MXene-based hybrid nanocomposites for enhanced enzyme-electrode electron transfer for high-performance glucose...

The growing global incidence of diabetes highlights the urgent need for glucose biosensors with superior sensitivity, low detection limits, and high selectivity, for next-generation health monitoring. In this study, we report a high-performance enzymatic glucose biosensor based on a hierarchically assembled MXene/AuNPs/polypyrrole/chitosan/glucose oxidase (MAPCG) nanocomposite electrode. Structural and morphological analyses revealed that the incorporation of AuNPs and an in situ-formed PPy coating effectively suppresses MXene restacking, enhances porosity, and facilitates efficient electron transport. Electrochemical characterization reveals accelerated interfacial electron-transfer kinetics and enhanced enzymatic stability of the MAPCG electrode. The biosensor achieved a high sensitivity of 110.6 μA/mM/cm², a broad linear range of 0.02-13 mM, and a detection limit as low as 4.23 μM, ensuring accurate detection across clinically relevant glucose levels. Moreover, the sensor displayed excellent selectivity toward glucose in the presence of common interfering species, a rapid response time of 1-2 s, high reproducibility (RSD = 1.64%), and long-term operational stability (91% signal retention after 30 days). The biosensor also demonstrated high recovery rates (94-98.7%) in human serum samples, confirming its strong potential for reliable and direct glucose monitoring in clinical applications.