Nanozyme-based sensitive ratiometric fluorescence detection platform for glucose.

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Materials Science

Background:

• Abnormal blood glucose levels pose significant health risks, necessitating sensitive and accurate detection methods.
• Carbon-based nanozymes are emerging as promising tools for various applications, including biosensing.
• Existing glucose sensing technologies often face limitations in sensitivity, accuracy, or complexity.

Purpose of the Study:

• To develop a novel nanozyme-based ratiometric fluorescence sensing platform for highly sensitive and accurate glucose detection.
• To utilize the catalytic activity of copper-doped carbon nanozymes (CuAA) and the fluorescence properties of Mg/N-doped carbon quantum dots (Mg-N-CQDs).
• To establish a reliable method for glucose determination in biological samples like human serum.

Main Methods:

• Constructed a sensing system integrating glucose oxidase (Glu Ox), CuAA with peroxidase-like activity, and Mg-N-CQDs.
• Employed tandem catalysis where Glu Ox oxidizes glucose to H2O2, and CuAA catalyzes the formation of fluorescent 2,3-diaminophenazine (DAP).
• Utilized the inner-filter effect (IFE) between DAP and Mg-N-CQDs for ratiometric fluorescence signal generation (I558/I444).

Main Results:

• The ratiometric fluorescence signal (I558/I444) showed a linear response to glucose concentration from 2 to 400 μmol L−1.
• Achieved a low limit of detection (LOD) of 1.56 μmol L−1 for glucose.
• Demonstrated the practical applicability of the platform for glucose determination in human serum with satisfactory recovery and precision.

Conclusions:

• The developed nanozyme-based ratiometric fluorescence platform offers a sensitive and accurate method for glucose detection.
• The combination of CuAA nanozymes and Mg-N-CQDs, coupled with IFE, provides a robust sensing mechanism.
• This platform holds potential for clinical diagnostics and monitoring of glucose levels.