Magnetic particles (MPs) in sizes ranging from nanometres to micrometres have gained much attention of researchers to be used in the development of biosensors. Their high surface area allows the immobilisation of the biorecognition molecules at a high density, limiting the background noise. Importantly, they allow to apply sample enrichment and separation in the solution under a magnetic field which makes them perfect candidates for rapid detection of low numbers of pathogens in complex samples . MPs can be either integrated into a transducer or dispersed in a sample and subsequently get attracted using the magnetic field onto the electrode surface (Rocha-Santos, 2014). developed a dual DNA walker strategy for the detection of STEC O157. A DNA walker is defined as a type of nucleic acid nanomachines able to move along a well-designed track comprised of DNA building blocks. These nanomachines are synthesised to mimic the natural DNA walkers like myosin, dynein or kinesin . Subsequently, the modified PCR amplicons were immobilised to streptavidin-magnetic aggregation. In addition, the DNA interacted with positively charged oxidised TMB. As a result of these interactions, the electron transfer and the cathodic current was significantly lower if the target DNA was present in the sample. The authors obtained an LOD of 2x10 -8 M which suggested that this technique was less sensitive compared to other studies summarised in this review. The sensor fabrication was, however, less complex since there was no need for probe immobilisation.