Abstract: The present invention describes a new electrochemical biosensor comprising (i) a biocatalyst producing a pH change when interacting with the analyte to be determined and (ii) a compound exhibiting different redox properties both in its protonated and non-protonated forms (pH-sensitive redox compound). The elements described above are integrated in a biosensor system composed of a working electrode and a reference electrode connected to an ammeter. When the analyte is present, the system produces a current change that is proportional to the concentration of the analyte. The biosensors described herein can be used in the accurate detection of a wide range of analytes. They can be used in diagnostics, industrial processes, food and feed quality control, biotechnology, pharmaceutical industry, environmental monitoring and so on.

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.