In this thesis, the possibility of application of titanate nanotubes as a solid substrate for immobilization of catalysts in electrochemical (amperometric) sensors was studied. Titanate nanotubes were surface modified with (3-aminopropyl)trimethoxysilane (APTMS) and the influence of reaction conditions on the structure of siloxane layer formed on the surface of titanate nanotubes was studied. Surface amino-groups of titanate nanotubes modified with APTMS were exploited as a reactive sites for covalent immobilization of the redox enzyme peroxidase and for covalent bonding of N-salicyliden-n-propylamino complex of iron(III) on the surface of titanate nanotubes. Titanatne nanototubes modified with peroxidase or with N-salicyliden-n-propylamino complex of iron(III) were embedded into the conductive graphite composite and its electrocatalytic properties were examined. It was found that after immobilization on the surface of titanate nanotubes, peroxidase retains its catalytic activity and that the molecules of immobilized peroxidase can effectively participate in direct electron transfer between the enzyme redox center and electrode or the conductive matrix in which the nanotubes were embedded. Titanate nanotubes with immobilized peroxidase were successfully employed in the construction of amperometric hydrogen peroxide biosensors of the third generation and in the construction of the bi-enzyme biosensor for glucose detection.