Amino-functionalized MIL-101(Fe)-confined Au nanostructures for advanced electrochemical detection of H2O2 in Alzheimer's disease research.

Oxidative stress is a fundamental pathological contributor to Alzheimer's disease and is closely linked to amyloid-beta-mediated toxicity, tau dysregulation, mitochondrial impairment, and progressive neuronal degeneration. Among the associated reactive oxygen species, hydrogen peroxide (H2O2) is a mechanistically relevant redox intermediate and an important oxidative stress biomarker. Herein, an Au@NH2-MIL-101(Fe) hybrid was rationally engineered as an electrocatalytically active sensing interface for H2O2 determination. The hybrid was constructed by integrating conductive Au nanodomains with an amino-functionalized Fe-based metal-organic framework, thereby combining the high surface area, porous architecture, and accessible coordination environment of NH2-MIL-101(Fe) with the superior conductivity and catalytic activity of Au. Electrochemical investigations revealed that Au@NH2-MIL-101(Fe)/SPCE exhibited substantially enhanced interfacial electron-transfer kinetics and electrocatalytic reduction of H2O2 relative to bare SPCE, MIL-101(Fe), and NH2-MIL-101(Fe). Under optimized conditions, the sensor delivered a linear range of 0.01 to 429.7 μM and a limit of detection of 0.063 µM. In addition, the platform showed good selectivity, operational stability, reproducibility, and satisfactory performance in H2O2-spiked serum and urine samples, highlighting its promise for oxidative stress-related electroanalysis relevant to Alzheimer's disease.