A direct electrochemical biosensor for rapid glucose detection based on nitrogen‐doped carbon nanocages

Abstract Given the increasing number of diabetic patients, rapid and accurate detection of glucose in body fluids is critical. This study developed a direct electrochemical biosensor for glucose based on nitrogen‐doped carbon nanocages (NCNCs). NCNCs possess a large specific surface area of 1395 m 2 ·g −1 , a high N atomic content of 9.37% and good biocompatibility, which is favorable for enzyme loading and electron transfer. The surface average concentration of electroactive glucose oxidase on NCNCs was 2.82 × 10 –10 mol·cm −2 . The NCNC‐based direct electrochemical biosensor exhibited a high sensitivity of 13.7 μA·(mmol·L −1 ) −1 ·cm −2 , rapid response time of 5 s and an impressive electron‐transfer‐rate constant ( k s ) of 1.87 s −1 . Furthermore, we investigated an NCNC‐based direct electron transfer (DET) biosensor for sweat glucose detection, which demonstrated tremendous promise for non‐invasive wearable diabetes diagnosis.