Derivatization of fluorinated polymers and their potential use for the construction of biosensors

Membranes and powders prepared from fluorinated polymers (e.g. Teflon™, PTFE) were investigated for their potential use as multifunctional supports for proteins, enzymes and sugars. To allow covalent coupling of biomolecules to PTFE, the surface of the material was treated with elementary sodium followed by oxidation with ozone or hydrogen peroxide. Derivatization steps were optimized in order to achieve highest loading and short reaction times. The enzymes alliinase (EC 4.4.1.4) and l-lactic dehydrogenase (EC 1.1.1.27), the lectin concanavalin A, and the sugar mannan were chosen as model substances for immobilization. Highest loading of active alliinase was achieved at 48.5 ng cm−2 for membranes and at 1.8 mg g−1 for powder. Values for intact l-lactic dehydrogenase were determined to be at 0.78 ng cm−2 for membranes and at 46.0 ng g−1 for powder.