Biosensors construction
SPCTTFEs were homemade built using a DEK 248 printing machine (DEK, Weymouth, UK). These transducers consisted of three screen-printed electrodes deposited onto polyethylene terephthalate films (HiFi Industrial Film, Dardilly, France). The different inks were screen-printed and cured according to the manufacturer's specifications [22]. The working electrode ink was prepared by thoroughly mixing carbon ink with TTF (3% v/w) and immediately screen-printed. Fig. 1 shows an image of the SPCEs configuration used (Working area, 15.90 mm2).