Application of magnetoelastic biosensors for detection of foodborne pathogens on fresh produce with emphasis on statistical methods for elimination of detection errors

摘要

This work demonstrated a direct detection of Salmonella on fresh food produce using groups of magnetoelastic biosensors. The magnetoelastic biosensors were coated with E2 phage, which specifically binds with S. typhimurium. The resonance frequency of the biosensor is measured using a pulse excitation system, which allows simultaneous detection of multiple sensors. Multiple measurement and control biosensors were placed on fresh food surfaces that had been spiked with a known amount of Salmonella. Binding with bacteria was allowed to occur for 30 minutes in a humid air environment. The resonance frequencies of the groups of biosensors were then measured to determine the amount of bound bacteria. By using a statistical experimental design and by taking the average of repeated measurements, possible detection errors are decreased. By using multiple sensors at each site of interest, a higher portion of the contaminated surface has contact with biosensors, allowing for more complete information on the food produce surface. Results from SEM pictures of the sensor surface agree with the sensor frequency response results.