Integrated platform for detecting pathogenic DNA via magnetic tunneling junction-based biosensors

•A portable magnetic biosensing platform for detecting pathogens in food is realized.•The detection method is based on hybridization of DNA extracted from pathogens.•A protocol for hybridization of Listeria, Salmonella and HEV DNA is presented.•Detection of Listeria monocytogenes DNA with the new platform is demonstrated. In recent years, the development of portable platforms for performing fast and point-of-care analyses has drawn considerable attention for their wide variety of applications in life science. In this framework, tools combining magnetoresistive biosensors with magnetic markers have been widely studied in order to detect concentrations of specific molecules, demonstrating high sensitivity and ease of integration with conventional electronics. In this work, first, we develop a protocol for efficient hybridization of natural DNA; then, we show the detection of hybridization events involving natural DNA, namely genomic DNA extracted from the pathogenic bacterium Listeria monocytogenes, via a compact magnetic tunneling junction (MTJ)-based biosensing apparatus. The platform comprises dedicated portable electronic and microfluidic setups, enabling point-of-care biological assays. A sensitivity below the nM range is demonstrated. This work constitutes a step forward towards the development of portable lab-on-chip platforms, for the multiplexed detection of pathogenic health threats in food and food processing environment.