Magnetic Nanoparticle Relaxation Biosensor — 2D Phasor View

Antibody-coated Fe₃O₄ nanoparticles are simulated as two live populations — free single particles and biomarker-cross-linked clusters — each rotating its magnetic moment toward a driving AC field with its own Brownian relaxation time. As biomarker concentration rises, more particles are pulled into slower-rotating clusters, the phase lag between field and moment grows, and the out-of-phase susceptibility signal — the actual readout of a real magnetic-relaxation immunoassay — climbs with it. This 2D build lays the mechanism out across three linked panels: a pannable/zoomable chamber view of the particle population, a phasor clock showing the field and moment vectors directly, and a Debye-curve panel that plots exactly where the current χ″ reading sits on the universal relaxation response. Sliders for concentration, drive frequency, nanoparticle core size and solution viscosity let you explore why real assays are engineered around a narrow core-size window where Néel relaxation is frozen and only the biomarker-sensitive Brownian rotation carries the signal.