The simple and compact architecture of this magnetic susceptometer makes it portable enough to detect biological pathogens in the field during outbreaks, resulting in a faster response. Foodborne illness created a $17.6 billion economic burden in 2018, according to the USDA. Fast detection of a pathogen, such as Salmonella, is crucial to public health. Researchers at the University of Florida have developed a portable magnetic susceptometer that allows on-site measurements and faster response times. The susceptometer measures the rotation of magnetic microdiscs in suspension via simple, optical interrogation. The magnetic discs are functionalized to target specific pathogens, which when bound, affect the rotation of the magnetic microdiscs, enabling identification.
Portable magnetic susceptometer to detect and identify harmful pathogens
This susceptometer can quickly and effectively interrogate biological fluid samples through the rotational dynamics of magnetic microdiscs. The machine includes microfabricated magnetic microdiscs, a coil system creating a rotating magnetic field, and an optical transmission system to monitor the disc motion. The disc motion is influenced by local physical properties of the fluid and by the potential presence of biological agents that adhere to the disc surface. The disc rotational behavior is characterized by the phase-shift occurring while sweeping the magnetic field frequency. When a bacterium or other substance binds to the disc, its rotation is slowed down, increasing the phase-shift. This disc rotational dynamics change affects how the light passes through the magnetic suspension, allowing simple detection of targeted substances. The portability of the apparatus allows this detection process to occur on site.
