A radiation grafting technique for the immobilization of enzymes and the heterogenizing of catalytically active homogeneous metal complexes

A novel radiation grafting techniques is discussed for the immobilization of enzymes and the heterogenizing of catalytically active homogeneous metal complexes. For enzyme immobilization, monomers such as p-nitrostyrene are surface grafted to trunk polymers [polypropylene, polyethylene, poly(vinyl chloride)] using ionizing radiation. The nitro-group is converted into the isothiocyanate derivative to which enzyme, trypsin, is covalently bound. In insolubilized form, trypsin retains proteolytic and esterolytic activity. To heterogenize catalytically active homogeneous metal complexes, monomers containing suitable functional groups (NO2, Cl, Br, NH2, PR2) have been radiation grafted to the above trunk polymers. The resulting heterogeneous catalysts are active for the hydrogenation of olefins. The advantages of radiation grafting for the insolubilization of enzymes and metal complexes are discussed. The present preliminary studies show that the technique is (i) feasible; (ii) amenable to ultraviolet light, γ- and electron beam-irradiation procedures; (iii) applicable to any synthetic or natural trunk polymer; and (iv) potentially the most versatile of all insolubilization procedures. (author)