the present invention relates to a novel process for the immobilization of the enzyme on biocompatible gold nanoparticle encapsulated free - standing membranes . the binding of the enzyme occurs through the amine groups and cysteine residues to the gold nanoparticles . the free - standing gold nanoparticle membrane was synthesized at the interface between chloroform containing bisethyl ) ether and aqueous chloroauric acid solution . the membrane is formed spontaneously by the reduction of aucl 4 − ions by daee , this process leading to the formation of gold nanoparticles . the concomitant process of oxidation of daee leads to the creation of a polymeric matrix in which the gold nanoparticles are embedded . the gold nanoparticle membrane is extremely stable , robust , easily handled , malleable and can be grown over large areas and thickness by suitably varying the experimental conditions .