Vikas Berry is a K-State assistant professor of chemical engineering who works with graphene, a carbon material only a single atom thick and discovered just five years ago. To functionalize graphene with gold -- thus controlling its electronics properties -- Berry and Kabeer Jasuja, a K-State doctoral student in chemical engineering, embedded gold on graphene.
To do this, the engineers placed the graphene oxide sheets in a gold ion solution that had a growth catalyst. Here, the atomically thick sheets swim and bathe in a pool of chemicals.
"Graphene-derivatives act like swimming molecular carpets when in solution and exhibit fascinating physiochemical behavior," Berry said. "If we change the surface functionality or the concentration, we can control their properties."
They found that rather than distributing itself evenly over graphene, the gold formed islands on the sheets' surfaces. They named these islands snowflake-shaped gold nanostars, or SFGNs.
"So we started exploring how these gold nanostars are formed," Berry said. "We found out that nanostars with no surface functionality are rather challenging to produce by other chemical processes. We can control the size of these nanostars and have characterized the mechanism of nucleation and growth of these nanostructures. It's similar to the mechanism that forms real snowflakes."
Berry said the presence of graphene is critical for the formation of the gold nanostars. "If graphene is absent, the gold would clump together and settle down as big chunks," he said. "But the graphene helps in stabilizing the gold. This makes the nanostars more useful for electronic applications."
In July, Jasuja and Berry published their work in the journal ACS-Nano.
The discovery of these gold "snowflakes" on graphene shows promise for biological devices as well as electronics. Berry is attaching DNA to these gold islands to make DNA sensors. He is joined by Nihar Mohanty, a doctoral student in chemical engineering, and undergraduate researcher Ashvin Nagaraja, a senior in electrical engineering. Nagaraja is a 2004 Manhattan High School graduate.
Berry said graphene-gold based DNA sensors will have enhanced sensitivity. Chemically reducing graphene oxide to obtain graphene requires harsh chemicals that destroy the DNA.
"Now we can use the harsh chemicals on graphene oxide imbedded with gold to obtain graphene with gold islands. Then we can use these gold islands to functionalize DNA."
Berry also is using graphene in conjunction with microwaves. He and Jasuja are "cooking" the graphene sheets as another way to produce particles on the material's surface.
Some of Berry's other graphene research involves using the modified graphene sheets to compartmentalize a coagulating solution, thus stabilizing it. His group has recently used hydrides to reduce graphene oxide to produce reduced graphene oxide in the matter of a few seconds. The graphene produced in this way can remain stable in the solution for several days. Further results will shortly appear in the journal Small.
Discovered only five years ago, graphene has captured the attention of a large number of researchers who are studying its exceptional electrical, mechanical and optical properties, Berry said. His research group is among the few studying the material's interfacial properties and biological applications.
"We're entering a new era," Berry said. "From the zero-dimensional or one-dimensional molecular or polymer solutions, we are now venturing into the two-dimensional graphene solutions, which have fascinating new properties."
Vikas Berry, 785-532-5519, email@example.com
Vikas Berry | Newswise Science News
Further reports about: > 24-Carat > 24-Carat Gold > DNA > Graphene Research > Graphene-derivatives > Magnetic Properties > Ornament > chemical engineering > chemical process > electrical properties > electronics applications > gold nanostars > golden discovery > graphene > graphene sheets > molecular carpets > snowflakes
Linear potentiometer LRW2/3 - Maximum precision with many measuring points
17.05.2017 | WayCon Positionsmesstechnik GmbH
First flat lens for immersion microscope provides alternative to centuries-old technique
17.05.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy