Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Sandia, UNM researchers mimic photosynthetic proteins to manipulate platinum at the nanoscale


Method has potential of changing the metal’s properties; many new applications possible

Researchers from the Department of Energy’s Sandia National Laboratories and the University of New Mexico have developed a new way of mimicking photosynthetic proteins to manipulate platinum at the nanoscale. The method has the potential of changing the metal’s properties and benefiting emerging technologies.

"While we are in the early stages of research, we see the possibility of manipulating the nanoscale structure of platinum so that we can have control over the size, porosity, composition, surface species, solubility, stability, and other functional properties of these metal nanostructures," says John Shelnutt, the Sandia scientist leading the research effort. "Such control means that the redesigned platinum could be used in many new applications, including catalysis, sensors, and optoelectronic and magnetic devices."

He adds that while research groups have reported a few platinum nanostructures - including nanoparticles, nanowires, nanosheets, and others - the addition of new types of nanostructures is "highly desirable and potentially technologically important."

Working with Shelnutt in the research are Frank van Swol from Sandia, UNM graduate student Yujiang Song, and Eulalia Pereira from the University of Porto in Portugal.

The new method of manipulating platinum was detailed in a paper in the Journal of American Chemical Society published in late December.

The idea for the technique is similar to photosynthesis, in which plants use the energy from sunlight to produce sugar. But instead of manufacturing sugar, the new method changes a platinum ion to the neutral metal atoms. The photosynthetic protein mimicks this repeatedly, allowing metal to be deposited as desired at the nanoscale.

The method involves putting porphyrins - the active part of photosynthetic proteins - along with the platinum salt in an aqueous solution of ascorbic acid at room temperature. The porphyrins are placed in specific locations in the solution where it is intended that metal should be deposited. For example, the porphyrins may be confined to micelles or liposomes. Micelles are spherical assemblies of detergent molecules in which the heads are exposed to the water and the tails stick together in the interior. Liposomes are similar structures but they are larger and have water on the inside and outside separated by a closed membrane - sort of like a cell. The membrane is composed of two layers of detergent molecules, with the heads on the inner and outer surface facing the water and the tails forming the interior of the membrane.

When light is shined on the porphyrins located in these detergent structures, the porphyrins excite, becoming catalysts for platinum reduction and deposition. As this occurs, the metal grows onto the surfaces of the surfactant structures as a thin sheet or in other ways. In the case of micelles, the platinum grows into balls that look like the common toy "Koosh(tm)" ball. The ball size can be controlled by the amount of porphyrins and platinum in the solution, the amount of light illuminating the solution, and the amount of time the light is on.

For the metals platinum and palladium that form these nanostructures, it is enough for the porphyrin molecule to grow only a small metal "seed" particle composed of about 500 atoms. When it reaches this size, the seed starts to catalyze its own rapid growth (by oxidation of ascorbic acid), budding off arms in all directions and creating the Koosh-ball-like nanostructures. The porphyrin provides a convenient method of making these seeds at the location and time desired, leading to a uniform and selectable nanostructure size.

The platinum nanostructures take on a different form when they are prepared under different conditions. When the porphyrin is in a micelle, the platinum nanostructures produced look like Koosh balls. When the porphyrin is in the bilayer membrane of a liposome, the platinum grows in 2-nanometer thick sheet or platinum lace on the outer surface of the membrane, giving circular sheets - sort of like two-dimensional Koosh balls.

Under solution conditions for which the liposomes aggregate, growth can occur along the interfaces of the liposomes to give platinum foamlike materials and foam nanoballs. The type of nanostructure is mainly determined by the type of surfactant assembly upon which the platinum grows and the extent of growth from the individual seed nanoparticles.

Since the porphyrin remains attached to the platinum nanostructure and active in the presence of light, it can also perform other functions besides growing itself. For example when illuminated with light, the platinum nanostructure evolves hydrogen from water. This reaction is similar to one of interest to car manufacturers looking to new ways to build automobiles powered by hydrogen fuel cells.

Shelnutt says that in addition to structuring the platinum, the process also happens very fast. A few minutes in light will create many seeds, which then grow into the mature nanostructures in tens of minutes. And the process is easy to do.

"It’s so simple it’s amazing," Shelnutt says.

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin company, for the U.S. Department of Energy’s National Nuclear Security Administration. With main facilities in Albuquerque, N.M., and Livermore, Calif., Sandia has major R&D responsibilities in national security, energy and environmental technologies, and economic competitiveness.

Sandia media contact: Chris Burroughs,, (505) 844-0948

Sandia Technical Contact: John Shelnutt,, (505) 272-7160

Sandia National Laboratories
A Department of Energy National Laboratory
Managed and Operated by Sandia Corporation
ALBUQUERQUE, NM 87185-0165

Chris Burroughs | Sandia
Further information:

More articles from Life Sciences:

nachricht Dissolving protein traffic jam at the entrance of mitochondria
23.05.2019 | Albert-Ludwigs-Universität Freiburg im Breisgau

nachricht Producing tissue and organs through lithography
23.05.2019 | Goethe-Universität Frankfurt am Main

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: The geometry of an electron determined for the first time

Physicists at the University of Basel are able to show for the first time how a single electron looks in an artificial atom. A newly developed method enables them to show the probability of an electron being present in a space. This allows improved control of electron spins, which could serve as the smallest information unit in a future quantum computer. The experiments were published in Physical Review Letters and the related theory in Physical Review B.

The spin of an electron is a promising candidate for use as the smallest information unit (qubit) of a quantum computer. Controlling and switching this spin or...

Im Focus: Self-repairing batteries

UTokyo engineers develop a way to create high-capacity long-life batteries

Engineers at the University of Tokyo continually pioneer new ways to improve battery technology. Professor Atsuo Yamada and his team recently developed a...

Im Focus: Quantum Cloud Computing with Self-Check

With a quantum coprocessor in the cloud, physicists from Innsbruck, Austria, open the door to the simulation of previously unsolvable problems in chemistry, materials research or high-energy physics. The research groups led by Rainer Blatt and Peter Zoller report in the journal Nature how they simulated particle physics phenomena on 20 quantum bits and how the quantum simulator self-verified the result for the first time.

Many scientists are currently working on investigating how quantum advantage can be exploited on hardware already available today. Three years ago, physicists...

Im Focus: Accelerating quantum technologies with materials processing at the atomic scale

'Quantum technologies' utilise the unique phenomena of quantum superposition and entanglement to encode and process information, with potentially profound benefits to a wide range of information technologies from communications to sensing and computing.

However a major challenge in developing these technologies is that the quantum phenomena are very fragile, and only a handful of physical systems have been...

Im Focus: A step towards probabilistic computing

Working group led by physicist Professor Ulrich Nowak at the University of Konstanz, in collaboration with a team of physicists from Johannes Gutenberg University Mainz, demonstrates how skyrmions can be used for the computer concepts of the future

When it comes to performing a calculation destined to arrive at an exact result, humans are hopelessly inferior to the computer. In other areas, humans are...

All Focus news of the innovation-report >>>



Industry & Economy
Event News

SEMANTiCS 2019 brings together industry leaders and data scientists in Karlsruhe

29.04.2019 | Event News

Revered mathematicians and computer scientists converge with 200 young researchers in Heidelberg!

17.04.2019 | Event News

First dust conference in the Central Asian part of the earth’s dust belt

15.04.2019 | Event News

Latest News

Plumbene, graphene's latest cousin, realized on the 'nano water cube'

23.05.2019 | Materials Sciences

New flatland material: Physicists obtain quasi-2D gold

23.05.2019 | Materials Sciences

New Boost for ToCoTronics

23.05.2019 | Physics and Astronomy

Science & Research
Overview of more VideoLinks >>>