Abstract: The present invention concerns new electrochemical biosensors for the determination of analytes concentration in sample solutions or suspensions, based on composite transducers containing an electro-conducting material, in the form of powder or grains, a chemical mediator, optionally a substance capable of sorption of said chemical mediator, and a solid binding maker, which is a compound in solid state at room temperature; said biosensors are prepared by incorporating a biocatalyst into the bulk of said composite transducers or by applying a biocatalytic layer onto their surface.