Reusable screen-printed electrochemical sensor for real-time glucose monitoring

Abstract

A reusable non-enzymatic glucose sensor (RGS) was created using a modular 3D-printed housing and a 2D plotter-based screen-printing technique in response to the increasing need for inexpensive, reusable, and low-waste glucose monitoring devices. The reference and counter electrodes were Ag/AgCl electrodes, while the working electrode was a copper nanoparticle (CuNP) ink. Optimizing electrode geometry with COMSOL Multiphysics led to increased sensitivity and consistent current distribution. XRD and FTIR structural characterisation verified the CuNP ink’s crystalline and chemical characteristics. A linear amperometric response to glucose concentrations ranging from 5 to 30 mM was shown by electrochemical evaluation in phosphate-buffered saline (PBS), with a sensitivity of 451.82 µA mM⁻¹ cm⁻² and a detection limit of 0.3 mM. With good repeatability and reproducibility across several printed electrodes, the sensor demonstrated outstanding analytical performance. Studies on long-term stability revealed a 97.18% signal retention over a 15-day period. Consistent current responses and improved reusability were made possible by the interchangeable working-electrode cartridge. A scalable and sustainable fabrication approach for creating flexible and reusable glucose-sensing devices appropriate for regular monitoring applications is presented in this work.