Custom-Formulated MWCNT Inks for Scalable Fabrication of Flexible Screen-Printed Electrodes.

Screen-printing technology enables mass production of disposable electrochemical sensors on diverse substrates, such as ceramic, paper and polymer films. Two fully custom conductive inks—multi‑walled carbon nanotube (MWCNT) and MWCNT/Prussian Blue (PB)—together with a lab‑made Ag paste was formulated for scalable printing of flexible screen‑printed electrodes (SPEs) on cellulose and acetate substrates. Prior to printing, the inks were first characterized by SEM/XRD/FTIR and then optimized for shear-thinning rheology and high conductivity. The resulting SPEs exhibited diffusion‑controlled behavior and good reproducibility. As a practical demonstration, SPEs printed on office paper detected Bisphenol A in tap water with a a limit of detection (LOD) of 0.084 µM with a sensitivity of 1.3 µA·mM -1 ·cm -2 . In addition, SPEs with PB showed a linear amperometric response to H 2 O 2 with an LOD of 5.3 µM (R 2 of 0.95). These results highlight a low-cost, scalable fabrication strategy for SPEs with applications in environmental monitoring and point-of-care testing, especially in resource-limited settings.