Magnetic Techniques for Rapid Detection of Pathogens

In situations of widespread infectious disease an action that might result, the rapid diagnosis of pathogenic states will assist first responders in implementing prompt treatments, in a huge reduction in the number of illnesses and deaths. Currently available detection/diagnostic procedures are either time-consuming (8–48 h) and require enrichment and culturing of bacteria before testing, or provide only qualitative results. Magnetic immunoassay technology appears to have particularly superior performance over other immunodetection methods. A typical magnetic immunoassay entails a capture part and a detection part, between which the target is immobilized. The capture part of the immunoassay consists of magnetic particles functionalized to capture the target from the sample. The immobilized target is then sandwiched between the capture and detection complexes and subjected to a detection process that will provide accurate and rapid results, most of the time in a matter of minutes. Another important advantage that a sensitive magnetic immunoassay confers is the reduced volume of samples and reagents needed. This chapter discusses the elements associated with a magnetic immunoassay specifically designed for the rapid detection of pathogens. The chapter presents a review of the different techniques used in the synthesis and encapsulation of magnetic particles, as well as strategies for the immobilization and detection of the targeted pathogen. Several magnetic separation strategies are also discussed.