Impedance-Based Polymer Microneedle Patch Sensor for Continuous Interstitial Fluid Glucose Monitoring

Early diagnosis and control of blood glucose is essential for effective prevention and management of diabetes-related complications. This study aims to develop a microneedle-type glucose sensor patch for minimally invasive, painless and continuous glucose monitoring. In situ monitoring of glucose concentration in interstitial fluid using polymeric microneedle arrays is the method used in this study. The experimental section included four subsections, namely substrates fabrication, sensor fabrication, and characterization of the glucose sensor based on microneedle patches. The experimental findings demonstrate the successful penetration of cylindrical microneedles into skin tissue with minimal force, reaching a depth of approximately 520 μm. The microneedle sensor was produced with high precision using the CMOS process, and the immobilization of glucose oxidase was confirmed through phase angle changes. After conducting long-term tests, the sensor was found to be effective for up to 7 days. Glucose concentration measurements were conducted using the developed sensor, resulting in fitted curves with a mean slope of -27.18 and a mean intercept of 197.27. Random glucose concentration tests were conducted, and the range of values obtained shows strong correlation with those obtained from commercially available glucose detectors. MARD ranges from -0.5% to 11.97%. These results suggest the potential for the microneedle sensor to be used as a reliable and accurate tool for glucose monitoring. The study provides a promising approach for developing a wearable and minimally invasive and painless glucose sensor for continuous glucose monitoring.