Oil-and-water approach from Richmond's UO lab to spark new line of versatile peptoid nanosheets
Scientists, including University of Oregon chemist Geraldine Richmond, have tapped oil and water to create scaffolds of self-assembling, synthetic proteins called peptoid nanosheets that mimic complex biological mechanisms and processes.
The accomplishment -- detailed this week in a paper placed online ahead of print by the Proceedings of the National Academy of Sciences -- is expected to fuel an alternative design of the two-dimensional peptoid nanosheets that can be used in a broad range of applications. Among them could be improved chemical sensors and separators, and safer, more effective drug-delivery vehicles.
Study co-author Ronald Zuckermann of the Molecular Foundry at Lawrence Berkeley National Laboratory (LBNL) first developed these ultra-thin nanosheets in 2010 using an air-and-water combination.
"We often think of oil on water as something that is environmentally bad when, in fact, my group over the past 20 years has been studying the unique properties of the junction between water and oil as an interesting place for molecules to assemble in unique ways -- including for soaps and oil dispersants," said Richmond, who holds a UO presidential chair. "This study shows it is also a unique platform for making nanosheets."
Lead authors on the project were Ellen J. Robertson, a doctoral student in Richmond's lab at the time of the research, and Gloria K. Oliver, a postdoctoral researcher at LBNL. Robertson is now a postdoctoral researcher at LBNL.
Work in Richmond's lab helped to identify the mechanism behind the formation of the nanosheets at an oil-water interface.
"Supramolecular assembly at an oil-water interface is an effective way to produce 2D nanomaterials from peptoids because that interface helps pre-organize the peptoid chains to facilitate their self-interaction," said Zuckermann, a senior scientist at LBNL's Molecular Foundry in a news release. "This increased understanding of the peptoid assembly mechanism should enable us to scale-up to produce large quantities, or scale- down, using microfluidics, to screen many different nanosheets for novel functions."
Zuckermann and Richmond are the corresponding authors on the paper. Additional co-authors are Menglu Qian and Caroline Proulx, both of LBNL.
Like natural proteins, synthetic proteins fold and conform into structures that allow them to do specific functions. In his earlier work, Zuckermann's team at LBNL's Molecular Foundry discovered a technique to synthesize peptoids into sheets that were just a few nanometers thick but up to 100 micrometers in length. These were among the largest and thinnest free-floating organic crystals ever made, with an area-to-thickness equivalent of a plastic sheet covering a football field.
"Peptoid nanosheet properties can be tailored with great precision," Zuckermann says, "and since peptoids are less vulnerable to chemical or metabolic breakdown than proteins, they are a highly promising platform for self-assembling bio-inspired nanomaterials."
To create the new version of the nanosheets, the research team used vibrational sum frequency spectroscopy to probe the molecular interactions between the peptoids as they assemble at the oil-water interface. The work showed that peptoid polymers adsorbed to the interface are highly ordered in a way that is influenced by interactions between neighboring molecules.
The substitution of oil in place of air creates a raft of new opportunities for the engineering and production of peptoid nanosheets, the researchers said. The oil phase, for example, could contain chemical reagents, serve to minimize evaporation of the aqueous phase or enable microfluidic production.
The U.S. Department of Energy's Office of Basic Energy Sciences (grant DE-FG02-96ER45557) supported the research done in Richmond's UO lab. Work at the Molecular Foundry at LBNL was supported by the DOE (under contract DE-AC02-05CH11231) and the Defense Threat Reduction Agency (grant IACRO-B1144571).
Media Contact: Jim Barlow, director of science and research communications, 541-346-3481, firstname.lastname@example.org
Sources: Geraldine Richmond is traveling but can be reached through the media contact above; Ronald Zuckermann, Molecular Foundry at Lawrence Berkeley National Laboratory, 510-486-7091, email@example.com
Jim Barlow | Eurek Alert!
27.03.2015 | Oak Ridge National Laboratory
How did the chicken cross the sea?
27.03.2015 | Michigan State University
In an experiment at the Department of Energy's SLAC National Accelerator Laboratory, scientists precisely measured the temperature and structure of aluminum as...
The IPH presents a solution at HANNOVER MESSE 2015 to make ship traffic more reliable while decreasing the maintenance costs at the same time. In cooperation with project partners, the research institute from Hannover, Germany, has developed a sensor system which continuously monitors the condition of the marine gearbox, thus preventing breakdowns. Special feature: the monitoring system works wirelessly and energy-autonomously. The required electrical power is generated where it is needed – directly at the sensor.
As well as cars need to be certified regularly (in Germany by the TÜV – Technical Inspection Association), ships need to be inspected – if the powertrain stops...
When an earthquake hits, the faster first responders can get to an impacted area, the more likely infrastructure--and lives--can be saved.
The Atlantic overturning is one of Earth’s most important heat transport systems, pumping warm water northwards and cold water southwards. Also known as the Gulf Stream system, it is responsible for the mild climate in northwestern Europe.
Scientists now found evidence for a slowdown of the overturning – multiple lines of observation suggest that in recent decades, the current system has been...
Because they are regularly subjected to heavy vehicle traffic, emissions, moisture and salt, above- and underground parking garages, as well as bridges, frequently experience large areas of corrosion. Most inspection systems to date have only been capable of inspecting smaller surface areas.
From April 13 to April 17 at the Hannover Messe (hall 2, exhibit booth C16), engineers from the Fraunhofer Institute for Nondestructive Testing IZFP will be...
25.03.2015 | Event News
19.03.2015 | Event News
17.03.2015 | Event News
27.03.2015 | Agricultural and Forestry Science
27.03.2015 | Materials Sciences
27.03.2015 | Ecology, The Environment and Conservation