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.

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 September 3, 2014 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 September 3, 2014).

Share This



More Earth & Climate News

Wednesday, September 3, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Thousands of Fish Dead in Mexico Lake

Raw: Thousands of Fish Dead in Mexico Lake

AP (Sep. 2, 2014) — Over 53 tons of rotting fish have been removed from Lake Cajititlan in western Jalisco state. Authorities say that the thousands of fish did not die of natural causes. (Sep. 2) Video provided by AP
Powered by NewsLook.com
Raw: Iceland Volcano Spewing Smoke

Raw: Iceland Volcano Spewing Smoke

AP (Sep. 2, 2014) — The alert warning for the area surrounding Iceland's Bardarbunga volcano was kept at orange on Tuesday, indicating increased unrest with greater potential for an eruption. Smoke is spewing from the volcano, and lava is spouting nearby. (Sept. 2) Video provided by AP
Powered by NewsLook.com
U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

U.N. Says Ebola Travel Restrictions Will Cause Food Shortage

Newsy (Sep. 2, 2014) — The U.N. says the problem is two-fold — quarantine zones and travel restrictions are limiting the movement of both people and food. Video provided by Newsy
Powered by NewsLook.com
Halliburton Reaches $1B Gulf Spill Settlement

Halliburton Reaches $1B Gulf Spill Settlement

AP (Sep. 2, 2014) — Halliburton's agreement to pay more than $1 billion to settle numerous claims involving the 2010 BP oil spill could be a way to diminish years of costly litigation. A federal judge still has to approve the settlement. (Sept. 2) Video provided by AP
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:
from the past week

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