Low-cost conductive polypropylene for electroanalysis in organic solvents using additively manufactured electrodes

Additive manufacturing electrochemistry allows for the production of bespoke sensing devices, that can be produced rapidly on-site. Through the production of specialised filament, researchers have been able to begin to compete with the electroanalytical performance of classical electrodes, however, only aqueous systems have ever been viable for exploration. In this work, we report the first production of a low material cost poly(propylene) (PP) based conductive filament and its application toward electroanalysis within an organic medium, acetonitrile. By leveraging the chemical stability of PP, alongside the conductive properties of carbon black (CB) and the low-cost nature of graphite (G), high-performance electrodes could be printed at a material cost of less than £0.01 each. The filament containing 20 wt% CB, 20 wt% G and 60 wt% PP was electrochemically characterised, producing a k⁰ of 2.08 (± 0.22) x 10^–3 cm s^-1. The additive manufactured electrodes were then applied to detect chlorpromazine in acetonitrile, producing a sensitivity of 51.8 nA μM^-1, limit of detection of 80 μM and limit of quantification of 266 μM. This work shows how, through the production of bespoke filaments, additive manufacturing electrochemistry can explore new areas of electrochemical research that are currently untapped.