Navigation Links
Improved characterization of nanoparticle clusters for EHS and biosensors research
Date:10/26/2011

The tendency of nanoparticles to clump together in solution"agglomeration"is of great interest because the size of the clusters plays an important role in the behavior of the materials. Toxicity, the persistence of the nanomaterials in the environment, their efficacy as biosensors and, for that matter, the accuracy of experiments to measure these factors, are all known to be affected by agglomeration and cluster size. Recent work* at the National Institute of Standards and Technology (NIST) offers a way to measure accurately both the distribution of cluster sizes in a sample and the characteristic light absorption for each size. The latter is important for the application of nanoparticles in biosensors.

A good example of the potential application of the work, says NIST biomedical engineer Justin Zook, is in the development of nanoparticle biosensors for ultrasensitive pregnancy tests. Gold nanoparticles can be coated with antibodies to a hormone** produced by an embryo shortly after conception. Multiple gold nanoparticles can bind to each hormone, forming clusters that have a different color from unclustered gold nanoparticles. But only certain size clusters are optimal for this measurement, so knowing how light absorbance changes with cluster size makes it easier to design the biosensors to result in just the right sized clusters.

The NIST team first prepared samples of gold nanoparticlesa nanomaterial widely used in biologyin a standard cell culture solution, using their previously developed technique for creating samples with a controlled distribution of sizes***. The particles are allowed to agglomerate in gradually growing clusters and the clumping process is "turned off" after varying lengths of time by adding a stabilizing agent that prevents further agglomeration.

They then used a technique called analytical ultracentrifugation (AUC) to simultaneously sort the clusters by size and measure their light absorption. The centrifuge causes the nanoparticle clusters to separate by size, the smaller, lighter clusters moving more slowly than the larger ones. While this is happening, the sample containers are repeatedly scanned with light and the amount of light passing through the sample for each color or frequency is recorded. The larger the cluster, the more light is absorbed by lower frequencies. Measuring the absorption by frequency across the sample containers allows the researchers both to watch the gradual separation of cluster sizes and to correlate absorbed frequencies with specific cluster sizes.

Most previous measurements of absorption spectra for solutions of nanoparticles were able only to measure the bulk spectrathe absorption of all the different cluster sizes mixed together. AUC makes it possible to measure the quantity and distribution of each nanoparticle cluster without being confounded by other components in complex biological mixtures, such as proteins. The technique previously had been used only to make these measurements for single nanoparticles in solution. The NIST researchers are the first to show that the procedure also works for nanoparticle clusters.


'/>"/>

Contact: Michael E. Newman
michael.newman@nist.gov
301-975-3025
National Institute of Standards and Technology (NIST)
Source:Eurekalert  

Related biology news :

1. Improved living environments can reduce health problems for women and children
2. Breeding soybeans for improved feed
3. First proof in patients of an improved magic bullet for cancer detection and radio-therapy
4. Improved method for capturing proteins holds promise for biomedical research
5. U of M researchers use improved imaging technique; discover a better approach to diagnosing epilepsy
6. Trastuzumab and chemotherapy improved survival in HER2-postive breast and brain cancer patients
7. New genetic map of potato may lead to improved crops
8. Nanowire-based sensors offer improved detection of volatile organic compounds
9. China needs improved administrative system for nuclear power safety
10. IOF calls for improved strategies to close the treatment gap and reduce future burden of fractures
11. NPL helps Senceive to offer improved monitoring of structural assets across the UK
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Improved characterization of nanoparticle clusters for EHS and biosensors research
(Date:6/3/2016)... 3, 2016 Das ... Nepal hat ein 44 ... geprägter Kennzeichen, einschließlich Personalisierung, Registrierung und IT-Infrastruktur, ... Produktion und Implementierung von Identitätsmanagementlösungen. Zahlreiche renommierte ... Januar teilgenommen, aber Decatur wurde als konformste ...
(Date:5/24/2016)... Ampronix facilitates superior patient care by providing unparalleled technology to leaders of the medical ... premium product recently added to the range of products distributed by Ampronix. ... ... ... Ampronix News ...
(Date:5/3/2016)...  Neurotechnology, a provider of high-precision biometric identification ... Identification System (ABIS) , a complete system for ... can process multiple complex biometric transactions with high ... face or iris biometrics. It leverages the core ... MegaMatcher Accelerator , which have been used in ...
Breaking Biology News(10 mins):
(Date:6/24/2016)... DIEGO , June 24, 2016 ... more sensitively detects cancers susceptible to PARP inhibitors ... circulating tumor cells (CTCs). The new test has ... HRD-targeted therapeutics in multiple cancer types. ... targeting DNA damage response pathways, including PARP, ATM, ...
(Date:6/23/2016)... ... June 23, 2016 , ... ... to announce the launch of their brand, UP4™ Probiotics, into Target stores nationwide. ... years, is proud to add Target to its list of well-respected retailers. This ...
(Date:6/23/2016)... , June 23, 2016 Houston Methodist ... the Cy-Fair Sports Association to serve as their ... agreement, Houston Methodist Willowbrook will provide sponsorship support, ... connectivity with association coaches, volunteers, athletes and families. ... the Cy-Fair Sports Association and to bring Houston ...
(Date:6/23/2016)...   EpiBiome , a precision microbiome engineering company, ... financing from Silicon Valley Bank (SVB). The financing will ... its drug development efforts, as well as purchase additional ... has been an incredible strategic partner to us – ... would provide," said Dr. Aeron Tynes Hammack , ...
Breaking Biology Technology: