Characteristics of the glucose oxidase at different surfaces

By adsorption or chemical bonding, glucose oxidase (GOD) molecules are immobilized to different surfaces, including bare Pt and Au, alkanethiols self-assembled monolayers, and omega-carboxylic acid thiols self-assembled monolayers. Except Au and reduced Pt surfaces, GOD can be immobilized on all the surfaces tested. The most durable immobilization is achieved by covalent bonding GOD to carboxylic terminated SAM. In most cases the immobilized GOD retains its native enzymatic activity. A chain length dependence of the apparent Michealis constant is found for the GOD adsorbed at carboxylic group terminated SAM and the possible reasons are discussed. (C) 1997 Elsevier Science S.A.