A group of PSU researchers has developed a process that may one day make a night out at your favorite restaurant, a trip to the grocery store or turning on the tap in a developing nation a much safer experience.


Research detectives

Tuhina Banerjee, a chemist in the Department of Chemistry, along with Assistant Professor Santimukul Santra, Professor James McAfee, and six students in the department, combined magnetic resonance imaging (MRI) and fluorescence to create a device that enables scientists to detect the presence of dangerous bacteria in food and water, and to do so in less than an hour.

Their research was published last year in the American Chemistry Society (ACS) journal, Infectious Diseases.

The research has major implications because bacterial contamination of food and water is one of the world’s leading causes of sickness and death.

The culprit is often E. coli, a large group of bacteria that surround us every day. Most are harmless, but some, like E. coli 0157: H7, are very dangerous, as companies like Costco and Chipotle have discovered at great cost.

Santra, who came to PSU as part of its Polymer Chemistry Initiative, said news stories about E. coli contamination of foods in the U.S. inspired the PSU researchers to think about using nanosensors to try to detect common pathogens, first in water.

The nanosensors are made up of iron oxide particles combined with an optical dye and antibodies that latch onto the E. coli cells. The nanosensors clump around the bacteria and this can be detected by MRI, for very small amounts, and fluorescence, for large amounts.


The A team

For their research, Banerjee and Santra, teamed up with Professor James McAfee, a biochemist in the department. Additionally, six students assisted in the research and the senior researchers said their help was crucial.

Research team, L-R: Tyler Shelby, Tuhina Banerjee, Santimukul Santra and Professor James McAfee.

Research team, L-R: Tyler Shelby, Tuhina Banerjee, Santimukul Santra and Professor James McAfee.

Shoukath Sulthana, a graduate student in polymer chemistry, and Tyler Shelby, an undergraduate student in chemistry, who worked on developing the new bacterial contamination detector, said the research experience they’ve had at PSU is invaluable.

“I think it goes back to what makes this place special,” Shelby said. “I don’t know where else you would have the contact time with professors that we do here. I’ve spent countless hours in professors’ labs, talking to them about what they’re working on.”

McAfee said Shelby’s PSU experience will be a big boost as Shelby applies to MD/Ph.D. programs.

“Having done this research and having a paper published in a highly regarded journal is worth a thousand A’s,” McAfee said. “That’s one of the reasons that having students involved in this type of research is so important.”

Banerjee said that since the researchers published their work, they have been getting calls from researchers around the world.

“The next step is to work with engineers to develop a chip that can take the process out of the lab and into the field,” Banerjee said.

In the meantime, the researchers are exploring ways to use the technique they’ve developed for the rapid detection of other pathogens, such as influenza and Zika.