Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Science provides new way to peer into pores

10.09.2015

Rice University lab finds technique to characterize nanoscale spaces in porous materials

Rice University scientists led a project to "see" and measure the space in porous materials, even if that space is too small or fragile for traditional microscopes.


The paths fluorescent particles take as they diffuse through a porous nanoscale structure reveal the arrangement of the pores through a technique developed by scientists at Rice University.

Credit: Landes Research Group/Rice University

The Rice lab of chemist Christy Landes invented a technique to characterize such nanoscale spaces, an important advance toward her group's ongoing project to efficiently separate "proteins of interest" for drug manufacture. It should also benefit the analysis of porous materials of all kinds, like liquid crystals, hydrogels, polymers and even biological substances like cytosol, the compartmentalized fluids in cells.

The research with collaborators at the University of California, Los Angeles (UCLA) and Kansas State University appears in the American Chemical Society journal ACS Nano.

It's easy to use a fluorescent chemical compound to tag, or "label," a material and take a picture of it, Landes said. "But what if the thing you want a picture of is mostly nothing? That's the problem we had to solve to understand what was going on in the separation material."

The team aims to improve protein separation in a process called chromatography, in which solutions flow through porous material in a column. Because different materials travel at different speeds, the components separate and can be purified.

"We learned that in agarose, a porous material used to separate proteins, the clustering of charges is very important," Landes said. While the protein project succeeded, "when we matched experimental data to our theory, there was something additional contributing to the separation that we couldn't explain."

The answer appeared to be with how charged particles like nanoscale ligands arranged themselves in the pores. "It was the only possible explanation," Landes said. "So we needed a way to image the pores."

Standard techniques like atomic force, X-ray and electron microscopy would require samples to be either frozen or dried. "That would either shrink or swell or change their structures," she said.

It occurred to the team to combine their experience with the Nobel Prize-winning super-resolution microscopy and fluorescence correlation spectroscopy techniques. Super-resolution microscopy is a way to see objects at resolutions below the diffraction limit, which restricts the viewing of things that are smaller than the wavelength of light directed at them.

Correlation spectroscopy is a way to measure fluorescent particles as they fluctuate. By crunching data collected via a combination of super-resolution microscopy and correlation spectroscopy, the researchers mapped slices of the material to see where charged particles tended to cluster.

The combined technique, which they call fcsSOFI (for "fluorescence correlation spectroscopy super-resolution optical fluctuation imaging"), measures fluorescent tags as they diffuse in the pores, which allows researchers to simultaneously characterize dimensions and dynamics within the pores. The lab tested its technique on both soft agarose hydrogels and lyotropic liquid crystals. Next, they plan to extend their mapping to three-dimensional spaces.

"We now have both pieces of our puzzle: We can see our proteins interacting with charges within our porous material, and we can measure the pores," Landes said. "This has direct relevance to the protein separation problem for the $100 billion pharmaceutical industry."

###

Co-authors of the paper are Rice alumnus Lydia Kisley and Rice graduate students Lawrence Tauzin and Bo Shuang; Rice Quantum Institute/Smalley-Curl Institute summer undergraduate student Rachel Brunetti of Scripps College, Claremont, Calif.; graduate student Xiyu Yi and Shimon Weiss, a professor of chemistry and biochemistry, at UCLA; and graduate student Alec Kirkeminde and Daniel Higgins, a professor of chemistry, at Kansas State.

The Welch Foundation, the National Science Foundation, the Willard Chair at UCLA and the Department of Energy supported the research.

Read the abstract at http://pubs.acs.org/doi/abs/10.1021/acsnano.5b03430

This news release can be found online at http://news.rice.edu/2015/09/09/science-provides-new-way-to-peer-into-pores/

Follow Rice News and Media Relations via Twitter @RiceUNews.

Related Materials:

Landes Research Group: http://www.lrg.rice.edu

Wiess School of Natural Sciences: http://naturalsciences.rice.edu

Images for download:

http://news.rice.edu/wp-content/uploads/2015/09/0914_POROUS-1-WEB.jpg

The paths fluorescent particles take as they diffuse through a porous nanoscale structure reveal the arrangement of the pores through a technique developed by scientists at Rice University. (Credit: Landes Research Group/Rice University)

http://news.rice.edu/wp-content/uploads/2015/09/0914_POROUS-2-WEB.jpg

Christy Landes

Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,888 undergraduates and 2,610 graduate students, Rice's undergraduate student-to-faculty ratio is 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice is ranked No. 1 for best quality of life and for lots of race/class interaction by the Princeton Review. Rice is also rated as a best value among private universities by Kiplinger's Personal Finance. To read "What they're saying about Rice," go here.

David Ruth
713-348-6327
david@rice.edu

Mike Williams
713-348-6728
mikewilliams@rice.edu

David Ruth | EurekAlert!

More articles from Materials Sciences:

nachricht Contacting the molecular world through graphene nanoribbons
19.02.2018 | Elhuyar Fundazioa

nachricht When Proteins Shake Hands
19.02.2018 | Friedrich-Schiller-Universität Jena

All articles from Materials Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: In best circles: First integrated circuit from self-assembled polymer

For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.

In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...

Im Focus: Demonstration of a single molecule piezoelectric effect

Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale

Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...

Im Focus: Hybrid optics bring color imaging using ultrathin metalenses into focus

For photographers and scientists, lenses are lifesavers. They reflect and refract light, making possible the imaging systems that drive discovery through the microscope and preserve history through cameras.

But today's glass-based lenses are bulky and resist miniaturization. Next-generation technologies, such as ultrathin cameras or tiny microscopes, require...

Im Focus: Stem cell divisions in the adult brain seen for the first time

Scientists from the University of Zurich have succeeded for the first time in tracking individual stem cells and their neuronal progeny over months within the intact adult brain. This study sheds light on how new neurons are produced throughout life.

The generation of new nerve cells was once thought to taper off at the end of embryonic development. However, recent research has shown that the adult brain...

Im Focus: Interference as a new method for cooling quantum devices

Theoretical physicists propose to use negative interference to control heat flow in quantum devices. Study published in Physical Review Letters

Quantum computer parts are sensitive and need to be cooled to very low temperatures. Their tiny size makes them particularly susceptible to a temperature...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

2nd International Conference on High Temperature Shape Memory Alloys (HTSMAs)

15.02.2018 | Event News

Aachen DC Grid Summit 2018

13.02.2018 | Event News

How Global Climate Policy Can Learn from the Energy Transition

12.02.2018 | Event News

 
Latest News

Contacting the molecular world through graphene nanoribbons

19.02.2018 | Materials Sciences

When Proteins Shake Hands

19.02.2018 | Materials Sciences

Cells communicate in a dynamic code

19.02.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>