Electrochemical biosensors and method of preparing electrochemical biosensors

A method of manufacturing a biosensor, comprising:

• printing electrodes on a substrate using metallic ink;
• printing a carbon surface using carbon-containing ink, the carbon surface being in electrical communication with the electrodes;
• immersing the substrate in an acid bath having a pH of 3.0 or less and applying a first voltage cycle to the biosensor electrodes;
• and
• immersing the substrate in a basic bath having a pH of 13.0 or more and applying a second voltage cycle;
• wherein each of the first voltage cycle and the second voltage cycle comprise a minimum voltage that is less than 0 V and a maximum voltage that is greater than 0 V, the minimum voltage and the maximum voltage being selected to avoid damaging the electrodes and the carbon surface across a plurality of first voltage cycles and a plurality of second voltage cycles.