Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Quantum Dots May be Toxic to Cells, Environment Under Certain Conditions

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, the first to report on how different pH levels may affect the safety of QDs, appears in the Jan.15 issue of ACS’ Environmental Science & Technology, a semi-monthly journal.

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.”

“Quantum Dot Weathering Results in Microbial Toxicity”
Pedro J. Alvarez, Ph.D.
Rice University
Houston, Texas 77005
Phone: 713-348-5903
Fax: 713-348-5203

Michael Woods | Newswise Science News
Further information:

More articles from Ecology, The Environment and Conservation:

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

nachricht Malaysia's unique freshwater mussels in danger
27.09.2016 | The University of Nottingham Malaysia Campus

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>