Prussian Blue Embedded Carbon Thermoplastic Electrodes Crafted by Pre-Modification of 3D Printable Filaments

Chemical modification of the electrode surface plays a crucial role in electrochemical sensor development. 3D printing has provided an efficient and accessible approach to manufacturing electrochemical sensors; however, there are limited strategies in how to chemically modify electrode surfaces. Novel filaments that mix conductive materials and chemical modifiers have shown promise but often require specialized equipment and thus are not widely accessible. Therefore, widely used approaches focus on deposition into printed electrodes, but these electrodes lack stability over time. Therefore, a new approach to the generation of chemically modified 3D-printed electrodes is required. We established a strategy for the electrodeposition of Prussian blue (PB) onto the surface of a carbon black/polylactic acid (CB/PLA) filament, which was then used to print an electrode that embedded the PB into the CB/PLA. The PB embedded CB/PLA electrode was more stable and had a wider linear range than electrodeposited PB film CB/PLA electrodes. This unique approach also provides the ability to make chemically modified electrodes with unique surface geometries, and we were able to make a glucose biosensor on a PB embedded square grid surface patterned CB/PLA electrode. This electrode could detect glucose consumption from HepG2 cells. Our approach provides a unique, widely accessible, and impactful approach for chemically modifying conductive printable filaments to make chemically modified electrodes, which can be used to make a range of diverse electrodes for various applications.