leone, around 85 chimps are facing homelessness. The centre closed when the Ebola epidemic was ravaging the country but now that closure is beginning to look permanent. Video provided by AFP
Powered by NewsLook.com
Solar Plane Completes 6th Leg of Quest to Circumnavigate Globe

Solar Plane Completes 6th Leg of Quest to Circumnavigate Globe

AFP (Apr. 21, 2015) — Solar Impulse 2 lands in the Chinese city of Nanjing, finishing the sixth stage of its landmark 12-leg quest to circumnavigate the globe powered only by the sun. Duration: 00:42 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Plants & Animals

Earth & Climate

Fossils & Ruins

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins