A New Chitosan-Modified Paper-Based SERS Glucose Sensor with Enhanced Reproducibility, Stability, and Sensitivity for...

Area of Science:

• Materials Science
• Analytical Chemistry
• Biomedical Engineering

Background:

• Accurate glucose monitoring is crucial for diabetes management.
• Existing glucose detection methods often rely on enzymatic reactions, which can be unstable and costly.
• Development of sensitive, stable, and label-free glucose sensors is highly desirable.

Purpose of the Study:

• To develop a highly reproducible, stable, and sensitive cellulose paper-based Surface-enhanced Raman scattering (SERS) sensor for non-enzymatic, label-free glucose detection.
• To functionalize a cellulose paper substrate with chitosan and silver nanoparticles for enhanced SERS performance.
• To investigate the sensor's performance in detecting glucose in human blood serum samples.

Main Methods:

• Fabrication of a cellulose paper (CP) substrate modified with chitosan (CS) and silver nanoparticles (AgNPs).
• Self-assembly of 4-mercaptophenyl boronic acid (MPBA) on the CP/CS/AgNPs surface to create the SERS sensor (CP/CS/AgNPs/MPBA).
• Characterization using SEM, EDX, FT-IR, and XRD; glucose detection via SERS intensity monitoring at 1072 cm⁻¹.

Main Results:

• The CP/CS/AgNPs/MPBA sensor demonstrated a high analytical enhancement factor (AEF) of 3.4 × 10⁷.
• Excellent reproducibility (<7%), stability (>5 weeks), and selectivity towards other metabolic compounds were achieved.
• High sensitivity with a limit of detection (LOD) of 0.74 mM and a linear dynamic range of 1.0–7.0 mM was observed.
• Satisfactory recovery results were obtained for glucose detection in spiked and non-spiked human blood serum samples.

Conclusions:

• The developed paper-based SERS sensor is a promising platform for non-enzymatic, label-free glucose detection.
• The sensor exhibits excellent analytical performance, including high sensitivity, reproducibility, and stability.
• The practical application in real biological samples demonstrates its potential for clinical diagnostics.