DETERMINATION OF AN ANALYTE IN A LIQUID MEDIUM

摘要

Binding between two members of a recognition pair, e.g. antigen-antibody is determined by utilizing a probe comprising a piezoelectric crystal with electrodes on two opposite faces of the crystal. The crystal carries one or more metal plates which may be the same or different than said electrodes, the metal plates having immobilized thereon a first member of a recognition pair. Binding of a second member of the recognition pair to the first member, or dissociation between the two members and release of the second member from the probe, causes a change of immobilized mass which results in a change to the probe's resonance frequency. Said immobilized members may be immobilized on the surface of said metal plates by means of a linking group, having the following general (I): Z-R1-Q wherein Z represents a sulphur-containing moiety which is capable of chemical association with, attachment to or chemisorption onto said metal, R1 represents a connecting group; Q is a functional group which is capable of forming a covalent bond with a moiety of said first member of the recognition pair. The immobilized member may have or be linked to an isomerizable group which changes its isomerization state as a result of exposure to energy.