3D-printed hybrid-carbon-based electrodes for electroanalytical sensing applications

In this work we present miniaturized, fully integrated, 3D-printed, hybrid-carbon-based electrodes fabricated using a Fused Deposition Modeling (FDM) 3D-printer. This work is significant because it is the first time that a hybrid carbon-nanotube/carbon black/polylactic acid (CNT/CB/PLA) filament material has been employed in the fabrication of an electrochemical sensing system. The integrated 3D-printed hybrid-carbon electrode is composed of two parts: a non-conductive acrylonitrile butadiene styrene substrate and a conductive CNT/CB/ PLA three-electrode array (comprising working, counter, and pseudo-reference electrodes). The 3D-printed electrodes were activated in a simple and cost-effective two-step process, a chemical step followed by an electrochemical step, leading to a heterogeneous electron transfer constant of 5.02 x 10(-4) cm s(-1). As a proof of concept, the 3D-printed electrodes were used to detect dopamine with a limit of detection of 1.45 mu M. The simplicity, portability, low cost (0.11 USD per electrode), and rapid fabrication (3.7 min) of these fully integrated, 3D-printed, hybrid-carbon-based electrodes indicate that they can be employed as true point-of-care 3D-printed electrochemical sensing systems. We believe that our work paves the way for the development of new conductive nanocomposite PLA filaments for the fabrication of 3D-printed hybrid electrodes with improved performance.