Nanotechnology Now







Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Arsenic and Gold Clusters

Low level: The amount of arsenic in Bangladeshi well water and in bottled drinking water and Mississippi tap water are indicated by a dynamic light scattering (DLS) assay. Label-free gold nanoparticles are used in a selective colorimetric assay (see picture) and in a highly sensitive DLS assay for the recognition of arsenic in concentrations as low as 3 ppt.
Low level: The amount of arsenic in Bangladeshi well water and in bottled drinking water and Mississippi tap water are indicated by a dynamic light scattering (DLS) assay. Label-free gold nanoparticles are used in a selective colorimetric assay (see picture) and in a highly sensitive DLS assay for the recognition of arsenic in concentrations as low as 3 ppt.

Abstract:
Fast, easy, and highly sensitive arsenic detection with gold nanoparticles

Arsenic and Gold Clusters

Jackson, MI | Posted on November 25th, 2009

Mention of arsenic poisoning usually brings to mind underhanded murder. However, the danger of arsenic poisoning from contaminated drinking water is far greater. Low concentrations of arsenic are found in nearly all soils and thus also in ground water. About 140 million people worldwide possibly drink water that contains arsenic concentrations above the WHO-recommended limit of 10 ppb (parts per billion). Researchers at Jackson State University (MS, USA) have now developed a new approach for a rapid, easy, and highly sensitive arsenic test. As Paresh Chandra Ray's team reports in the journal Angewandte Chemie, their method is based on the aggregation of gold nanoparticles, and it selectively detects arsenic in drinking water down to concentrations of 3 ppt (parts per trillion).

Countries like India, Bangladesh, and Thailand are primarily affected by ground water with high arsenic concentrations. However, high concentrations of arsenic have also been found in some areas of North and South America. Once detected, the problem can fairly easily be addressed. Current analytical techniques are time-consuming and require a series of enrichment steps.

The new process could now speed up and simplify arsenic analysis. The scientists working with Ray have attached special organic molecules to the surfaces of gold nanoparticles. These molecules act as "ligands" for arsenic, meaning that they form a complex with it. Each arsenic ion can bind to three ligands, which allows it to link together up to three gold particles. The higher the arsenic concentration in the sample, the more strongly the gold particles clump together and the number of bigger aggregates increases. The color of gold nanoparticles in a liquid depends on their size. Whereas the arsenic-free gold nanoparticles appear red, arsenic-induced aggregation causes the color to change to blue. Concentrations down to 1 ppb can be detected with the naked eye by means of the color change. Arsenic binds to the ligands much more strongly than other metals; the researchers were able to increase this selectivity by attaching three different ligands to the gold.

One very precise method for detecting minimal changes in particle size is dynamic light scattering (DLS), in which laser light scattered by the particles is analyzed. By using DLS, Ray and his co-workers were able to detect and quantify arsenic concentrations as low as 3 ppt. In samples of well water from Bangladesh, the team found 28 ppb arsenic; in water from taps in Jackson (Mississippi, USA) they found 380 ppt.

Author: Paresh Chandra Ray, Jackson State University (USA), chem.jsums.edu/ray/

Title: Use of Gold Nanoparticles in a Simple Colorimetric and Ultrasensitive Dynamic Light Scattering Assay: Selective Detection of Arsenic in Groundwater

Angewandte Chemie International Edition 2009, 48, No. 51, 9668-9671, doi: 10.1002/anie.200903958

####

For more information, please click here

Copyright © Angewandte Chemie

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 News Press

News and information

Protein Building Blocks for Nanosystems: Scientists develop method for producing bio-based materials with new properties April 17th, 2015

Oxford Instruments commissions high field outsert magnet system for the National High Magnetic Field Laboratory 32 Tesla magnet program April 17th, 2015

QD Vision Expands Product Line with Two-Millimeter Color LCD Display Optic: Color IQ™ Optic Enables Full-Color Gamut for Ultra-Thin Displays and All-in-One Computers April 16th, 2015

The National Science Foundation names engineering researcher Andrea Alú its Alan T. Waterman awardee for 2015: Alú is a pioneer in the field of metamaterials who has developed "cloaking" technology to make objects invisible to sensors April 16th, 2015

Possible Futures

A glass fiber that brings light to a standstill: By coupling photons to atoms, light in a glass fiber can be slowed down to the speed of an express train; for a short while it can even be brought to a complete stop April 9th, 2015

Nanotechnology in Medical Devices Market is expected to reach $8.5 Billion by 2019 March 25th, 2015

Nanotechnology Enabled Drug Delivery to Influence Future Diagnosis and Treatments of Diseases March 21st, 2015

Nanocomposites Market Growth, Industry Outlook To 2020 by Grand View Research, Inc. March 21st, 2015

Sensors

MIT sensor detects spoiled meat: Tiny device could be incorporated into 'smart packaging' to improve food safety April 15th, 2015

Graphene pushes the speed limit of light-to-electricity conversion: Researchers from ICFO, MIT and UC Riverside have been able to develop a graphene-based photodetector capable of converting absorbed light into an electrical voltage at ultrafast timescales April 14th, 2015

Iranian Scientists Evaluate Dynamic Interaction between 2 Carbon Nanotubes April 14th, 2015

New Biosensor Increases Possibility to Predict Potential of Heart Diseases April 12th, 2015

Announcements

Protein Building Blocks for Nanosystems: Scientists develop method for producing bio-based materials with new properties April 17th, 2015

Oxford Instruments commissions high field outsert magnet system for the National High Magnetic Field Laboratory 32 Tesla magnet program April 17th, 2015

Newly-Developed Nanocatalysts Increase Performance of Fuel Cells April 16th, 2015

Lanthanide-Organic Framework Nanothermometers Prepared by Spray-Drying April 16th, 2015

Environment

Young NTU Singapore spin-off clinches S$4.3 million joint venture with Chinese commercial giant March 23rd, 2015

New processing technology converts packing peanuts to battery components March 22nd, 2015

EU Funded PCATDES Project has completed its half-period with success March 19th, 2015

Are current water treatment methods sufficient to remove harmful engineered nanoparticle? March 10th, 2015

Water

Iranian Scientists Produce Magnetic Recyclable Photocatalyst to Purify Polluted Water April 8th, 2015

Water makes wires even more nano: Rice University lab extends meniscus-mask process to make sub-10 nanometer paths April 6th, 2015

Square ice filling for a graphene sandwich March 26th, 2015

ORNL-led team demonstrates desalination with nanoporous graphene membrane March 25th, 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







© Copyright 1999-2015 7th Wave, Inc. All Rights Reserved PRIVACY POLICY :: CONTACT US :: STATS :: SITE MAP :: ADVERTISE