Scientists at Umeå University have developed a highly sensitive technique for detecting bacterial spores—stubborn microorganisms that can survive extreme conditions and contribute to food poisoning and infections. This advancement could play a key role in improving food safety and healthcare.
Jonas Segervald and Dmitry Malyshev in the lab. Image Credit: Daniel Nilsson
Bacterial spores are among nature’s most resilient life forms. These tiny, seed-like structures allow bacteria to enter a dormant state, enabling them to withstand boiling water, disinfectants, and even radiation—conditions that would typically destroy most bacteria. Their durability and ability to reactivate under favorable conditions pose significant challenges in healthcare, agriculture, and food production.
In this interdisciplinary study, we have developed a new, ultra-sensitive method to detect bacterial spores by combining nanoscience and biophysics.
Jonas Segervald, Doctoral Student, Department of Physics, Umeå University
Segervald is one of the researchers behind the discovery, which was recently published in ACS Sensors.
Early Detection Crucial in Industry
The method relies on gold nanorods and laser technology to amplify signals from a molecule unique to spores. Using surface-enhanced Raman spectroscopy (SERS), researchers can detect incredibly small chemical traces—down to individual molecules. This makes it possible to identify bacterial spores at extremely low concentrations, allowing for early intervention in industries where contamination is a serious concern.
Spores are highly problematic in hospitals and the food industry, as they can cause recurring contamination by attaching to surfaces and equipment, leading to illness, spoilage and costly cleaning measures.
Dmitry Malyshev, Staff Scientist, Department of Physics, Umeå University
Health Risks in Dairy Production
One area where this method could be especially useful is dairy production. Bacterial spores, particularly from Bacillus species, pose a significant threat to milk and dairy products, potentially leading to spoilage, product recalls, and health risks. Given that dairy is a staple in Sweden’s diet, ensuring high food safety standards is a priority.
The research team successfully detected spores in a contaminated milk sample, highlighting the method’s real-world potential.
Segervald concluded, “Our method offers enhanced sensitivity, allowing us to detect much smaller amounts of bacterial spores than previously possible. Although we are still in the early stages, we are actively working to improve this technology into a practical sensor that can be customized for industries at risk of spore contamination.”
Journal Reference:
Segervald, J. et. al. (2025) Ultra-Sensitive Detection of Bacterial Spores via SERS. ASC Sensors. doi.org/10.1021/acssensors.4c03151