Development of a 3D‐Printed Electrochemical Platform With Dual Working Electrodes for Mesalamine Detection

Additive manufacturing offers a versatile and cost‐effective route for developing electrochemical sensors with customizable designs. In this work, we report an entirely 3D‐printed multiplexed electrochemical device, fabricated via fused deposition modeling using carbon black/polylactic acid filament for the electrodes manufacturing, designed for the determination of mesalamine (MES). The proposed electrochemical platform integrates two working electrodes (E1 and E2), enabling multiplexed detection. After mechanical polishing and chemical/electrochemical activation in 0.5 mol L − 1 NaOH, the electrodes displayed improved surface homogeneity and exposure of conductive domains, as confirmed by scanning electron microscopy, energy dispersive X‐ray spectroscopy, contact angle, and attenuated total reflectance fourier‐transform infrared spectroscopy analyses. The electrochemical behavior was evaluated by cyclic voltammetry, and MES quantification was performed using differential pulse voltammetry. The device exhibited linear response in the 1.0–100 µmol L − 1 range, with limits of detection of 0.42 µmol L − 1 (E1) and 0.37 µmol L − 1 (E2). Recovery studies yielded satisfactory values, ranging from 89 to 113% in synthetic urine and 72 to 116% in human serum, confirming its suitability for complex biological matrices. The combination of low detection limits, reproducibility, and high recovery demonstrates the potential of this low‐cost multiplexed 3D‐printed platform for pharmaceutical monitoring and clinical applications.