An Electrochemical Microneedle Biosensor with Wide Linear Range for Continuous Glucose Monitoring

Wearable microneedle-based glucose sensor is a highly promising device for long-term continuous glucose monitoring. In particular, it is essential to develop minimally invasive a glucose sensor with long lifetime, wide linear range, and low limit of detection by ensuring long-term enzyme stability and reducing biofouling. In this study, we present a fully integrated polymeric microneedle sensor system with wireless and in vivo testing for real-time sensing of glucose levels in interstitial fluid (ISF). The developed device is compatible with a customized mobile apps for data visualization and collection. The microneedle glucose sensor utilizes a sandwich-type enzyme immobilization technique, enhanced by a newly developed double-layer permselective membrane coating, resulting in an impressive wide linear range of 0-31.45 mM and a low limit of detection (
$1.8\ \mu\mathrm{M}$
) for glucose monitoring, while effectively minimizing fouling in ISF. Furthermore, the performance of the developed microneedle glucose sensor was validated through clinical testing using a rabbit model. The results provide evidence of its reliability and effectiveness in accurately measuring glucose levels in ISF.