New screen-printable graphite-epoxy composites are developed. Different formulations of this electrochemical sensing material were prepared in order to construct amperometric transducers by thick-film technology. Resulting devices were characterized electrochemically using cyclic voltammetry and an optimal graphite content was also determined. The applicability of the optimized transducer material has been evaluated through electrochemical detection of hydrogen peroxide and by the development of a glucose biosensor. In this case, the screen-printable composite is bulk-modified with the addition of glucose oxidase (GOD). The detection of hydrogen peroxide at 1150 mV (Ag/AgCl) serves as the analytical signal. The sensor shows a linear response range for glucose between 0.05 and 2.5 mM in a pH 7.0 buffered solution with 0.1 M phosphate and 0.1 M KCl. Other biosensing systems can be transferred to thick-film technology based on the use of analogous materials (biocomposites) previously studied in our group, i.e. acetylcholinesterase, peroxidase, alcohol oxidase, etc. © 1997 Elsevier Science S.A.