Detection of Salmonella Typhimurium on Fresh Food Produce Using Phage-Based Magnetoelastic Biosensors

Salmonella Typhimurium on fresh tomato surface using phage-based magnetoelastic (ME) biosensors. The ME biosensors are composed of a ME resonator platform that is coated with filamentous E2 phage (genetically engineered to bind with Salmonella). Actuated and detected through magnetic field, the ME biosensors are wireless sensors. In this study, tomato surfaces were spiked with a known number of Salmonella cells and then allowed to dry in air. The detection was conducted by directly placing ME biosensors on the spiked surface. Measurements of the resonance frequencies of both control and measurement ME biosensors were made prior to the placement and after 30 minutes of the placement. Shifts in the resonance frequency of the measurement biosensors were observed while control sensors showed negligible change. The specific binding of Salmonella to the biosensors was verified by Scanning Electron Microscopy (SEM). The results indicate that this methodology may provide real-time pathogen detection without traditional sampling process.