About the affinity interaction of biosensor and precision of the dynamical frequency response measurement

The paper deals with the formation of immunocomplex ASC at the surface of the AT-cut quartz resonator vibrating in thickness-shear mode. The biochemical affinity process can be characterized by association k_a and dissociation k_d kinetic rate constants, the binding between a covalently immobilized small molecule and its relative antibodies. The bindings curves of series resonance frequency f_s vs. time t were measured and discussed. The following problems are considered: activation by cystamine, glutaraldehyde, and albumine as bioactive buffer, ASC antibody solution with phosphate buffer, and regeneration of the biosensor. The precise measuring technique using Agilent E5100A network analyzer was used for this experiment. The possibility of identification of micro-balanced state in liquids is the second interesting case.