WEST LAFAYETTE, Ind. – Researchers at Purdue University have designed and developed a portable biosensor device that can rapidly detect pathogens in agricultural environments.

“The original motivation for developing a biosensor device for on-farm use was a networking event where I was sitting next to a beef cattle farmer who was mentioning his challenges in managing bovine respiratory disease,” said Mohit Verma, associate professor of agricultural and biological engineering at Purdue. “He mentioned that if he knew which bacteria or virus was causing the disease with a quick on-farm test, his management decisions would be much better.”

In 2020, a team of researchers led by Verma was awarded a $1 million USDA National Institute of Food and Agriculture Inter-Disciplinary Engagement in Animal Systems (IDEAS) grant to develop a technology that could reduce the diagnosis time of bovine respiratory disease to 30 minutes. Since then, the group has published multiple papers demonstrating the technology’s ability to detect bacteria in bovine nasal samples among other applications, such as the detection of COVID-19 in saliva samples and the ability to identify genetically modified corn and soybean.

The latest application of the technology is food safety on produce farms with the ability to detect aerosolized fecal contaminants. Research published by the team in 2024 found that the biosensor technology delivered 100 percent accurate results within an hour of in-field sample collection.

The biosensors are based on a technology known as loop mediated isothermal amplification (LAMP), which can detect DNA or RNA by heating the sample to a temperature of 65 degrees Celsius, Verma said.

“When the heat is provided, the nucleic acids amplify and cause a color change if the target is present. The target could be a pathogen, indicator bacteria, or genes (such as those for antimicrobial resistance or genetically modified traits),” he continued. “The heater device allows the heating process to take place in a simple manner.”

To that end, the goal is for the biosensor devices and assay tests to be operated by farmers or veterinarians with minimal training. The workflow involves collecting a sample, resuspending the sample in water, transferring the sample to the biosensor paper pads and sealing the pads, placing the biosensors in the heating device, and observing the color changes visually or by a camera, Verma explained.

Verma and his group’s new research development is IsoHeat, the device that provides the heat needed for LAMP assays in the field. IsoHeat can reach 65 degrees Celcius in just 12 minutes, whereas a commercially available precision cooker tested against IsoHeat took 36 minutes to reach the same temperature. Verma, alongside doctoral students Nafisa Rafiq and Bibek Raut, recently submitted a patent application for related technologies.

“The device really helps to bring lab-quality results to the farm and provide quicker actionable information. Such capabilities don’t currently exist and most of the time such testing is not done due to slow turnaround,” Verma said.

Verma and his research group are currently working on increasing the user-friendliness of the device and are working with improved versions of the device in the field to provide data in a real-world setting. Additionally, the group is working on integrating automated image analysis to simplify the interpretation of results.

Beyond the lab, Verma serves as the chief technology officer of Krishi, a startup company focused on developing molecular assays that provide actionable insights for agriculture and animal health markets. The company’s website states that there are “hundreds of potential applications” for Krishi’s proprietary platform and it “may replace diagnostics currently conducted only in a laboratory or provide valuable insights through entirely new applications.” The website immediately lists antimicrobial resistance, bovine respiratory disease, African swine fever and crop pathogens as applications.