Researchers print, tune graphene sensors to monitor food freshness,
safety

Date:
June 29, 2020
Source:
Iowa State University
Summary:
Researchers are using high-resolution printing technology and
the unique properties of graphene to make low-cost biosensors to
monitor food safety and livestock health.



FULL STORY ========================================================================== 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.

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 National Science Foundation, the U.S. Department of Agriculture,
the Air Force Research Laboratory and the National Institute of Standards
and Technology have supported the project.



==========================================================================
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 (see sidebar) 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."

========================================================================== Story Source: Materials provided by Iowa_State_University. Note: Content
may be edited for style and length.


========================================================================== Journal References:
1. Kshama Parate, Ci'cero C Pola, Sonal V Rangnekar, Deyny L
Mendivelso-
Perez, Emily A Smith, Mark C Hersam, Carmen L Gomes, Jonathan
C Claussen.

Aerosol-jet-printed graphene electrochemical histamine sensors
for food safety monitoring. 2D Materials, 2020; 7 (3): 034002 DOI:
10.1088/2053- 1583/ab8919
2. 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, Jonathan
C. Claussen. Aerosol-Jet-Printed Graphene Immunosensor for
Label-Free Cytokine Monitoring in Serum. ACS Applied Materials &
Interfaces, 2020; 12 (7): 8592 DOI: 10.1021/acsami.9b22183 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2020/06/200629090007.htm

--- up 22 weeks, 6 days, 2 hours, 38 minutes
* Origin: -=> Castle Rock BBS <=- Now Husky HPT Powered! (1337:3/111)