Abstract: A system for measuring sulphite in food samples is provided using a biosensor, a method for determining sulphite in food samples using the biosensor, and the biosensor for measuring the sulphite values in food samples. The system uses an amperometric biosensor having a bi-enzymatic system, a working electrode, a counter electrode and a reference electrode. The bi-enzymatic system has the human sulphite oxidase and peroxidase enzymes, and the immobilisation of the enzymes in the working electrode is carried out via simple physical retention. The mixture of the enzymes is mixed with a chemical mediator by applying a sample to the amperometric biosensor; changing the electrical current upon coming into contact with the analyte to be detected; and amperometrically measuring said electrical current in solutions with continuous agitation, using a constant potential.