Nanotechnology Now

Our NanoNews Digest Sponsors


Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > A giant step in a miniature world: UZH researcher measures the electrical charge of nano particles

This is a cross-section through two chip-sized glass plates in which a nano particle is trapped in an energy hole (or “potential well” to use the scientific term). The colored fields show the different charges in the electrostatic field. The red zone signifies a very low charge, while the blue edges have a strong charge.

Credit: Picture: University of Zurich
This is a cross-section through two chip-sized glass plates in which a nano particle is trapped in an energy hole (or “potential well” to use the scientific term). The colored fields show the different charges in the electrostatic field. The red zone signifies a very low charge, while the blue edges have a strong charge.

Credit: Picture: University of Zurich

Abstract:
In order to observe the individual particles in a solution, Prof. Madhavi Krishnan and her co-workers «entice» each particle into an «electrostatic trap». It works like this: between two glass plates the size of a chip, the researchers create thousands of round energy holes. The trick is that these holes have just a weak electrostatic charge. The scientists than add a drop of the solution to the plates, whereupon each particle falls into an energy hole and remains trapped there. But the particles do not remain motionless in their trap. Instead, molecules in the solution collide with them continuously, causing the particles to move in a circular motion. «We measure these movements, and are then able to determine the charge of each individual particle», explains Prof. Madhavi Krishnan.

A giant step in a miniature world: UZH researcher measures the electrical charge of nano particles

Zurich, Switzerland | Posted on July 30th, 2012

Put simply, particles with just a small charge make large circular movements in their traps, while those with a high charge move in small circles. This phenomenon can be compared to that of a light-weight ball which, when thrown, travels further than a heavy one. The US physicist Robert A. Millikan used a similar method 100 years ago in his oil drop experiment to determine the velocity of electrically charged oil drops. In 1923, he received the Nobel Prize in physics in recognition of his achievements. «But he examined the drops in a vacuum», Prof. Krishnan explains. «We on the other hand are examining nano particles in a solution which itself influences the properties of the particles».

Electrostatic charge of «nano drugs packages»

For all solutions manufactured industrially, the electrical charge of the nano particles contained therein is also of primary interest, because it is the electrical charge that allows a fluid solution to remain stable and not to develop a lumpy consistency. «With our new method, we get a picture of the entire suspension along with all of the particles contained in it», emphasizes Prof. Madhavi Krishnan. A suspension is a fluid in which miniscule particles or drops are finely distributed, for example in milk, blood, various paints, cosmetics, vaccines and numerous pharmaceuticals. «The charge of the particles plays a major role in this», the Zurich-based scientist tells us.

One example is the manufacture of medicines that have to be administered in precise doses over a longer period using drug-delivery systems. In this context, nano particles act as «packages» that transport the drugs to where they need to take effect. Very often, it is their electrical charge that allows them to pass through tissue and cell membranes in the body unobstructed and so to take effect. «That's why it is so important to be able to measure their charge. So far most of the results obtained have been imprecise», the researcher tells us.

«The new method allows us to even measure in real-time a change in the charge of a single entity», adds Prof. Madhavi Krishnan. «This is particularly exciting for basic research and has never before been possible». This is because changes in charge play a role in all bodily reactions, whether in proteins, large molecules such as the DNA double helix, where genetic make-up is encoded, or cell organelles. «We're examining how material works in the field of millionths of a millimeter».

####

For more information, please click here

Contacts:
Prof. Dr. Madhavi Krishnan
Universität Zürich
Physikalisch-chemisches Institut
Phone: +41 44 635 44 65
madhavi.krishnan@ uzh.ch

Copyright © University of Zurich

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 Links

Literature: Mojarad, N, and Krishnan, M., Measuring the size and charge of single nanoscale objects in solution using an electrostatic fluidic trap. Nature Nanotechnology (2012)

Related News Press

News and information

Animal study shows flexible, dissolvable silicon device promising for brain monitoring: Other applications include post-operative observation for vascular, cardiac, and orthopaedic procedures, finds Penn study May 5th, 2016

Speedy ion conduction in solid electrolytes clears road for advanced energy devices May 5th, 2016

Engineers create a better way to boil water -- with industrial, electronics applications May 5th, 2016

Clues on the path to a new lithium battery technology: Charging produces highly reactive singlet oxygen in lithium air batteries May 5th, 2016

Imaging

Oxford Instruments Asylum Research and McGill University Announce the McGill AFM Summer School and Workshop, May 12-13, 2016 May 4th, 2016

The intermediates in a chemical reaction photographed 'red-handed' Researchers at the UPV/EHU-University of the Basque Country have for the first time succeeded in imaging all the steps in a complex organic reaction and have resolved the mechanisms that explain it May 4th, 2016

New tool allows scientists to visualize 'nanoscale' processes May 4th, 2016

FEI Launches Apreo – Industry-Leading Versatile, High-Performance SEM: The Apreo SEM provides high-resolution surface information with excellent contrast, and the flexibility to accommodate a large range of samples, applications and conditions May 4th, 2016

Nanomedicine

Animal study shows flexible, dissolvable silicon device promising for brain monitoring: Other applications include post-operative observation for vascular, cardiac, and orthopaedic procedures, finds Penn study May 5th, 2016

Unique nano-capsules promise the targeted drug delivery: Russian scientists created unique nano-capsules for the targeted drug delivery May 5th, 2016

The intermediates in a chemical reaction photographed 'red-handed' Researchers at the UPV/EHU-University of the Basque Country have for the first time succeeded in imaging all the steps in a complex organic reaction and have resolved the mechanisms that explain it May 4th, 2016

Nuclear pores captured on film: Using an ultra fast-scanning atomic force microscope, researchers from the University of Basel have filmed 'living' nuclear pore complexes at work for the first time May 3rd, 2016

Discoveries

Animal study shows flexible, dissolvable silicon device promising for brain monitoring: Other applications include post-operative observation for vascular, cardiac, and orthopaedic procedures, finds Penn study May 5th, 2016

Speedy ion conduction in solid electrolytes clears road for advanced energy devices May 5th, 2016

Engineers create a better way to boil water -- with industrial, electronics applications May 5th, 2016

Unique nano-capsules promise the targeted drug delivery: Russian scientists created unique nano-capsules for the targeted drug delivery May 5th, 2016

Announcements

Speedy ion conduction in solid electrolytes clears road for advanced energy devices May 5th, 2016

Engineers create a better way to boil water -- with industrial, electronics applications May 5th, 2016

Clues on the path to a new lithium battery technology: Charging produces highly reactive singlet oxygen in lithium air batteries May 5th, 2016

Unique nano-capsules promise the targeted drug delivery: Russian scientists created unique nano-capsules for the targeted drug delivery May 5th, 2016

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







Car Brands
Buy website traffic