Multi-material integrated 3D-printed electrochemical detection platform for rapid on-site screening of nimesulide in industrial sewage.

The fabrication, mechano-electric, and electrochemical characterisation of a sustainable, multi-material, integrated 3D-printed electrochemical platform (3DPEC) for the rapid on-site screening of nimesulide in both static and flow conditions is demonstrated. The portable two-electrode cell comprises carbon black (CB)-filled polylactic acid (PLA) electrodes sealed within insulating poly(lactic acid) walls, constituting an integrated multi-material system. Joint tensile and electrical tests, as well as tomography analyses, enabled the optimisation of 3DPEC dimensions and printing parameters. A practical and straightforward route for 3DPEC post-processing activation was proposed to enhance the electrochemically active surface area (ESA). Finally, we present the (sensitive determination of nimesulide, an anti-inflammatory drug, in industrial sewage after a 1:10 (v/v) dilution in phosphate buffer solution (PBS). The detection platform demonstrated high competitive performance in electroanalysis, with excellent reproducibility (RSD = 6.8% by CV, 3.4% by DPV), a recovery of 90 ± 5%, a detection limit of 0.19 μM, and selectivity against most studied interferents. The presented approach serves as a proof-of-concept for a customisable, multi-material integrated 3D-printed electrochemical detection platform that prioritises reproducibility, low cost, and applicability in complex environmental matrices, highlighting its practical potential for sustainable wastewater monitoring.