Detection and characterization of exosomes via a polystyrene-coated silica microresonator

Exosomes are promising biomarkers for early-stage cancer diagnostics. We present a lab-on-chip biosensor capable of detecting and characterizing single exosomes using a 30 µm silica microresonator coated with a tailored polystyrene nanoshell. The shell enhances the microresonator’s sensitivity, enabling not only single-exosome detection but also characterization based on protein content relevant to cancer diagnostics. Simulation results show that the polystyrene coating increases the resonance wavelength shift by 52% in the presence of an exosome, allowing the detection of subtle variations in protein composition.