How normalisation factors influence the interpretations of 3D-printed sensors for electroanalysis

The ability to produce electrodes through 3D-printing techniques for use in sensing applications has significant potential. This is mainly due to the mass production of electrodes at any desired geometry. However, comparing different 3D-printed carbon electrodes for electroanalytical performance can be challenging due to the significant variation in each conductive printed material. This study investigates different normalisations that could be applied to compare between different 3D-printed electrodes. We compared 3D-printed carbon black and graphene electrodes for the monitoring of three important biological analytes (dopamine, ascorbic acid and hydrogen peroxide). These 3D printed electrodes have different conductive loads and surface profiles, and therefore we utilised eight different approaches for normalising the current response. There was no perfect normalisation technique and therefore using a combination of approaches to survey the best performing electrode would be a better approach. This study showcases the different possible normalisation methods and highlights the impact these can have on the interpretation of electrodes for electroanalytical measurement. •3D printing provides the ability to make electrodes with a vast array of conductive materials•Comparison is complex due to varied surface geometry and conductive loads between electrodes•Normalisation by eight different approaches showcased varying trends in the behaviour of one electrode to another•No single approach of normalisation can be effective for electroanalytical comparison of 3D printed electrodes