Figure 5.

Summary of different sensing modalities: (a) particle binding events are detected by measuring shifts in the resonance frequency of the optical cavity; (b) binding events are detected by broadening of the resonance peak, reflecting a drop in the quality factor of the cavity due to scattering; and (c) particle binding is sensed by measuring changes in trough separation of a resonance doublet. These doublets are created by scattering caused, for example, by the deposition of a nanoparticle on the resonator surface.