A process for making a biosensor comprising a hollow coil comprising wires coiled in parallel and an electronic circuit component connected to the coil, the process comprising: 1) providing a mandrel on which wires including at least a first wire, a second wire and a third wire are wound in parallel, 2a) immersing the mandrel in a first buffer solution comprising a first bioreceptor, a first monomer and optional additives, 2b) arranging the wires such that the first wire may be used as a working electrode, the second wire may be used as a counter electrode and the third wire may be used as a reference electrode of a three electrode electrochemical cell used in an electropolymerisation process, 3) passing electric current through the first wire to form a first biocompatible coating of a first polymer polymerized from the first monomer comprising the first bioreceptor on the first wire, 4) removing the coil from the mandrel, 5) connecting the wires to their respective points of the electronic circuit component such that the first wire may be used as a working electrode, the second wire may be used as a counter electrode and the third wire may be used as a reference electrode and wherein the electronic circuit component is configured such that it can generate an input signal for a wireless receiver based upon the activity of the bioreceptor and wirelessly send the input signal to the wireless receiver.