EMATS FOR IMMUNOSENSORS

Electromagnetic acoustic transducers (EMATs) have two inherent advantages. First, they allow the wireless‐electrodeless measurements. Second, they show higher efficiency for exciting and detecting bulk shear waves. These two characteristics are essential for achieving a high‐sensitive oscillator biosensor. This paper shows a Lorentz‐force‐EMAT biosensor with 50‐μm thick aluminum foil for detecting human immunoglobulin G (IgG) by Staphylococcus‐aureus protein A immobilized on both surfaces of the foil oscillator. The fundamental resonance frequency near 32 MHz was monitored during the binding reaction, which successfully detected the frequency change for the IgG solution with a concentration of 1 ng/mL.