The use of screen-printed carbon electrodes (SPCEs) would simplify the use of these electrochemical biosensors, avoid the fouling of electrodes due to their disposable character and highlight the possibility of carrying out decentralized assays [1], [2], [15] and [16]. Moreover, these devices allow using binding matrices containing the electron-transfer mediator to be also screen-printed, which results in electrochemical advantages such as fast response, low back-ground currents, operational and storage stability [17]. Taking into account the low solubility of tetrathiafulvalene (TTF) in water and its low redox potential, it has been reported as an optimum mediator in order to be screen-printed for working in aqueous solutions [18], [19], [20] and [21]. Consequently, the aim of this work has been the development of electrochemical biosensors using TTF modified SPCEs (SPCTTFEs) with cross-linked SOx (SOx–SPCTTFEs) for the detection and quantification of sulfite in white and red wine samples.