3D Pen: A low-cost and portable tool for manufacture of 3D-printed sensors

[Display omitted] •First manufacture of 3D-printed electrodes using 3D pen (and usual substrates).•3D pen as a simpler, cheaper and more portable tool than FDM 3D printer.•Similar manufacture reproducibility using both instruments (3D pen and 3D printer).•Practical, low-cost (< US$ 0.10) and robust electrochemical sensors.•Electrochemical characterization and analytical applications are demonstrated. 3D printing has been revolutionizing the development of electrochemical devices. Here, 3D pens are proposed for sensor manufacturing as a simpler instrumentation than 3D printers (Fused deposition modeling) for the first time. To illustrate this approach, sensors containing a single working electrode and three-electrode-integrated were manufactured using a 3D pen, which extruded a conductive composite of carbon black (CB) and polylactic acid (PLA) inside molds created into a copper board. After polishing and an electrochemical activation (EA) in NaOH solution, the 3D-pen-printed sensors showed electrochemical responses comparable to glassy carbon electrode for model analytes. The electrode surface (before and after EA) was characterized by scanning electron microscopy, cyclic voltammetry and electrochemical impedance spectroscopy. The manufacture reproducibility of the 3D-pen-printed electrodes was similar to those fabricated in a 3D printer (RSD