Use of perfluoropolymers in the determination of the receptor-ligand binding constant

A method for determining the binding constant of interacting molecular species and of the concentration of a ligand in an aqueous solution comprising the step of:

• measuring the intensity of the light reflected from an interface between the aqueous solution and a flat surface comprising at least one perfluoropolymer, at least one receptor that is adsorbed to the surface of the perfluoropolymer or chemically bound to the surface of the perfluoropolymer, and at least one ligand molecule that interacts with the receptor;
• correlating the measured light intensity with a concentration of the ligand;
• and
• obtaining the binding constant based on the correlation,
• wherein the measuring of the intensity of the light comprises:
• contacting the surface of the perfluoropolymer with an aqueous solution containing the receptor to form a first solution;
• adding a predetermined volume of an aqueous solution of a ligand having a predetermined concentration to the first solution to obtain a second solution, wherein the ligand concentration is [T0 ];
• repeating the adding of a predetermined volume of an aqueous solution of the ligand to the second solution and measuring after each adding of the predetermined volume of the aqueous solution of the ligand the light intensity data/reflected from the interface between the aqueous solution of the ligand and the surface of the perfluoropolymer in the second solution;
• and
• measuring light intensity in the absence of the polymer;
• wherein the correlating the measured light intensity with the concentration of the ligand comprises correlating the reflected light intensity data/as a function of the ligand concentration [T0].