Real‐Time Micromotor Probe for Immune Neutrophil Activation State

Abstract Neutrophil activation is a hallmark of the immune response. Approaches to identify neutrophil activation in real time are necessary but are still lacking. In this study, magnetic Spirulina micromotors are used as label‐free probes that exhibit differences in motility under different neutrophil activation states. This is correlated with different secretions into the extracellular environment by activated/non‐activated cells and local environmental viscoelasticity. The micromotor platform can bypass non‐activated immune cells while being stopped by activated cells. Thus, the micromotors can serve as label‐free biomechanical probes of the immune cell state. They can detect the activation state of target immune cells in real time and with single‐cell precision, which provides new ideas for the diagnosis and treatment of diseases while deepening understanding of the biomechanics of activated immune cells.