Archive for the ‘Chemistry World Highlights’ Category

Finding a synthetic nanoparticle in a haystack

New analytical approach can detect engineered nanoparticles in the environment

Autumn plowed fields farm house

Source: © Shutterstock

Scientists from Austria and Switzerland have developed a new way to distinguish engineered nanoparticles from naturally occurring nanoscale particles in soil samples. The method works even at concentrations orders of magnitude below natural background levels.

Everyday items, such as cosmetics and textiles, increasingly contain nanoparticles. Concerns regarding nanoparticles’ potential impact on health and the environment mean regulators want to monitor synthetic nanoparticle (for example TiO2, SiO2 and CeO2) levels in the environment. However, samples often contain natural nanoparticles of similar size and composition, often at much higher concentrations. Conventional single-particle inductively coupled plasma mass spectrometry (spICP-MS), where the instrument locks onto one isotope, is unable to tell them apart.

 

After working in the area for several years, Frank von der Kammer and Thilo Hofmannfrom the University of Vienna and co-workers have now made a breakthrough based on multi-elemental fingerprinting to explore differences, such as elemental ratio, between engineered and natural nanoparticles. The team tested the concept using an instrument, developed by colleagues at the Swiss Federal Institute of Technology (ETH) in Zurich, that enables single particle analysis on a time-of-flight mass spectrometer (TOFMS). The prototype spICP-TOFMS instrument is so fast, it not only measures all of the different elements simultaneously, it does so for every particle. They then developed a machine-learning algorithm to train the analytical system, using well-defined standards of both types of nanoparticles, to increase the speed and precision of the analysis.

 

Read the full article in Chemistry World.


Single-particle multi-element fingerprinting (spMEF) using inductively-coupled plasma time-of-flight mass spectrometry (ICP-TOFMS) to identify engineered nanoparticles against the elevated natural background in soils
Antonia Praetorius, Alexander Gundlach-Graham, Eli Goldberg, Willi Fabienke, Jana Navratilova, Andreas Gondikas, Ralf Kaegi, Detlef Günther, Thilo Hofmann and Frank von der Kammer
Environ. Sci.: Nano, 2017
DOI: 10.1039/C6EN00455E

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Metal-guzzling plants harvested to make nanomaterials

Vegetation that cleanses contaminated soil adds to its virtues

 

Brassica juncea

Brassica juncea, a type of mustard plant, absorbs heavy metals through its roots. Source: © iStock

Plants partial to a diet of heavy metals are an ideal raw material for nanomaterials once they have cleaned up contaminated soil. So says a team of Chinese scientists behind a method that turns this vegetation into nanoparticles and nanotubes.

 

Heavy metals are naturally occurring elements with important industrial, agricultural and technological uses. Many human activities such as mining and industry lead to the local build-up of toxic heavy metals in soil and groundwater. Typically toxic and carcinogenic, their release into the environment is a major concern as they can accumulate in the food chain, damaging the health of wildlife and humans alike.

 

Certain plant species known as hyperaccumulators can grow in soil contaminated with heavy metals. They absorb the metals through their roots and concentrate them in their own tissues – a genetic trait designed to make themselves toxic to hungry herbivores. These plants have been used in the past to clean up contaminated areas; a technique called phytoremediation. Once the plants have extracted the metals, they themselves need to be removed, as if left to complete their natural lifecycle they would simply return the metals to the soil. The metal-containing plant waste is often incinerated.

 

Now, Jiao Qu and his team at Northeast Normal University in China have used this biomass as a raw material to make useful nanomaterials.

 

Read the full article in Chemistry World.


A cost-effective method for recycling carbon and metals in plants: synthesizing nanomaterials
Haiyang Liu, Miao Ren, Jiao Qu, Yue Feng, Xiangmeng Song, Qian Zhang, Qiao Cong and Xing Yuan
Environ. Sci.: Nano, 2017
DOI: 10.1039/C6EN00287K

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Miracle material potential water pollutant

Researchers demonstrate toxic effects of graphene on aquatic life

By looking at the effects of graphene on water fleas, scientists in China have discovered that it may disrupt aquatic ecosystems, suggesting an unfortunate dark side to the wonder material.

Graphene, the poster child of carbon nanomaterials, has been extensively studied in recent years, and has shown great promise in fields ranging from materials chemistry to electronics and medicine. However, until now its toxicity to aquatic organisms has not been a serious concern.

Wenhong Fan and his team at Beihang University suspended a range of carbon nanomaterials in water and observed their effects on daphnids, also called water fleas, a model organism for water pollution tests. At concentrations above 0.5mg/l graphene significantly impaired their growth and reproduction over a period of 21 days. Fan speculates this is caused by adsorption of graphene onto the daphnids’ surface. Other carbon nanomaterials, including buckminsterfullerene, single walled carbon nanotubes and multi-walled carbon nanotubes, proved more benign.

After 21 days in contaminated water, the daphnids were covered in graphene (far right, GN). Other materials (fullerenes/C60, single-walled carbon nanotubes/SWCNT, multi-walled carbon nanotubes/MWCNT) were barely adsorbed. Source: © Royal Society of Chemistry

Read the full article in Chemistry World.


The mechanism of chronic toxicity to Daphnia magna induced by graphene suspended in a water column

Wenhong Fan, Yingying Liu, Zhizhen Xu, Xiangrui Wang, Xiaomin Li and Shenglian Luo

Environ. Sci.: Nano, 2016, Advance Article

DOI: 10.1039/C6EN00361C, Paper

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

What’s your nano poison?

Informatics tool helps researchers visualise complex toxicity datasets

To help predict and avoid designing toxic nanomaterials, researchers have created an informatics tool that can pull out and visualise key information from a large collection of complex nanomaterials research.

Nanomaterials are now common in commercial products such as clothing and cleaning agents, and the amount of research into potential adverse environmental and health effects has increased exponentially. However, there is no comprehensive way to compare, or visualise, this information that could help researchers find correlations between nanomaterial properties and their toxicity. As well as the sheer volume of information, different studies also often consider different experimental conditions and biological material, making it very difficult to compare data directly.

Now, Sandra Karcher at Carnegie Mellon University, US, and her team have designed N4mics, a tool that can visualise nanoparticle toxicity research on zebrafish stored in the Nanomaterial-Biological Interactions Knowledgebase. Karcher says: ‘We developed the tool as a testbed to demonstrate how data that are standardised and shared can be mined to create visual comparisons between nanomaterial types. These visualisations are then used to generate novel hypotheses about how the properties of those materials affect their toxicity potential.’

Read the full article in Chemistry World.


Visualization tool for correlating nanomaterial properties and biological responses in zebrafish

Sandra C. Karcher, Bryan J. Harper, Stacey L. Harper, Christine Ogilvie Hendren, Mark R. Wiesner and Gregory V. Lowry

Environ. Sci.: Nano, 2016, Advance Article

DOI: 10.1039/C6EN00273K, Paper

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Nanomaterial recycling goes for gold

Researchers recover and reuse waste gold nanoparticles

Gold-cyclodextrin complex

The gold–cyclodextrin complex precipitates out of the recycling solution and can easily be filtered. Source: © Royal Society of Chemistry

A group of US chemists has developed a straightforward method to recover and recycle gold nanoparticles from nanomaterials waste.1

The market share for gold nanoparticles is expected to increase exponentially in the next years, as they have applications in areas like medical diagnostics, storage devices and solar cells. Gold is expensive, and researchers have been developing ways to recover gold from waste. However, most methods require toxic chemicals such as mercury or cyanide.

Now, a team led by Peter Vikesland at Virginia Tech in the US has adapted a gold recovery method first developed by recent Nobel prize laureate Sir Fraser Stoddart2 to capture gold nanoparticles from waste.

Read the full article in Chemistry World.


Waste not want not: life cycle implications of gold recovery and recycling from nanowaste

Paramjeet Pati, Sean McGinnis and Peter J. Vikesland

Environ. Sci.: Nano, 2016, 3, 1133-1143

DOI: 10.1039/C6EN00181E, Paper

From themed collection Sustainable Nanotechnology Organization

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Radioactive technetium waste tinned

Tin nanocomposite mops up nuclear waste contaminant.

Scientists have developed a tin-containing material that captures and stores radioactive technetium.

Scanning electron microscopy images show the tin-aluminophosphate’s structural change after exposure (right) to pertechnetate. Source: © Royal Society of Chemistry

Pertechnetate (99TcO4-) is a splitting product of uranium-235 and plutonium-239 and a radioactive nuclear waste contaminant. Technetium’s 213,000-year-long half-life and pertechnetate’s high solubility in water mean that the radioactive element can contaminate water supplies, enter the food chain and accumulate in animals’ and humans’ vital organs. Cold war activities and the Manhattan Project generated 99Tc in high quantities, and nuclear reactors as well as the Sellafield plant used to release this radioactive contaminant.

Tatiana Levitskaia, Sayandev Chatterjee and their team at the Pacific Northwest National Laboratory, US, have now synthesised a tin-aluminium-phosphate nanocomposite that removes and captures technetium from nuclear waste. The material reduces pertechnetate to the less water soluble Tc(IV), and at the same time changes its structure to capture and retain the reduced technetium.

Read the full article in Chemistry World.


Inorganic tin aluminophosphate nanocomposite for reductive separation of pertechnetate

Tatiana G. Levitskaia, Sayandev Chatterjee, Natasha K. Pence, Jesus Romero, Tamas Varga, Mark H. Engelhard, Yingge Du, Libor Kovarik, Bruce W. Arey, Mark E. Bowden and Eric D. Walter

Environ. Sci.: Nano, 2016, Advance Article

DOI: 10.1039/C6EN00130K, Paper

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Metal micronutrients get to the root of antifungal defence

Flavoursome tomato varieties could benefit from nanoparticle fertilisers.

heirloom tomato

Tasty heirloom tomato varieties could soon see a return to our plates thanks to the promising antifungal properties of metal oxide nanoparticle fertilisers developed by US scientists.

Centuries of plant breeding mean we’ve grown accustomed to a narrow range of crops bred primarily for their disease resistance. But while we reap the benefits of greater yields and reliability, we’re missing out on a host of different flavours from less disease-hardy varieties.

Now a nanoparticle crop treatment developed by Wade Elmer and Jason White at Connecticut Agricultural Experiment Station, US, could give older tomato varieties – more susceptible to root pathogens such as wilt fungus – a helping hand. Applying copper and manganese oxide nanoparticles to the leaves of tomato plants grown in soil infected with the Verticillium wilt fungus increased fruit yields by up to 33% compared with untreated plants.

Read the full article in Chemistry World.


Wade H. Elmer and Jason C. White
Environ. Sci.: Nano, 2016, Advance Article
DOI: 10.1039/C6EN00146G, Paper
Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Silver nanoparticles lost in the first wash

Scientists in Switzerland have discovered that more silver nanoparticles in clothing are released the first time they are washed than when they are sent to landfill.

Manufacturers add nanosilver to textiles to kill odour-causing bacteria © Shutterstock

Nanosilver’s antimicrobial properties often see it added to textiles, including socks and sportswear. Making, washing and disposing of the clothing can release the silver into the environment. Despite posing a low risk to humans, silver ions are toxic to many aquatic organisms and can accumulate in the food chain.

Commenting on the work, Amro El Badawy, an environmental engineer at California Polytechnic University, US, says:  ‘Deciphering the mechanisms of transformations of nanomaterials under the experimental conditions is key to our ability to predict any environmental implications – this work gets us closer to achieving this goal.’

Read the full ChemistryWorld article here.

Durability of nano-enhanced textiles through the life cycle: releases from landfilling after washing*
Denise M Mitrano, Pawena Limpiteeprakan, Sandhya Babel and Bernd Nowack
Environ. Sci.: Nano
, 2016, Accepted Manuscript
DOI:
10.1039/C6EN00023A

*Access is free through a registered RSC account until 11 May 2016 – click here to register

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)

Nanoparticle studies leave the lab

Scientists have gone beyond laboratory based experiments and have used a mesocosm to accurately study the fate of single walled carbon nanotubes (SWNTs) in wetland ecosystems, showing that SWNTs accumulate and persist in aquatic sediments.

Lee Ferguson and his team constructed a wetland mesocosm to examine the fate of carbon nanotubes in the aquatic environment © Pratt School of Engineering at Duke University, US

Single walled carbon nanotubes are an intriguing class of nanoparticle, and their unique properties have led to their use in a wide variety of applications, ranging from microelectronics to energy storage and even drug delivery. However, the impact of SWNTs on the environment is not fully understood. As the use of SWNTs in industry increases, environmental contamination due to spills of SWNT-containing waste or weathering of SWNT-containing products becomes ever more likely, and so the importance of studies focusing on the fate of SWNTs in the environment is growing.

To read the full article, please visit Chemistry World.

Download the full article for free*:

Fate of single walled carbon nanotubes in wetland ecosystems
Ariette Schierz, Benjamin Espinasse, Mark R. Wiesner, Joseph H. Bisesi, Tara Sabo-Attwood and P. Lee Ferguson
DOI: 10.1039/C4EN00063C, Paper

* Access is free through a registered RSC account – click here to register

Digg This
Reddit This
Stumble Now!
Share on Facebook
Bookmark this on Delicious
Share on LinkedIn
Bookmark this on Technorati
Post on Twitter
Google Buzz (aka. Google Reader)