3D-printed electrochemical sensors for sustainable electroanalysis: a critical assessment of materials, green strategies, and circular economy perspectives

Additive manufacturing (AM) has emerged as a powerful strategy for the fabrication of electrochemical sensors, enabling low-cost, miniaturized, and customizable devices with reduced material consumption. Among the available techniques, fused deposition modeling (FDM) has gained special attention due to its accessibility, simplicity, and compatibility with thermoplastic and composite materials, making it especially attractive for decentralized and resource-limited electroanalytical applications. Despite these advantages, the environmental implications of AM-based electrochemical devices remain underexplored. Most studies focus primarily on analytical performance, with limited consideration of sustainability aspects such as material selection, recyclability, energy consumption, and end-of-life management. In this context, this review provides a comprehensive and critical overview of FDM in electroanalysis, with emphasis on sustainability and circular economic principles. Recent advances in sustainable materials, including bio-based polymers and biomass-derived conductive additives, are discussed alongside strategies for material reuse and reagentless surface modification. This review also highlights the trade-offs between sustainability and electroanalytical performance, addressing key challenges associated with material design and process optimization. The lack of standardized metrics for assessing the environmental footprint of electrochemical sensors is also identified as a critical gap in the field. Overall, this work aims to provide a critical perspective on the integration of sustainability and AM-based electrochemical sensor development, emphasizing the need to balance environmental responsibility with analytical performance and to guide future research toward more sustainable and circular electroanalytical technologies.