Magnetostrictive particle (MSP) provides sensitive tests for measuring tiny amount of mass and it can serve as a useful device for cell detection and offers potentially effective approaches to clinical diagnosis for detecting bacterial pathogens and early-stage cancer cells. Compared to conventional cells identification methods, MSP biosensor has the advantages of short response time and low cost. It does not require any incubation process thus provides a reagent free direct measurement in practice which does not require any complicated biochemical reactions. Each MSP sensor contains magnetostrictive materials coated with modified antibodies and such structure makes the sensor generate different resonance frequencies in an induced magnetic field after exposure to different concentrations of cells.

Those frequency shifts can be analyzed to determine the presence and concentration of certain bacteria or target human cells in body fluid samples. Here we provide a method to use MSPs to detect two type of cells in body fluids. Staphylococcus aureus is used as an example of common infectious pathogens to human and a breast cancer cell line MDA-MB-231 is used as a example for cancer cells. It is found that the detection limit of MSP sensors for cells can be less than 100 CFU/ml. The results are obtained within a few minutes which makes MSP sensors promising tools in diagnosis of bacterial infections and providing early-stage detection of cancer.