High-tech tactic may expose stealthy salmonella

Apr 10, 2012 By Marsha Wood
Transmission electron microscope image of biopolymer spheres coated (encapsulated) with silver nanoparticles, which might make an ideal surface (substrate) for SERS detection of foodborne pathogens in food and beverage samples. Credit: Jaya Sundaram

Even the smallest quantity of Salmonella may, in the future, be easily detected with a technology known as SERS, short for "surface-enhanced Raman scattering." U.S. Department of Agriculture (USDA) scientist Bosoon Park at Athens, Ga., is leading exploratory studies of this analytical technique's potential for quick, easy and reliable detection of Salmonella and other foodborne pathogens.

According to the U.S. , Salmonella causes more than one million cases of illness in the United States every year.

If SERS proves successful for cornering Salmonella, the technique might be used at public health laboratories around the nation to rapidly identify this or other pathogens responsible for outbreaks of foodborne illness, according to Park, an agricultural engineer with USDA's Agricultural Research Service (ARS). What's more, tomorrow's foodmakers might use SERS at their in-house quality control labs.

ARS is USDA's chief intramural scientific research agency. Park's research supports the USDA priority of enhancing food safety.

In a SERS analysis, a specimen is placed on a surface, such as a stainless steel plate, that has been "enhanced" or changed from smooth to rough. For some of their research, Park's team enhanced the surface of stainless steel plates by coating them with , made up of a biopolymer encapsulated with nanoparticles of silver.

, and colloidal metals such as silver, can enhance the scattering of light that occurs when a specimen, placed on this "nanosubstrate," is scanned with the Raman spectrometer's laser beam.

The that comes back to the forms a distinct spectral pattern known as a Raman spectral signature, or Raman scattered signal. Researchers expect to prove the concept that all molecules, such as those that make up Salmonella, have their own unique Raman spectral signature.

The idea of using a substrate of for Raman spectroscopy is not new. But in SERS studies to detect foodborne pathogens, the use of a surfac—enhanced with biopolymers coated with silver nanoparticles—is apparently novel.

In work with comparatively large concentrations of two different kinds, or serotypes, of enterica—Enteritidis and Typhimurium—Park's tests showed, apparently for the first time, that SERS can differentiate these two serotypes. With further research, SERS may prove superior for finding very small quantities of bacteria in a complex, real-world background, such as a food or beverage sample, Park notes.

He collaborated in the research with Arthur Hinton, Jr., Kurt C. Lawrence, Jaya Sundaram, William R. Windham, and Seung Chul Yoon, all with ARS at the agency's Richard B. Russell Research Center in Athens; Yao-Wen Huang and Yiping Zhao of the University of Georgia-Athens; Yongkuk Kwon of South Korea's Animal, Plant, and Fisheries Quarantine and Inspection Agency; and others.

Explore further: How to reset a diseased cell

More information: Read more about the research in the April 2012 issue of Agricultural Research magazine.

Related Stories

Biosensors: Sweet and simple

Apr 14, 2011

Surface-enhanced Raman spectroscopy (SERS) is a highly sensitive and versatile analytical tool that is widely used in biosensing applications. In conventional Raman spectroscopy, molecules are detected by ...

ORNL nanoprobe creates world of new possibilities

Jul 15, 2004

A technology with proven environmental, forensics and medical applications has received a shot in the arm because of an invention by researchers at the Department of Energy's Oak Ridge National Laboratory. ORNL's nanoprobe, which ...

Securing the nation with fingerprinting materials

Nov 09, 2010

Lawrence Livermore National Laboratory researchers may have found a way to improve Raman spectroscopy as a tool for identifying substances in extremely low concentrations. Potential applications for Raman ...

Recommended for you

How to reset a diseased cell

May 01, 2015

In proof-of-concept experiments, researchers at University of California, San Diego School of Medicine demonstrate the ability to tune medically relevant cell behaviors by manipulating a key hub in cell communication networks. ...

Mechanisms for continually producing sperm

May 01, 2015

Continually producing sperm over a long time is important to procreate the next generation. Researchers of the National Institute for Basic Biology, National Institutes of Natural Sciences in Japan, Ms. Kanako ...

Training pig skin cells for neural development

May 01, 2015

A pig's skin cells may hold the key to new treatments and cures for devastating human neurological diseases. Researchers from the University of Georgia's Regenerative Bioscience Center have discovered a process ...

Viruses: You've heard the bad—here's the good

Apr 30, 2015

"The word, virus, connotes morbidity and mortality, but that bad reputation is not universally deserved," said Marilyn Roossinck, PhD, Professor of Plant Pathology and Environmental Microbiology and Biology at the Pennsylvania ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.