Amperometric glucose biosensor based on self-assembly hydrophobin with high efficiency of enzyme utilization

Area of Science:

• Biomaterials Science
• Biosensor Technology
• Protein Engineering

Background:

• Hydrophobins are natural, self-assembling proteins with excellent biocompatibility.
• Their ability to form ordered structures on surfaces makes them ideal for biomolecule immobilization.
• Class II hydrophobin HFBI was chosen for its suitability as an enzyme immobilization matrix.

Purpose of the Study:

• To develop an amperometric glucose biosensor using HFBI as an enzyme immobilization matrix.
• To optimize HFBI film permeability for efficient H(2)O(2) transport and interference blocking.
• To evaluate the performance of the HFBI-based glucose biosensor.

Main Methods:

• Electrode modification with HFBI and glucose oxidase (GOx).
• Optimization of HFBI concentration for film permeability.
• Monitoring HFBI self-assembly and GOx immobilization using Quartz Crystal Microbalance (QCM).
• Surface characterization using Scanning Electron Microscopy (SEM).

Main Results:

• The HFBI-based biosensor exhibited a rapid response time (<6s) and a low limit of detection (0.09 mM).
• Achieved a wide linear range (0.5–20 mM), high sensitivity (4.214 x 10⁻³ A M⁻¹ cm⁻²), and excellent selectivity, reproducibility, and lifetime.
• Demonstrated high enzyme utilization efficiency, with up to 712 µA current per unit GOx activity.

Conclusions:

• HFBI serves as a promising, biocompatible immobilization matrix for biosensor development.
• The optimized HFBI film allows efficient analyte and product diffusion while preventing interference.
• This all-protein modified biosensor shows high performance, suitable for further research in biosensing and surface functionalization.