Progresses of Magnetic Relaxation Switch Sensor in Medical Diagnosis and Food Safety Analysis

Fast and accurate detection of complex samples in either medical diagnosis or food safety analysis are of great significance for the safeguarding of human health. Magnetic relaxation switches (MRS) technique based on superparamagnetic nanoparticles (SMP) is the combination of nano-biotechnology, nuclear magnetic resonance, chemistry and immunoassay. MRS assay has the characteristics of high sensitivity and specificity, as well as nondestructive and time-saving, and can be used in turbid complex samples. In this paper, with a brief discussion about the detection theory of superparamagnetic nanosensor, the target type, structural characteristics, limit of detection, state of magnetic nanoparticles and the change of T₂ value of MRS were reviewed. The research progresses of magnetic relaxation switch sensor in medical diagnosis of different biomarkers and the analysis of food hazard factor were also summarized. Accordingly, future research targets from three aspects, e.g., preparation and modification of magnetic nanoparticles, the improvement of detection sensitivity and construction of high flux magnetic relaxation switch sensor, were put forward.