The value of coupling biological molecules such as enzymes to solid materials has long been recognized. Presently protein immobilization onto such surfaces often involves covalent coupling, encapsulation, or non-specific adsorption techniques. Andrew K. Johnson and others of University of Idaho, have demonstrated the feasibility of specifically attaching a haloalkane dehalogenase enzyme to silica-coated or uncoated iron oxide superparamagnetic nanoparticles using affinity peptides. The enzyme was cloned from Xanthobacter autotrophicus strain GJ10 into Escherichia coli to produce fusion proteins containing dehalogenase sequences with C-terminal polypeptide repeats that have specific affinity for either silica or iron oxide. The fusion proteins serve dual functions, allowing for specific inorganic surface binding and for enzymatic activity. They have found that the degree of fusion protein adsorption to nanoparticle surfaces was found to exceed that of enzymes that had not been activated with affinity sequences, particularly for iron-oxide nanoparticles.