A novel glucose biosensor using bi-enzyme incorporated with peptide nanotubes

Area of Science:

• Biomaterials Science
• Nanotechnology
• Electrochemistry
• Biosensors

Background:

• Development of efficient and stable biosensors is crucial for accurate glucose monitoring.
• Enzyme immobilization techniques significantly impact biosensor performance and longevity.
• Peptide nanotubes (PNTs) offer a promising biocompatible nanoenvironment for enzyme encapsulation.

Purpose of the Study:

• To develop a novel amperometric glucose biosensor using bio-inspired peptide nanotubes (PNTs) for enzyme encapsulation.
• To co-immobilize horseradish peroxidase (HRP) and glucose oxidase (GO(x)) on a gold nanoparticle (AuNP)-modified electrode.
• To evaluate the biosensor's performance, stability, and applicability in real samples.

Main Methods:

• Fabrication of a biosensor electrode using a composite of AuNP-SAM-PNT/HRP-GO(x).
• Enzyme encapsulation within PNTs and co-immobilization on an electrode surface modified with a binary self-assembled monolayer (SAM) of MPA and TDT.
• Performance characterization including detection limit, sensitivity, pH, response time, selectivity, reproducibility, and stability testing.

Main Results:

• The PNT-based biosensor exhibited a linear response to glucose in the concentration range of 0.5-2.4 mM (R²=0.994).
• Achieved a maximum sensitivity of 0.3 mA M⁻¹ and excellent reproducibility (RSD of 1.95%).
• PNT-encapsulated enzymes retained over 85% of their initial current response after one month of storage, indicating enhanced stability.

Conclusions:

• The developed AuNP-SAM-PNT/HRP-GO(x) biosensor offers a stable and efficient platform for amperometric glucose detection.
• The PNT encapsulation provides a biocompatible nanoenvironment, enhancing enzyme activity and direct electron transfer.
• The biosensor shows significant potential for practical applications in real sample analysis due to its performance and stability.