The interaction between receptor and ligand is specific and reversible. κf, κr andκa, which represent forward rate constant, reverse rate constant and affinity constant, respectively, can be used to describe the characters of the reaction kinetics. Many studies on three-dimensional binding kinetics have been done when either receptor or ligand is in a dissolved state. Another case is that the binding of receptor to ligand is two-dimentional when both of receptor and ligand locate on the surface of cell memb...