Fully Inkjet-Printed Glucose Sensor on Flexible Polyimide Substrate

Continuous and reliable glucose monitoring is essential for effective diabetes management and point-of-care (POC) healthcare applications. In this work, we report a fully inkjet-printed, flexible, non-enzymatic glucose sensor fabricated on a polyimide substrate using a template-free Mn3O4ink deposited on an interdigitated planar electrode architecture. Unlike conventional Mn3O4-based glucose sensors, here the sensing response is governed primarily by adsorption-induced surface blocking effects, leading to measurable capacitance variation in the presence of glucose at the Mn3O4/ analyte interface. The choice of Mn3O4is motivated by its chemical stability, abundant surface-active sites, and compatibility with low-temperature inkjet printing. The fully printed device demonstrates mechanical flexibility, low material consumption, and scalable fabrication, making it suitable for wearable POC applications. The fabricated sensor exhibited a linear detection range of 0.2–7 mM and achieved a limit of detection (LOD) of 0.546 mM, demonstrating stable and reliable sensing performance.