A novel electrochemical microneedle sensor for highly sensitive real time monitoring of glucose

Glucose is one of the most significant biomarkers due to its association with numerous diseases related to blood glucose concentration. In this study, a novel electrochemical microneedle sensor (EMS) for highly sensitive, high spatiotemporal resolution, real time glucose monitoring is developed. Initially, the sensor is modified by electrochemically depositing gold nanoparticles to enhance its conductivity. Subsequently, a platinum sensing layer is deposited onto the sensor to realize the detection of hydrogen peroxide. Glucose oxidase (GOx) is then immobilized onto the sensor by immersing it in an O-phenylenediamine solution and electro-polymerizing O-phenylenediamine. A polyurethane-based biological protective film is applied to protect the electrode from interference by large proteins and cell deposition in body fluid. The prepared EMS demonstrates excellent selectivity for glucose detection (0.818 μA/mM) over a broad range (0 to 20 mM). Furthermore, clinical serum glucose testing experiments verified the sensor’s performance, showcasing its potential for biomedical research and clinical practice. This EMS offers a less invasive and more convenient method for highly sensitive, high spatiotemporal resolution, real time glucose monitoring. Moreover, this electrochemical implantable sensor provides a minimally invasive and convenient solution for continuous monitoring of other biomarkers.