The invention concerns a binding matrix containing a carrier material and a solid phase reactant which is adsorbed to this via anchor groups that is capable of binding to at least one free reaction partner wherein the solid phase reactant forms a dilute and essentially laterally homogeneous binding layer on the surface of the carrier material. In addition a method for the determination of an analyte in a sample solution is claimed in which a solid phase reactant is used which is a component of a binding matrix according to the present invention. In this process the specific binding reaction is preferably determined by optical reflection techniques.