The invention relates to a method for precipitating mono or multiple layers of organophosphoric acids of the general formula I (A) Y--B--OPO.sub.3H.sub.2 (IA) or of organophosphonic acids of the general formula I (B) Y--B--PO.sub.3H.sub.2 (IB) and the salts thereof, wherein B is an alkyl, alkenyl, alkinyl, aryl, aralkyl, hetaryl or hetarylalkyl residue and Y is hydrogen or a functional group from the hydroxy, carboxy, amino, optionally low-alkyl-substituted mono or dialkylamino series, thiol, or a negative acid group from the ester, phosphate, phosphonate, sulfate, sulfonate, maleimide, succinimydyl, epoxy, acrylate series, wherein a biological, biochemical or synthetic indicator element may be coupled to B or Y by addition or substitution reaction, wherein compounds may also be added conferring the substrate surface a resistance to protein adsorption and/or to cell adhesion and in the B chain may optionally be comprised one or more ethylene oxide groups, rather than one or more --CH2-- groups. According to the invention, said precipitation occurs on substrate surfaces of pure or mixed oxides, nitrides or carbides of metals and semiconductors, comprising the use of water-soluble salts of a compound of formula (IA) or (IB) for the treatment of these surfaces, in particular as surfaces of sensor platforms, implants and medical accessory devices. The invention also relates to the use thereof as part of coated sensor platforms, implants and medical accessory devices in addition to new organophosphoric acids and organophosphonic acids themselves.The optionally substituted compounds of formulae (IA) and (IB) wherein the B and Y groups have the above-mentioned designations, i.e. optionally substituted alkyl, alkenyl, alkinyl, aryl, aralkyl, hetaryl or hetaryl, are hereinafter referred to as organophosphoric acids and organophosphonic acids.