Main Processes and Materials for 3D Printed Electrochemical Sensors: Focus on Carbon Composites

Electrochemical sensors can detect the quantity of substances of interest, aiding human activities in various fields such as medicine, environment, engineering, chemistry, biology, and others. The recent advancement of versatile 3D printing techniques has allowed their application in numerous areas, including electrochemical sensors. Given the low cost of printers that use polymer filaments, increasing studies have been published in recent years exploring the addition of conductive materials, generally carbon-based, into their filament for electrochemical applications. This work presents a bibliometric analysis on the subject and reviews studies of this range of materials and processes for their production. Despite the complexity of possibilities, some common objectives necessary for the optimized production of 3D printed sensors stand out. They are- defining suitable reagents and processes to ensure a homogeneous dispersion of composites; optimizing the ideal dosage between materials, ensuring a good balance between conduction and printability; executing appropriate surface treatment; configuring the orientation and appropriate printing parameters; studying and selecting materials with a good detection limit for correct modification for specific applications. It is expected that future works will continue to investigate the various factors that affect the properties of these materials, increasingly optimizing the performance of 3D printed sensors.