(a) Resonance frequency vs time of PEMS-A: PBS at t=0–10 min, scFv immobilization at 10–35 min, PBS rinsing at 35–43 min, BSA blocking at 43–57 min, PBS rinsing at 57–65 min, and detection of Her2 at 0.1 mg∕ml in background of 1 mg∕ml BSA at 65–90 min and (b) the resonance spectra at t=0 min, 35 min (after scFv immobilization), 57 min (after BSA blocking), and 90 min (after Her2 detection). Note that throughout the detection period, the shape of the resonance peak and the Q value remained constant.