A Multiple Magnetoelastic Sensor System for Detection of Salmonella Typhimurium Using Pulse Method

Magnetoelastic sensors show a resonance frequency decrease once target pathogens are attached to the sensors and thus add a small mass to the sensors. These sensors are fast, sensitive, and have higher mass sensitivity with smaller sized sensors. However, signals from smaller sensors are weaker and have more noise due to manufacturing defects. In this paper, we present a pulse biosensor system that is able to avoid bias magnetic field and allows simultaneous detection using multiple sensors. With multisensors, the effect of a manufacturing defect is decreased and we get the benefit of averaging for more accurate and reliable results. Stability tests show that the variance of frequency detection is less than 122 ppm of its resonance frequency. Real detection of pathogen is demonstrated using Salmonella typhimurium and the results show that multiple magnetoelastic biosensors are able to detect S. typhimurium simultaneously and offer good sensitivity and reliability.