Kinetic study on the interaction between tannin and bovine serum albumin with a wireless magnetoelastic biosensor

A wireless and low-cost magnetoelastic biosensor is developed for the kinetic study on the interaction of tannin with bovine serum albumin (BSA). The measurement is based on the interaction of tannin with BSA which is coated on the magnetoelastic biosensor, producing an insoluble tannin–BSA complex which binds tightly to the sensor surface resulting in a change in the sensor resonance frequency. A pseudo first-order reaction equation is established and the reaction rate constant is calculated to be 0.119 min−1 based on the response curves. The biosensor demonstrates a linear shift in resonance frequency with tannin concentration ranging from 0.60 to 1.08 mM, with a detection limit of 0.10 mM at a noise level of ∼20 Hz.