Tag Archives: Shaowei Ding

3D-printed graphene sensors for highly sensitive food freshness detection

I love the opening line (lede). From a June 29, 2020 news item on Nanowerk,

Researchers dipped their new, printed sensors into tuna broth and watched the readings.
It turned out the sensors – printed with high-resolution aerosol jet printers on a flexible polymer film and tuned to test for histamine, an allergen and indicator of spoiled fish and meat – can detect histamine down to 3.41 parts per million.
The U.S. Food and Drug Administration has set histamine guidelines of 50 parts per million in fish, making the sensors more than sensitive enough to track food freshness and safety.
…

I find using 3D-printing techniques to produce graphene, a 2-d material, intriguing. Apparently, the technique is cheaper and offers an advantage as it allows for greater precision than other techniques (inkjet printing, chemical vapour depostion [CVD], etc.)

Here’s more detail from a June 25, 2020 Iowa State University news release (also on EurekAlert but published June 29, 2020), which originated the news item,

Making the sensor technology possible is graphene, a supermaterial that’s a carbon honeycomb just an atom thick and known for its strength, electrical conductivity, flexibility and biocompatibility. Making graphene practical on a disposable food-safety sensor is a low-cost, aerosol-jet-printing technology that’s precise enough to create the high-resolution electrodes necessary for electrochemical sensors to detect small molecules such as histamine.
“This fine resolution is important,” said Jonathan Claussen, an associate professor of mechanical engineering at Iowa State University and one of the leaders of the research project. “The closer we can print these electrode fingers, in general, the higher the sensitivity of these biosensors.”
Claussen and the other project leaders – Carmen Gomes, an associate professor of mechanical engineering at Iowa State; and Mark Hersam, the Walter P. Murphy Professor of Materials Science and Engineering at Northwestern University in Evanston, Illinois – have recently reported their sensor discovery in a paper published online by the journal 2D Materials. (…)
…
The paper describes how graphene electrodes were aerosol jet printed on a flexible polymer and then converted to histamine sensors by chemically binding histamine antibodies to the graphene. The antibodies specifically bind histamine molecules.
The histamine blocks electron transfer and increases electrical resistance, Gomes said. That change in resistance can be measured and recorded by the sensor.
“This histamine sensor is not only for fish,” Gomes said. “Bacteria in food produce histamine. So it can be a good indicator of the shelf life of food.”
The researchers believe the concept will work to detect other kinds of molecules, too.
“Beyond the histamine case study presented here, the (aerosol jet printing) and functionalization process can likely be generalized to a diverse range of sensing applications including environmental toxin detection, foodborne pathogen detection, wearable health monitoring, and health diagnostics,” they wrote in their research paper.
For example, by switching the antibodies bonded to the printed sensors, they could detect salmonella bacteria, or cancers or animal diseases such as avian influenza, the researchers wrote.
Claussen, Hersam and other collaborators (…) have demonstrated broader application of the technology by modifying the aerosol-jet-printed sensors to detect cytokines, or markers of inflammation. The sensors, as reported in a recent paper published by ACS Applied Materials & Interfaces, can monitor immune system function in cattle and detect deadly and contagious paratuberculosis at early stages.
Claussen, who has been working with printed graphene for years, said the sensors have another characteristic that makes them very useful: They don’t cost a lot of money and can be scaled up for mass production.
“Any food sensor has to be really cheap,” Gomes said. “You have to test a lot of food samples and you can’t add a lot of cost.”
Claussen and Gomes know something about the food industry and how it tests for food safety. Claussen is chief scientific officer and Gomes is chief research officer for NanoSpy Inc., a startup company based in the Iowa State University Research Park that sells biosensors to food processing companies.
They said the company is in the process of licensing this new histamine and cytokine sensor technology.
It, after all, is what they’re looking for in a commercial sensor. “This,” Claussen said, “is a cheap, scalable, biosensor platform.”

Here’s a link to and a citation for the two papers mentioned in the news release,

Aerosol-jet-printed graphene electrochemical histamine sensors for food safety monitoring by Kshama Parate, Cícero C Pola, Sonal V Rangnekar, Deyny L Mendivelso-Perez, Emily A Smith, Mark C Hersam, Carmen L Gomes and Jonathan C Claussen. 2D Materials, Volume 7, Number 3 DOI https://doi.org/10.1088/2053-1583/ab8919 Published 10 June 2020 • © 2020 IOP Publishing Ltd

Aerosol-Jet-Printed Graphene Immunosensor for Label-Free Cytokine Monitoring in Serum by Kshama Parate, Sonal V. Rangnekar, Dapeng Jing, Deyny L. Mendivelso-Perez, Shaowei Ding, Ethan B. Secor, Emily A. Smith, Jesse M. Hostetter, Mark C. Hersam, and Jonathan C. Claussen. ACS Appl. Mater. Interfaces 2020, 12, 7, 8592–8603 DOI: https://doi.org/10.1021/acsami.9b22183 Publication Date: February 10, 2020 Copyright © 2020 American Chemical Society

Both papers are behind paywalls.

You can find the NanoSpy website here.

Better way to stimulate nerve growth with graphene and electricity

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For all the talk about research with stem cells, it seems they’re not that easy to produce. An April 10, 2017 news item on ScienceDaily describes the problem and how a research team at Iowa State University may have developed a solution,

Researchers looking for ways to regenerate nerves can have a hard time obtaining key tools of their trade.

Schwann cells are an example. They form sheaths around axons, the tail-like parts of nerve cells that carry electrical impulses. They promote regeneration of those axons. And they secrete substances that promote the health of nerve cells.

In other words, they’re very useful to researchers hoping to regenerate nerve cells, specifically peripheral nerve cells, those cells outside the brain and spinal cord.

But Schwann cells are hard to come by in useful numbers.

So researchers have been taking readily available and noncontroversial mesenchymal stem cells (also called bone marrow stromal stem cells that can form bone, cartilage and fat cells) and using a chemical process to turn them, or as researchers say, differentiate them into Schwann cells. But it’s an arduous, step-by-step and expensive process.

Researchers at Iowa State University are exploring what they hope will be a better way to transform those stem cells into Schwann-like cells. They’ve developed a nanotechnology that uses inkjet printers to print multi-layer graphene circuits and also uses lasers to treat and improve the surface structure and conductivity of those circuits.

Iowa State University researchers, left to right, Metin Uz, Suprem Das, Surya Mallapragada and Jonathan Claussen are developing technologies to promote nerve regrowth. The monitor shows mesenchymal stem cells (the white) aligned along graphene circuits (the black). Credit: Photo by Christopher Gannon/Iowa State University

An April 10, 2017 Iowa State University news release, which originated the news item, provides more details about the problems with the current process and the possible solution (Note: Links have been removed),

It turns out mesenchymal stem cells adhere and grow well on the treated circuit’s raised, rough and 3-D nanostructures. Add small doses of electricity – 100 millivolts for 10 minutes per day over 15 days – and the stem cells become Schwann-like cells.

The researchers’ findings are featured on the front cover of the scientific journal Advanced Healthcare Materials. Jonathan Claussen, an Iowa State assistant professor of mechanical engineering and an associate of the U.S. Department of Energy’s Ames Laboratory, is lead author. Suprem Das, a postdoctoral research associate in mechanical engineering and an associate of the Ames Laboratory; and Metin Uz, a postdoctoral research associate in chemical and biological engineering, are first authors.

The project is supported by funds from the Roy J. Carver Charitable Trust, the U.S. Army Medical Research and Materiel Command, Iowa State’s College of Engineering, the department of mechanical engineering and the Carol Vohs Johnson Chair in Chemical and Biological Engineering held by Surya Mallapragada, an Anson Marston Distinguished Professor in Engineering, an associate of the Ames Laboratory and a paper co-author.

“This technology could lead to a better way to differentiate stem cells,” Uz said. “There is huge potential here.”

The electrical stimulation is very effective, differentiating 85 percent of the stem cells into Schwann-like cells compared to 75 percent by the standard chemical process, according to the research paper. The electrically differentiated cells also produced 80 nanograms per milliliter of nerve growth factor compared to 55 nanograms per milliliter for the chemically treated cells.

The researchers report the results could lead to changes in how nerve injuries are treated inside the body.

“These results help pave the way for in vivo peripheral nerve regeneration where the flexible graphene electrodes could conform to the injury site and provide intimate electrical stimulation for nerve cell regrowth,” the researchers wrote in a summary of their findings.

The paper reports several advantages to using electrical stimulation to differentiate stem cells into Schwann-like cells:

doing away with the arduous steps of chemical processing

reducing costs by eliminating the need for expensive nerve growth factors

potentially increasing control of stem cell differentiation with precise electrical stimulation

and creating a low maintenance, artificial framework for neural damage repairs.

A key to making it all work is a graphene inkjet printing process developed in Claussen’s research lab. The process takes advantages of graphene’s wonder-material properties – it’s a great conductor of electricity and heat, it’s strong, stable and biocompatible – to produce low-cost, flexible and even wearable electronics.

But there was a problem: once graphene electronic circuits were printed, they had to be treated to improve electrical conductivity. That usually meant high temperatures or chemicals. Either could damage flexible printing surfaces including plastic films or paper.

Claussen and his research group solved the problem by developing computer-controlled laser technology that selectively irradiates inkjet-printed graphene oxide. The treatment removes ink binders and reduces graphene oxide to graphene – physically stitching together millions of tiny graphene flakes. The process makes electrical conductivity more than a thousand times better.

The collaboration of Claussen’s group of nanoengineers developing printed graphene technologies and Mallapragada’s group of chemical engineers working on nerve regeneration began with some informal conversations on campus.

That led to experimental attempts to grow stem cells on printed graphene and then to electrical stimulation experiments.

“We knew this would be a really good platform for electrical stimulation,” Das said. “But we didn’t know it would differentiate these cells.”

But now that it has, the researchers say there are new possibilities to think about. The technology, for example, could one day be used to create dissolvable or absorbable nerve regeneration materials that could be surgically placed in a person’s body and wouldn’t require a second surgery to remove.

Here’s a link to and a citation for the paper,

Stem Cell Differentiation: Electrical Differentiation of Mesenchymal Stem Cells into Schwann-Cell-Like Phenotypes Using Inkjet-Printed Graphene Circuits by Suprem R. Das, Metin Uz, Shaowei Ding, Matthew T. Lentner, John A. Hondred, Allison A. Cargill, Donald S. Sakaguchi, Surya Mallapragada, Jonathan C. Claussen. Advanced Healthcare Materials Volume 6, Issue 7
April 5, 2017) DOI: 10.1002/adhm.201770032

I expect this paper is behind a paywall.

Treating graphene with lasers for paper-based electronics

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Engineers at Iowa State University have found a way they hope will make it easier to commercialize graphene. A Sept. 1, 2016 news item on phys.org describes the research,

The researchers in Jonathan Claussen’s lab at Iowa State University (who like to call themselves nanoengineers) have been looking for ways to use graphene and its amazing properties in their sensors and other technologies.

Graphene is a wonder material: The carbon honeycomb is just an atom thick. It’s great at conducting electricity and heat; it’s strong and stable. But researchers have struggled to move beyond tiny lab samples for studying its material properties to larger pieces for real-world applications.

Recent projects that used inkjet printers to print multi-layer graphene circuits and electrodes had the engineers thinking about using it for flexible, wearable and low-cost electronics. For example, “Could we make graphene at scales large enough for glucose sensors?” asked Suprem Das, an Iowa State postdoctoral research associate in mechanical engineering and an associate of the U.S. Department of Energy’s Ames Laboratory.

But there were problems with the existing technology. Once printed, the graphene had to be treated to improve electrical conductivity and device performance. That usually meant high temperatures or chemicals – both could degrade flexible or disposable printing surfaces such as plastic films or even paper.

Das and Claussen came up with the idea of using lasers to treat the graphene. Claussen, an Iowa State assistant professor of mechanical engineering and an Ames Laboratory associate, worked with Gary Cheng, an associate professor at Purdue University’s School of Industrial Engineering, to develop and test the idea.

A Sept. 1, 2016 Iowa State University news release (also on EurekAlert), which originated the news item, provides more detail about the intellectual property, as well as, the technology,

… They found treating inkjet-printed, multi-layer graphene electric circuits and electrodes with a pulsed-laser process improves electrical conductivity without damaging paper, polymers or other fragile printing surfaces.

“This creates a way to commercialize and scale-up the manufacturing of graphene,” Claussen said.

…

Two major grants are supporting the project and related research: a three-year grant from the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 11901762 and a three-year grant from the Roy J. Carver Charitable Trust. Iowa State’s College of Engineering and department of mechanical engineering are also supporting the research.

The Iowa State Research Foundation Inc. has filed for a patent on the technology.

“The breakthrough of this project is transforming the inkjet-printed graphene into a conductive material capable of being used in new applications,” Claussen said.

Those applications could include sensors with biological applications, energy storage systems, electrical conducting components and even paper-based electronics.

To make all that possible, the engineers developed computer-controlled laser technology that selectively irradiates inkjet-printed graphene oxide. The treatment removes ink binders and reduces graphene oxide to graphene – physically stitching together millions of tiny graphene flakes. The process makes electrical conductivity more than a thousand times better.

“The laser works with a rapid pulse of high-energy photons that do not destroy the graphene or the substrate,” Das said. “They heat locally. They bombard locally. They process locally.”

That localized, laser processing also changes the shape and structure of the printed graphene from a flat surface to one with raised, 3-D nanostructures. The engineers say the 3-D structures are like tiny petals rising from the surface. The rough and ridged structure increases the electrochemical reactivity of the graphene, making it useful for chemical and biological sensors.

All of that, according to Claussen’s team of nanoengineers, could move graphene to commercial applications.

“This work paves the way for not only paper-based electronics with graphene circuits,” the researchers wrote in their paper, “it enables the creation of low-cost and disposable graphene-based electrochemical electrodes for myriad applications including sensors, biosensors, fuel cells and (medical) devices.”

Here’s a link to and a citation for the paper,

3D nanostructured inkjet printed graphene via UV-pulsed laser irradiation enables paper-based electronics and electrochemical devices by Suprem R. Das, Qiong Nian, Allison A. Cargill, John A. Hondred, Shaowei Ding, Mojib Saei, Gary J. Cheng, and Jonathan C. Claussen. Nanoscale, 2016,8, 15870-15879 DOI: 10.1039/C6NR04310K First published online 12 Jul 2016

This paper is open access but you do need to have registered for your free account to access the material.

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Tag Archives: Shaowei Ding

3D-printed graphene sensors for highly sensitive food freshness detection

Better way to stimulate nerve growth with graphene and electricity

Treating graphene with lasers for paper-based electronics