Optical Fiber TFBG Glucose Biosensor via pH-Sensitive Polyelectrolyte Membrane.

Area of Science:

• Biomedical Engineering
• Chemical Sensing
• Optical Biosensors

Background:

• Glucose monitoring is crucial for diabetes management.
• Existing biosensors face limitations in sensitivity, stability, and real-world applicability.

Purpose of the Study:

• To develop a novel, highly sensitive glucose biosensor.
• To leverage tilted fiber Bragg grating (TFBG) technology for enhanced glucose detection.
• To explore the use of pH-responsive polyelectrolyte multilayers for biosensing.

Main Methods:

• Fabrication of a TFBG functionalized with a polyelectrolyte multilayer (PEM) membrane.
• Immobilization of glucose oxidase (GOD) onto the PEM.
• Utilizing layer-by-layer self-assembly of poly(ethylenimine) (PEI) and poly(acrylic acid) (PAA) for PEM construction.
• Monitoring shifts in TFBG cladding mode resonance wavelengths in response to pH changes induced by glucose oxidation.

Main Results:

• The optimized biosensor (PEI/PAA)4(PEI/GOD)1 demonstrated high sensitivity.
• Achieved a wide measurement range (10⁻⁸ to 10⁻² M) with a low detection limit of 27.7 nM.
• Exhibited a fast response time of approximately 60 seconds and excellent specificity.
• Showcased robust performance in biological matrices (rabbit serum, artificial urine) with high recovery rates (93-102%).

Conclusions:

• The developed TFBG-based glucose biosensor offers a promising platform for sensitive and rapid glucose detection.
• Its stability, temperature insensitivity, and miniaturization potential make it suitable for point-of-care testing and clinical glucose monitoring.
• This novel biosensor has significant potential for improving diabetes management and disease monitoring.