Silica-Coated Magnetostrictive Biosensors for Real-Time Detection of Campylobacter Jejuni in Washing Water

It is known that foodborne pathogens have been found to cause food contamination at every stage of food production, processing, and distribution. Campylobacter jejuni (C. jejuni) is one of the most common genera of foodborne pathogens. There is a critical need for developing a simple and affordable device that allows the poultry industry to monitor the dynamic population changes of C. jejuni rapidly and frequently. In this work, biosensors using magnetostrictive particle (MSP) are developed to detect C. jejuni in washing water directly got from chicken factory/company. The MSPs in different sizes are fabricated and coated with three layers of silica. The coatings are highly stable according to the resonance frequency response in pure water and poultry rinse water. Anti-C. jejuni antibodies are well immobilized on silica-coated sensors by covalent bonding to form a biosensor and the immobilization efficiency was tested by ELISA. SEM images and resonance frequencies show that the MSP based biosensors can capture C. jejuni in washing water. The responses of the biosensor in C. jejuni suspension with different concentrations were studied, which were used to determine the detection limit of the biosensor. The detection limits of silica-coated MSP biosensor in bacterial detection is around 10² CFU/mL. However, the silica coated MSP biosensors may have better performance in more complex food systems due to its strong covalent binding antibody attachment. The silica coated MSP biosensors have higher potential application in the food industry for onsite monitoring of microbial populations.