Biosensor and its use to indicate the status of a product

A biosensor comprises a unit, comprising a substrate and an enzyme, which when brought into contact with the substrate is adapted to affect the substrate so that its conductivity changes as a function of time and temperature, and an electric circuit. The unit is included as a component in said electric circuit and the electric circuit is activable by applying an electric field and/or a magnetic field over the same to generate a measurable signal which is dependent on the total resistance of the circuit. The invention also relates to the use of a biosensor, a label with such a biosensor and a method of indicating the status of a product with such a biosensor.